ArticlePDF Available

Sustainability of Social Housing in Asia: A Holistic Multi-Perspective Development Process for Bamboo-Based Construction in the Philippines

Authors:
  • Base Bahay Foundation Inc.

Abstract and Figures

This paper highlights the need for a more inclusive and sustainable development of social housing in rapidly developing countries of Asia, Latin America, and Africa. At the example of the Philippines, a multi-perspective development process for a bamboo-based building system is developed. Sustainability Assessment Criteria are defined through literature review, field observations and interviews with three stakeholder clusters: (1) Builders and users of traditional bamboo houses in the Philippines; (2) Stakeholders involved in using forest products for housing in other countries around the world; and (3) Stakeholders in the field of social housing in the Philippines. Through coding and sorting of data in a qualitative content analysis, 15 sustainability assessment criteria are identified clustered into the dimensions society, ecology, economy, governance, and technology. Guided by the sustainability criteria and four implementation strategies: (A) Research about and (B) Implementation of the building technology; (C) Participation and Capacity Building of Stakeholders; and (D) Sustainable Supply Chains, a strategic roadmap was created naming, in total, 28 action items. Through segmentation of the complex problem into these action items, the paper identifies one-dimensional methods leading to measurable, quantitative endpoints. In this way, qualitative stakeholder data is translated into quantitative methods, forming a pathway for a holistic assessment of the building technologies. A mid-point, multi-criteria, or pareto decision-making method comparing the 28 endpoints of the alternative to currently practiced conventional solutions is suggested as subject for further research. This framework paper is a contribution to how sustainable building practices can become more inclusive, incorporating the building stock of low-income dwellers. It bridges the gap between theoretical approach and practical applications of sustainability and underlines the strength of combining multi-dimensional development with stakeholder participation.
Content may be subject to copyright.
sustainability
Article
Sustainability of Social Housing in Asia: A Holistic
Multi-Perspective Development Process for
Bamboo-Based Construction in the Philippines
Corinna Salzer 1, *, Holger Wallbaum 1, Luis Felipe Lopez 2and Jean Luc Kouyoumji 3
1Chair of Sustainable Building, Department of Civil and Environmental Engineering,
Chalmers University of Technology, SE-41296 Gothenburg, Sweden; holger.wallbaum@chalmers.se
2
Base Bahay, Chino Roces Avenue, 1200 Makati City, Metro Manila, Philippines; Luis.Lopez@base-bahay.com
3Bambou Science et Innovation; 14 rue André Messager, 33 520 Bruges, France; jlk@bambouscience.fr
*Correspondence: salzer@chalmers.se; Tel.: +65-88-696-542
Academic Editors: Thorsten Schuetze, Hendrik Tieben, Lorenzo Chelleri, York Ostermeyer and Marc Wolfram
Received: 30 November 2015; Accepted: 26 January 2016; Published: 6 February 2016
Abstract:
This paper highlights the need for a more inclusive and sustainable development of social
housing in rapidly developing countries of Asia, Latin America, and Africa. At the example of
the Philippines, a multi-perspective development process for a bamboo-based building system
is developed. Sustainability Assessment Criteria are defined through literature review, field
observations and interviews with three stakeholder clusters: (1) Builders and users of traditional
bamboo houses in the Philippines; (2) Stakeholders involved in using forest products for housing in
other countries around the world; and (3) Stakeholders in the field of social housing in the Philippines.
Through coding and sorting of data in a qualitative content analysis, 15 sustainability assessment
criteria are identified clustered into the dimensions society, ecology, economy, governance, and
technology. Guided by the sustainability criteria and four implementation strategies: (A) Research
about and (B) Implementation of the building technology; (C) Participation and Capacity Building
of Stakeholders; and (D) Sustainable Supply Chains, a strategic roadmap was created naming, in
total, 28 action items. Through segmentation of the complex problem into these action items, the
paper identifies one-dimensional methods leading to measurable, quantitative endpoints. In this way,
qualitative stakeholder data is translated into quantitative methods, forming a pathway for a holistic
assessment of the building technologies. A mid-point, multi-criteria, or pareto decision-making
method comparing the 28 endpoints of the alternative to currently practiced conventional solutions
is suggested as subject for further research. This framework paper is a contribution to how
sustainable building practices can become more inclusive, incorporating the building stock of
low-income dwellers. It bridges the gap between theoretical approach and practical applications
of sustainability and underlines the strength of combining multi-dimensional development with
stakeholder participation.
Keywords:
stakeholder participation; sustainability criteria; sustainable building; social housing;
multi-perspective development process; bamboo
1. Introduction
This section introduces the case study of the paper. It is organized into (Section 1.1) Motivation,
(Section 1.2) Research Objectives and Questions, and (Section 1.3) Limitations.
Sustainability 2016,8, 151; doi:10.3390/su8020151 www.mdpi.com/journal/sustainability
Sustainability 2016,8, 151 2 of 26
1.1. Motivation
Building practices around the globe are a major consumer of resources and energy, while
producing significant emissions and waste [
1
]. Climate change and the environmental impact of
construction make sustainable buildings an urgent requirement. Acknowledging this fact, the concept
of sustainable building has spread widely [
2
]. In several countries, sustainable construction has already
been institutionalized, such as in Switzerland through SIA 112/1 [
3
]. While the call for sustainable
buildings is urgent, this holds true also, but not only, for advanced built environments. In rapidly
developing urban centers in Asia-Pacific, the consideration of sustainability as design guideline is still
limited to selected, advanced construction projects. Incorporating the building stock of low-income
groups, has however received only little attention in research so far [
2
,
4
,
5
]. Tremendous urban poverty
and urban growth rates in Latin America, Africa, and Asia-Pacific require a more inclusive and
sustainable urban development [
6
]. Today, approximately 30 percent of the urban population in
Asia-Pacific, which accounts for 570 Million people, lives in houses which are defined as inadequate
by the United Nations [
7
]. Adequacy refers to a shelter providing safety and privacy, allowing healthy
living as well as access to utilities, public services, and livelihood. The building stock of low-income
groups is often characterized by substandard practices or temporary shelters, which can lead to fatal
failures during earthquakes, typhoons, or floods [
8
,
9
]. Since the Philippines belong to the most affected
countries by Climate Change around the globe [
10
,
11
], future extreme impacts are expected even more
frequently, which causes vicious cycles of vulnerability for the urban poor. While adequate housing is
a desire of most affected people, conventional building technologies, such as concrete and steel, as well
as the systems to finance and obtain them, are mostly not adjusted to the affordability of low-income
dwellers [
12
]. Collective efforts by governments, private sector, urban poor themselves and further
relevant stakeholders is needed to provide low-income housing at scale and in a more socially-inclusive
manner [
13
]. Solutions for more economic, disaster resistant and socially-inclusive housing are needed,
which also provide more environmentally-friendly pathways for urban development. This paper
addresses therefore the need for more sustainable housing solutions for low-income groups with the
example of the Philippines.
The use of locally available raw materials is a potential to be explored in this regard. One
material with interesting potential for the Philippines is the fast growing, widely spread bamboo. Since
centuries, traditional bamboo housing can be found in the rural Philippines [
14
]. The use of bamboo in
urban Philippines, however, is limited to informal settlements and non-load-bearing applications. For
an application in cities, conventional concrete and steel are considered more modern, safe, and less
maintenance intensive. Traditional bamboo construction has never undergone a strategic technical
review to assess its adaptation potential to an urban and/or disaster prone context.
The contribution of this paper is to describe sustainability criteria and a pathway according
to which bamboo-based construction needs to develop for contributing to the described need of
adequate social housing in the Philippines. The roadmap presented in this paper provides the theoretic
framework, which once implemented in actuality, will allow the use of Sustainability Assessments as
a decision-tool as suggested in [15].
1.2. Research Objectives and Questions
The general objective of the paper is to develop a roadmap for transforming the potential bamboo
raw material into a sustainable building technology suitable for social housing in the Philippines.
This general objective is obtained through a set of specific objectives:
1.
To define meaningful, context-specific Sustainability Assessment Criteria for bamboo-based
building technologies in social housing of the Philippines
Ñ
What are requirements, barriers, and opportunities of stakeholders in social housing and for using
bamboo as a construction material in this context?
ÑWhich pillars of sustainability are tackled through these requirements?
Sustainability 2016,8, 151 3 of 26
ÑIn which Sustainability Assessment Criteria can these requirements be translated?
2.
To define a Strategic Development Roadmap for the alternative building method, which
transforms the theoretic criteria and requirements into implementable, measurable results
ÑWhat are general strategies for implementing the theoretic context on the ground?
Ñ
To which concrete action items lead the strategies for implementation and the Sustainability Criteria?
ÑThrough which methods can measurable results within these action items be generated?
1.3. Limitations
This section highlights the limitations of this research work:
-
The paper focuses on presenting Sustainability Assessment Criteria and Strategic Development
Roadmap for developing a material potential into a sustainable building technology for social
housing. Subject to further research are comprehensive test results about alternative building
technology, and a multi-criteria ranking in comparison to conventional building methods. This
introductory method paper does therefore not conclude with a recommendation for or against
the alternative building technology.
-
The paper focuses on building technologies as an entry point for improvement in social housing.
Aspects directly related to the value chain of the technology can be shaped or even controlled
by technology providers and are therefore analyzed in the paper. However, an innovation in
the construction sector does not likely change wider conceptual barriers on sustainable urban
development and social housing [
16
]. An adjustment to such or, at best, influence of it can
be achieved by long term multi-stakeholder dialogues and high-level advocacy. For a system
change at scale, aspects such as land tenure, housing finance, governance, and policies in urban
development, empowerment, and organization of informal communities, income generation
for marginalized groups as well as basic services and infrastructure of settlements have to
be addressed.
-
The paper uses the terminology of an urban context, since this is considered a more conservative
boundary condition for the technology to be established on the market. ‘Urban’ relates to the
compliance with urban policies and performance requirements. It does not exclude the technology
from being applied in rural areas, in which a higher degree of regulatory freedom might exist.
2. Method
As introduced in the previous chapter, this paper looks at the need of Social Housing in the
Philippines and analyses the potential of the alternative raw material bamboo for it. The method section
is divided into two main sections: In 2.1 Definition of Sustainability Assessment Criteria, a theoretical
context on requirements to be considered for the technology evaluation is provided. In 2.2 Strategic
Development Roadmap, the pathway is shown how the raw material potential can be transformed
into a building concept for social housing under consideration of the theoretical context. The
roadmap specifies action items and defines methods for generating one-dimensional, quantitative data.
Once implemented, the latter will allow a performance assessment of the alternative in all relevant
dimensions individually. Since both steps are fundamentally connected to perspectives of stakeholders
from various backgrounds, this process is named a Multi-Perspective Development Process (MPDP). It can
be considered the first part of Multi-Criteria Decision Making (MCDM). The latter is recognized and
described as one possible concept for decision making in the field of sustainable development. It is widely
recognized and applied in several disciplines, such as natural resource management [
17
], biofuel [
18
],
farming [
19
], transportation [
20
], energy and reviews of energy sector applications [
21
,
22
], solid waste
management [
23
] or public investment [
24
]. In [
25
], over 403 fuzzy MCDM techniques and applications
published within two decades were comprehensively assessed and compared. Engineering was ranked
the most common field of application. In the field of civil engineering, it was applied for building
Sustainability 2016,8, 151 4 of 26
materials [
26
], housing related choices [
27
29
], or renovation choices [
30
]. Further, the inclusion of
stakeholder perspectives was piloted in combination to using MCDM [
31
]. A majority of the product
related studies cited above, compared technologies that are already established on the market and
the focus is set on the ranking and decision-making through methodologies such as SAW, TOPSIS, or
COPRAS [
30
]. In contrary to those studies, the case of this paper requires the development of a raw
material into a technology first and foremost. The definition of sustainability assessment criteria and
a roadmap for the development of the technology and data to assess it, was in the focus of the paper.
Selected one-dimensional data results are provided in the results section, however, the paper calls
for a comprehensive production and evaluation of all suggested data sets needed. Only the latter
will enable comparing the alternative building method holistically to current conventional practices.
While the ranking and decision-making of a MCDM is not part of this paper, it remains an objective
for further research.
2.1. Definition of Sustainability Assessment Criteria
Literature reviews have shown that a mismatch between scope and actually obtained results
can be observed when inappropriate sustainability assessment criteria are chosen. This can happen
due to a supply, rather than a demand driven approach of using existing criteria [
32
]. To ensure
a suitable selection of Sustainability Criteria, this research systematically involved stakeholder
perspectives. In [
33
], the relevance of stakeholder involvement for environmental management
has been analyzed according to disciplines and geographic context and various participatory methods
were categorized. It is stated in [
34
] that a systematic approach for stakeholder engagement in
the construction sector is a requirement for achieving overall sustainability. Also in other sectors,
the involvement of stakeholders’ perspectives has been recognized as an important method for the
definition of Sustainability Assessment Criteria [
35
]. In the Philippines, stakeholder involvement
has been confirmed as a significant method for disaster risk reduction [
36
]. Especially in developing
contexts where sustainability is the goal, enhanced mechanisms for participation throughout the
lifecycle of planning and implementation are needed [
37
]. Depending on the respective perspective
of stakeholders, different rankings are set in weighing Sustainability Criteria, but homogeneous
stakeholders‘ preferences typologies can be identified in stakeholder sub-groups [
38
]. Therefore,
not only the choice of the participatory method, but also the selection of stakeholder groups is critical.
For the choice of stakeholders to be interviewed or involved, [
15
,
34
,
39
] distinguish two general
approaches: a top-down or expert-driven approach and a bottom-up or stakeholder-driven approach.
A combination of both reflects most recent scientific recommendations. It ensures the comprehensive
capture of barriers and opportunities and enables participation and ownership throughout the layers of
society that are affected by a case. With that, the gap between theory and implementation, as mentioned
by [
34
] can be bridged. The expert and grassroots stakeholders for this research were identified
through the context of the case being social housing in the Philippines and bamboo utilization for housing.
Further, both national and international perspectives were captured, leading to the following three
stakeholder clusters:
(1) Builders and users of traditional bamboo houses,
(2) Stakeholders involved in using forest products for housing in other parts of the world, and
(3) Stakeholders in the field of social housing in the Philippines.
A detailed description of the samples in these stakeholder groups is described at the end of this
the Section 2.1.
Stakeholder requirements are captured through cognitive interviews for which the interview
principles for research and evaluation of [
40
] were followed. The interviews generated qualitative data
on requirements, barriers and opportunities from multiple stakeholder perspectives. Depending on
the background and context of the stakeholder group, either a less-formal/-structured Ethnographic
Interview type, or an Interview Guide Approach was chosen. The ethnographic interviews provide high
Sustainability 2016,8, 151 5 of 26
flexibility but nevertheless follow a specific, implicit research agenda. The interview guide approach
provides more guidance on general themes that were to be captured by all stakeholder groups, and
with that provide more comparability, but still allows flexibility to incorporate individual perspectives
and requirements compared to standardized interviews, which follow exact wordings for every
stakeholder [
40
]. The interview guides, listing general questions and themes that were developed for
stakeholder groups are attached in Appendix. Special care was set on the formulation of the questions
in the interview guide, following the principles of [
40
], being: simple, non-irritating, understandable in
a cross-cultural context, bias-free, and open-ended. Probing questions were included in the interviews
to verify viewpoints. Both descriptive or knowledge-based questions and interpretive or attitudinal
questions were included. In addition to interview data, Field Inspections or Direct Observations were
carried out over a period of four years. These were documented in written and pictured field reports,
following the field observation guide for qualitative analysis provided in [
40
]. The field observations
contain further ethnographic interviews as well as contextual information noted on the ground.
Barriers and opportunities, expressed by stakeholders or documented in field observations, were
transformed in a qualitative Content Analysis to elicit most suitable sustainability criteria for the given
case. The content analysis was done manually without the use of data management software. Common
scientific guidelines for this process were applied: Through coding, sorting, and sifting, large quantities
of qualitative information were reduced in volume in order to derive patterns:
-
As first level sorting, a barrier or opportunity was coded into one or several pillars of sustainability.
This deductive approach bases on existing concepts of sustainability, where it is commonly
accepted, that the nature of today’s global problems is complex and multi-dimensional [
41
].
Five dimensions were adopted for the given case: in line with most common definitions of
sustainability [
42
], the pillars society, environment, and economy are denominated. Additionally,
the relevance of governance is highlighted, especially in development cooperation [
43
]. Further,
when dealing with products, such as in [
23
] or this case, the technical performance of products is
added as an additional pillar.
-
As second level sorting, several sampling strategies, described in [
44
], were applied to identify
common patterns in the qualitative data: (1) Group characteristic sampling, identifying patterns for
several stakeholders in a group without neglecting their diversity, (2) Instrumental-use multi-case
sampling, for generating actionable, useful findings, and (3) Comparison-focused sampling, for
understanding similarities and differences between cases that can be compared to the present case.
-
As third level, Literature review and field observations, where available, were used to triangulate
identified requirement patterns.
At the end of this process, raw data had been assembled and written-down in structured, narrative
case studies. These narratives are presented in the results section.
In order to move from case studies on stakeholder groups to an analytical framework, the
content analysis then derived Sustainability Criteria from the identified patterns. This part can be
described as Analytic Induction, as it moves from existing concepts to generating a new, case-specific
framework. Through Dichotomizing, or assigning symbols to a pattern, the stakeholder group patterns
were translated to Sustainability Criteria:
-
When an issue was only expressed by one stakeholder or not expressed or noted at all within the
stakeholder group or case, the respective criterion was left empty.
-
When an issue was expressed frequently among the stakeholder responses of a group, and it was
further described:
To act as driver, incentive or opportunity for a technology, the respective criterion was
assigned with “+”.
To act as barrier or hindrance for a technology, the respective criterion was assigned with “
´
”.
Sustainability 2016,8, 151 6 of 26
To act in some perspectives as a barrier, in others as an opportunity for a technology,
the respective criterion was assigned with “˘”.
In Figure 1, we visualized how qualitative data is sorted and processed in a content analysis into
sustainability criteria:
Sustainability2016,8,1516of25
Figure1.StepstoobtainSustainabilityCriteriafrommultiperspectivestakeholderdata.
Inadditiontothemethoddescriptionabove,adetailedexplanationofthesamplesandinterview
guidesforthestakeholdercategoriesisdescribedbelow:
(1) Buildersandusersoftraditionalbamboohouses:Localbambooconstructionpracticeswere
documentedthroughfieldobservationinselectedareasofknownbambootradition.Overa
periodoffouryears,from2011to2015,asamplesizeofn=16fieldinspectionswereconducted
assummarizedinTable1.Atranslatorwithlocaldialectwasengagedwhereneeded.The
interviewguideinAppendix,TableA1wasusedtoobtaindata.
Table1.Sampledescriptionforfieldinspectionoflocalbamboopractices.
ID
No.
Geography Samplesize
(No.ofInspections,No.of
ConstructionPracticesPer
Inspection)
Time
Horizonfor
Inspections
Island
GroupRegionProvinces
1A1DVisayasWesternVisayasIloilo,Capiz,Aklan,Negrosn=4,>102011–2015
1E1FVisayasNegrosDumagueten=2,>102014–2015
1GLuzonCordilleraAbran=1,>102014
1H1ILuzonCentralTarlac,Pangasinann=2,>102014–2015
1J1MLuzonCalabarzonLaguna,Quezonn=4,>102011–2015
1N1OLuzonBicolAlbay,CamarinesSurn=2,>102013
1PMindanaoDavaoDavaon=1,>102012
(2) Stakeholdersinvolvedinusingforestproductsforhousinginotherpartsoftheworld:For
identifyingsuitablecasesforacrosscasepatternanalysis,thecriterionuseofaloadbearingforest
productforhousinginurbanareaswasapplied.Twocaseswereidentifiedwithsignificantfindings
onbarriersandopportunitiesfortheexistingcase.Thecoauthorsbroughtinrelevantknowhow
foreachoneofthecases(seeauthorcontributions).Thechosencasesandtheirsamplearestated
inTable2.
Table2.Sampledescriptionforinternationalcasesusingforestproductsforhousing.
IDNo.GeographyDescriptionSampleSize
(No.ofCases,MethodsperCase)
Time
Horizon
2ALatin
America
Bamboobased
construction
n=1,fieldsurvey,expertreview
author1and3,literaturereview2013
2BEuropean
Union
Timberbased
construction
n=2,expertreviewbyauthor1and4,
literaturereview2013–2014
Forobtainingdata,theinterviewandexpertreviewguideinAppendix,TableA2wasused.
Figure 1. Steps to obtain Sustainability Criteria from multi-perspective stakeholder data.
In addition to the method description above, a detailed explanation of the samples and interview
guides for the stakeholder categories is described below:
(1)
Builders and users of traditional bamboo houses: Local bamboo construction practices were
documented through field observation in selected areas of known bamboo tradition. Over
a period of four years, from 2011 to 2015, a sample size of n= 16 field inspections were
conducted as summarized in Table 1. A translator with local dialect was engaged where
needed. The interview guide in Appendix, Table A1 was used to obtain data.
Table 1. Sample description for field inspection of local bamboo practices.
ID
No.
Geography Sample Size (No. of Inspections,
No. of Construction Practices
Per Inspection)
Time
Horizon for
Inspections
Island Group Region Provinces
1A-1D
Visayas Western Visayas Iloilo, Capiz, Aklan, Negros n= 4, > 10 2011–2015
1E-1F Visayas Negros Dumaguete n= 2, > 10 2014–2015
1G Luzon Cordillera Abra n= 1, > 10 2014
1H-1I Luzon Central Tarlac, Pangasinan n= 2, > 10 2014–2015
1J-1M Luzon Calabarzon Laguna, Quezon n= 4, > 10 2011–2015
1N-1O
Luzon Bicol Albay, Camarines Sur n= 2, > 10 2013
1P Mindanao Davao Davao n= 1, > 10 2012
(2)
Stakeholders involved in using forest products for housing in other parts of the world: For
identifying suitable cases for a cross-case pattern analysis, the criterion use of a load-bearing forest
product for housing in urban areas was applied. Two cases were identified with significant findings
on barriers and opportunities for the existing case. The co-authors brought-in relevant knowhow
for each one of the cases (see author contributions). The chosen cases and their sample are stated
in Table 2.
Sustainability 2016,8, 151 7 of 26
Table 2. Sample description for international cases using forest products for housing.
ID No. Geography Description Sample Size (No. of Cases,
Methods per Case) Time Horizon
2A Latin America Bamboo-based
construction
n= 1, field survey, expert review
author 1 and 3, literature review 2013
2B European Union Timber-based
construction
n= 2, expert review by author 1
and 4, literature review 2013–2014
For obtaining data, the interview and expert review guide in Appendix, Table A2 was used.
(3)
Stakeholders in the field of social housing in the Philippines: This stakeholder cluster is the most
complex and manifold. For capturing the requirements of the cluster, five sub-stakeholder groups
were identified through a systemic description of the conceptual framework of social housing in
the Philippines by [
45
] as well as an analysis of the value chain of bamboo as building material
by [
46
]. For each sub-group, n= 6 individuals were interviewed, resulting to a total of thirty
interviews. All interviewed persons had an in-depth understanding of the Philippines, and have
either a profession in the commercial or social housing field, or belong to a potential customer
group. Half of the interviewees have followed pilot applications for modern bamboo housing
over a certain period of time, while the other half had an external perspective. A gender mix
between interviewees was considered. Below, the sub-groups are stated in Table 3, together with
a description of the sample:
Table 3. Sample description for social housing stakeholders in Philippines.
ID
No. Geography Description Sample Size (Background, No. of Stakeholders) Time Horizon
3A Philippines
Low-income
groups and their
organizations,
Housing clients
Grassroots leaders or individuals from four regions
with highest housing need:
- Central Luzon (n= 2)
- South Luzon (n= 1)
- West Visayas (n= 2)
- East Visayas (n= 1)
2013–2015
3B Philippines and
Regional
Policy makers and
policy advocators
such as
international
organizations
- Government Housing and Regulatory
Authorities (n= 2)
- Government Low-Cost Housing Finance
Authority (n= 1)
- Country Office of IO in Housing (n= 1)
- Regional Asia-Pacific Office of IO in Urban
Development (n= 1)
2013–2015
3C Philippines
Construction sector,
housing, or service
providers
- Private Sector Housing Provider (n= 2)
- NGO (n= 2)
- Social Enterprise (n= 2)
2013–2015
3D Philippines
Technical
professionals,
Scientists
- Practicing Civil Engineers (n= 2)
- Practicing Architects (n= 2)
- Material scientist/Forestry Experts (n= 2)
2013–2015
3E Philippines Raw material
suppliers
- Individual Provider (n= 1)
- Potential Provider (n= 1)
- Consolidator (n= 2)
-
Academe advocator for bamboo supply (n= 2)
2013–2015
For obtaining data in the stakeholder sub-groups, the following interview guides in Appendix
were used: Table A1 for stakeholder sub-group 3A, Table A3 for stakeholder sub-groups 3B–3D and
Table A4 for stakeholder sub-group 3E.
Sustainability 2016,8, 151 8 of 26
2.2. Strategic Development Roadmap
Irrespective of manifold theoretical approaches towards sustainability, there remains a gap
between theoretic, normative use of Sustainable Development as a Decision-Making strategy and
practical applications [
15
,
47
]. The overall target of the wider research project, to which this introduction
paper belongs, is a descriptive performance assessment comparing two actual technology solutions
with each other. This requires a proven data base and implementation track record for both
technologies- the currently applied, existing one and the alternative being currently only a theoretic
material potential. Therefore, the core of this paper is the formulation of a Strategic Roadmap, which
allows the development and implementation of the alternative construction technology. This paper
links theoretic sustainability criteria to an implementable roadmap for action. As shown in [
48
] for
several countries in Asia, it is deemed a crucial strength of sustainability indicator programs, when
they are anchored in long-term implementation strategies.
From the qualitative data obtained through stakeholder consultations, four general
Implementation Strategies were identified for creating data about the alternative building technology
as seen in Table 4:
Table 4. Implementation Strategies of the Technology Roadmap.
No. Implementation Strategy
1 Research about the building technology
2 Implementation of the building technology
3
Participation & Capacity Building of Stakeholders
4 Sustainable Supply Chains of raw material
The core development consists of research about and implementation of the technology. The
importance of developing a technology people-centered and along of client’s needs, as introduced
earlier, is named critical by numerous literature references [
13
,
34
,
37
] and institutions such as [
49
].
For the application of a forest product based technology at larger scale, a specific requirement is further
a sustainably generated, accessible supply of quality graded raw material. In [
50
] it is mentioned,
that in many economies such a bamboo supply chain has to be built-up first.
The four Implementation Strategies were then related to the Sustainability Criteria, to identify
concrete and implementable action items. As a result, each implementation strategy contains action
items across the pillars of sustainability. Figure 2shows how criteria and implementation strategies are
merged into a roadmap naming concrete action and the methods to obtain quantitative data per action:
The Implementation Strategies are recommended to be applied in parallel and iterations,
in order to provide relevant feedback loops between each other: Outputs of the research agenda are
translated into construction concepts. Through pilot applications barriers in realization are identified
and additional research questions can be formulated. This approach of iterative action research
acknowledges the importance of gradual system change developed over a period of time. Iterative
processes contribute to awareness raising, ownership, and steps-wise change and are specifically suited
for the introduction of alternative technologies with continuous stakeholder participation.
In order for action items to become measurable, a method for implementation has to be
allocated. [
32
] identified that a systematic and transparent selection of the method is still subject
to further research. Through segmentation of the complex problem Use of bamboo for social housing into
action items, the paper is able to identify individual one-dimensional methods per action item leading
to measurable endpoints. In this way, qualitative stakeholder data can be translated into quantitative
methods for data generation. The choice of quantitative methods for data generation was determined
by scientific quality and context related suitability. The combination of one-dimensional result into
a mid-point, multi-criteria, or pareto result such as in [
12
,
28
,
29
,
51
] still remains a topic for further
research. However, the pathway for a holistic assessment of the technologies is created.
Sustainability 2016,8, 151 9 of 26
Sustainability2016,8,1518of25
Asshownin[48]forseveralcountriesinAsia,itisdeemedacrucialstrengthofsustainability
indicatorprograms,whentheyareanchoredinlongtermimplementationstrategies.
Fromthequalitativedataobtainedthroughstakeholderconsultations,fourgeneral
ImplementationStrategieswereidentifiedforcreatingdataaboutthealternativebuildingtechnology
asseeninTable4:
Table4.ImplementationStrategiesoftheTechnologyRoadmap.
No. ImplementationStrategy
1Researchaboutthebuildingtechnology
2Implementationofthebuildingtechnology
3Participation&CapacityBuildingofStakeholders
4SustainableSupplyChainsofrawmaterial
Thecoredevelopmentconsistsofresearchaboutandimplementationofthetechnology.The
importanceofdevelopingatechnologypeoplecenteredandalongofclient’sneeds,asintroduced
earlier,isnamedcriticalbynumerousliteraturereferences[13,34,37]andinstitutionssuchas[49].For
theapplicationofaforestproductbasedtechnologyatlargerscale,aspecificrequirementisfurther
asustainablygenerated,accessiblesupplyofqualitygradedrawmaterial.In[50]itismentioned,that
inmanyeconomiessuchabamboosupplychainhastobebuiltupfirst.
ThefourImplementationStrategieswerethenrelatedtotheSustainabilityCriteria,toidentify
concreteandimplementableactionitems.Asaresult,eachimplementationstrategycontainsaction
itemsacrossthepillarsofsustainability.Figure2showshowcriteriaandimplementationstrategies
aremergedintoaroadmapnamingconcreteactionandthemethodstoobtainquantitativedataperaction:

Figure2.StepstoobtainaStrategicTechnologyDevelopmentRoadmap.
Figure 2. Steps to obtain a Strategic Technology Development Roadmap.
3. Results
This section documents the identified Sustainability Assessment Criteria and the action items and
methods within the Strategic Development Roadmap.
3.1. Sustainability Assessment Criteria
The Sustainability Assessment Criteria presented in this chapter are derived from qualitative data
about local practices, knowledge exchange through assessing bamboo construction in Latin America
and timber frame construction in Europe, as well as requirements expressed by multi-perspective
stakeholder groups in the pilot country. Themes of questions are documented in Appendix, while
flexibility was provided to deepen the interviews according to specific interviewee concerns. Results
are presented in each of the categories, before the summary of all criteria are stated.
3.1.1. Findings about Local Practices in Rural Areas of the Pilot Country
Sixteen field inspections and several transcripts of conversations with bamboo builders and
users per field inspection have been analyzed following the nine themes of questions documented in
Table A1. Mentioned requirements were coded into pillars of sustainability and sorted into the eight
sustainability criteria stated in Figure 3:
Sustainability 2016,8, 151 10 of 26
SUSTAINABILITY ASSESSMENT CRITERIA
No. Pillar of Sustainability Criteria (1)
Society
Technology
Economy
Ecology
Governance
1 Social acceptance & advocacy ´
2 Participation & identification
3 Capacity building ´
4 Income at local value chain +
5 Maintenance & incremental development ´
6 Health & comfort +
7 Enduring safety & performance ´
8Standardization, quality control, pace -
9 Continuous innovation
10 Cost advantage of houses +
11 Scalable business model
12 Supply accessibility +
13 Supply availability & sustainability
14 Environmental impact
15 Compliance to policies & regulations
Figure 3. Sustainability Criteria elicited from local practices with bamboo.
The below narrative case description describes the findings in detail:
-
As per today, buildings using bamboo are based on traditional practices and designs relying on
orally transferred skills of local builders. However, a change in building practice was noticed
towards conventional technologies. This causes lesser builders to transfer their skills to next
generations, which makes bamboo construction less likely an additional source of income. The
latter is critical, since only few inhabitants have skills in maintaining a raw material sourced
from the countryside. The development of skills and livelihood opportunities through bamboo
craftsmanship were highlighted to be relevant criteria expressed during the field study with the
rural population and local builders.
-
The field study extracted that conventional concrete and steel houses are considered more modern,
safer, and less maintenance intensive. The social acceptance of a building method is also largely
connected to a contemporary house design. Statistics and survey have shown that the highest
share of today’s bamboo users belong to low-income groups who experience shortcomings
tapping into more commercial options. The utilization of the material is therefore perceived
equivalent to being poor.
-
Interviews with inhabitants reveal that a comfortable living climate is a frequently mentioned
positive aspect. This said, it is noted, that the definition of “comfort” in the tropical climate of the
Philippines has to be classified context specific.
-
Statistical information of the Philippine Government revealed that inhabitants living in the
traditional lightweight bamboo houses are not ensured of basic safety during natural disasters,
especially typhoons [
8
]. Next to interviews with Government experts, the correlation between
vulnerability and bamboo housing has been documented in several post-disaster damage
assessment reports after typhoon Haiyan in 2013. Among others, this can be ascribed to temporary
connections between the bamboo elements, which not maintained, often underutilize the potential
of the raw material as fail as weakest component of the system. As a result, the preferences
of people towards conventional technologies, which are considered as more safe, gain further
speed. An improved technical performance of bamboo-based houses in compliance with technical
minimum standards for disaster resistance is considered as Sustainability Assessment Criterion.
-
The abundant availability of bamboo made it ever since an affordable raw material for
construction across the archipelago. Cost savings compared to conventional solutions were
named a key incentive for using the material.
Sustainability 2016,8, 151 11 of 26
-
Bamboo houses are mostly found in rural communities living nearby bamboo sources, where its
craftsmanship provides a valuable source of income next to farming. Since every builder uses
bamboo only for a few houses, no shortcomings of supply were noticed.
In summary, the field survey and expert interviews reveal that none-standardized bamboo houses
are mainly used because of economic aspects. However, they have never undergone a technical
development responding to the requirements of a more urban and disaster prone context. As
a result, the potential to apply bamboo as load bearing material for house construction in the urban
Philippines remains untapped until a building concept can respond to comply with technical and
social requirements.
3.1.2. Findings from Case Studies Using Forest Products for Housing around the Globe
Case studies from other regions provided qualitative data on barriers and opportunities to use
forest products for housing. Two selected cases have been studied: (A) Bamboo construction in Latin
America and (B) Timber frame construction in Europe. The coded and sorted data led to seven criteria
from case (A) and 11 criteria from case (B), which partially overlapped with one exception. In total
12 criteria were elicited, as shown below in Figure 4:
SUSTAINABILITY ASSESSMENT CRITERIA
No. Pillar of Sustainability Criteria Case
Society
Technology
Economy
Ecology
Governance
(2A) (2B)
1 Social acceptance & advocacy ˘+
2 Participation & identification
3 Capacity building + +
4 Income at local value chain
5 Maintenance & incremental development
6 Health & comfort +
7 Enduring safety & performance + +
8Standardization, quality control, pace +
9 Continuous innovation + +
10 Cost advantage of houses +
11 Scalable business model +
12 Supply accessibility +
13 Supply availability & sustainability + +
14 Environmental impact +
15 Compliance to policies & regulations + +
Figure 4. Sustainability Criteria elicited from global case studies of using forest products.
Six of the eight criteria, extracted from the data about Philippines bamboo utilization, can also be
found in the two global cases. The below narrative description is a cross-pattern analysis describing
the findings in detail:
(A) Bamboo construction in Latin America:
-
In several countries of Latin America, the indigenous population used to live in houses made
from bamboo. During the colonial time, European technologies started to influence traditional
practices. This was the beginning of the construction technique locally named “Bahareque”:
a combination of the original bamboo frame system with cement plaster cladding and an
evolvement of skill and capacity. Bahareque spread as success story in Colombia, Ecuador and
Peru as a confluence of traditional and new materials and practices. Especially the Coffee Belt
Region of Colombia substantial parts of the houses, up to 50 percent, have been built with this
construction method in the past 200 years. Similarly to the Asian case, this development was
motivated by the high availability of bamboo.
-
Further, empiric evidence showed its good response to earthquakes compared to the
non-reinforced adobe systems utilized in the area during those days. Due to a high seismic
activity in the Colombian Coffee Belt, the system was tested during several seismic shocks. An
Sustainability 2016,8, 151 12 of 26
earthquake with strongly destructive impact took place in 1999. The event of magnitude 6.2 on
Richter scale had a shallow depth of 6 km and an epicenter of only 20 km away from major cities,
leading to the death of more than 1600 people. Despite the destructive power of the natural
disaster, it was remarkable that more than 90 percent of the causalities occurred in non-bamboo
structures. Post-impact studies showed that the causalities in or near bamboo houses occurred
only due to deterioration of the structural elements or debris from heavy materials destroying
the lighter bamboo structures. Therefore, the Association of Structural Engineers in Colombia
(AIS) started to study the characteristic behavior of the construction method.
-
The idea to standardize and develop a building code for capturing the design rules of this
construction type arose, which lead again to several improvements of the construction method.
From the year 2000 onwards, tests were carried out in Colombia on the mechanical properties of
the local bamboo, called Guadua Angustifolia, according to a preliminary draft of ISO 22157,
which was published four years later under the name Bamboo—Determination of physical and
mechanical properties [
52
,
53
]. Further tests were conducted on frame wall systems and on full-scale
buildings to determine its resistance to seismic impacts. The results of these investigations were
the basis for the building code, which was published in 2002 and is known today as Colombian
Building Code- Section E: Design and Construction of Houses of one and two stories with plastered
Bahareque [54].
-
The remarkable technical development, which took place in Latin America, contributed to several
extraordinary, globally rewarded structures such as in [
55
], which changed the paradigm from a
material for the poor to an ecologically valued, high performance material for wealthy customers.
-
While this is a considerable track record, the Colombian development has not entered into a
large scale application of the building concept, despite the existence of research and regulations.
Structures are however implemented on a project basis, and no institutions exist providing
affordable construction and after sales services for a large number of cost-efficient houses. Only
a few recent social housing projects exist, where it was noted during the field study in Colombia,
that the needs and requirements of civil society customers have hardly been considered in
the design. A lack of ownership and identification of inhabitants in social housing projects
was identified.
-
As second main barrier for Latin American bamboo construction to scale are the regulatory
barriers in supplying bamboo. Being declared as forest product, special permits are required
despite its availability.
The case of Asia has analogies to the Latin American history and is yet to be looked at regionally
and country specific. While bamboo is also an available raw material in many countries of the
Asia-Pacific, its utilization in round shape has hardly evolved. In countries like China and Vietnam,
the bamboo serves mainly as raw material for industrially produced laminated products [
50
]. Target
markets are pre-dominantly for Western or higher income local customers. In the Philippines, same as
with other countries in Asia, the need for urban housing was never combined with the potential of
using the local raw material. While the existing local practice was not responding to the needs of urban
stakeholders for housing, there was hardly any scientific technical development taking place or, if so,
it was not connected to application projects. In Latin America, the strong disaster performance during
earthquake impacts has boosted its acceptance among civil society. Since the Philippines encounter
earthquakes and typhoons, the technology has to perform against multi-hazards reliably. Lastly, the
cases from Latin America highlight that, excluding luxury resorts, a lacking ownership and identity
of lower income groups towards living in bamboo-based houses is a bottleneck. The relevance of
participation and involvement is highlighted as a criterion for market acceptance and the active stake
of low-income groups is a crucial criterion. A technical transfer and South-South sharing of experiences
was found to considerably speed-up the Asian development by bringing in technical knowhow in
complementation to the conceptual framework of Asia.
Sustainability 2016,8, 151 13 of 26
(B) Timber frame construction in Europe
As a second case study, the development of timber frame construction systems in Europe
was assessed.
-
In Europe, wood is increasingly used in housing, schools, administrative, cultural, and exhibition
buildings, halls and factories, as well as in bridges, sound barriers, hydraulic engineering and
avalanche control. Its social acceptance varies per country in the EU, but several examples
exist where the population adopted it as modern building material with a major share of
built environment.
-
One driver for this development is a growing market of stakeholders emphasizing ecological
concerns. Timber structures are related with CO
2
sequestration, being a renewable raw material,
producing little construction waste, and requiring low energy for processing. In South Europe,
the use of wood is becoming synonym of energy efficient building.
-
Moreover, the highest levels of indoor comfort can be obtained with timber structures, which
however requires a combination with further building materials.
-
Timber engineering is commonly lectured in academe education, which reduces barriers of
professionals to train capacity and apply the building material later on.
-
The flexibility of lightweight modular timber construction is particularly suited because of its
adaptability and pace in construction. Driver for continuous innovation are industrial business
models reducing cost per square meter. Industrialized manufacturing methods on a high
prefabrication level have significantly advanced building with wood and opened markets for
the sector, especially on an urban scale.
-
Several European governments are currently deploying programs on building with wood. Two
additional building applications are identified as potential markets: multi-story large volume
new buildings, as well as retrofitting using timber based solutions. Both have been successfully
realized and are now on the way to up scaling, in Europe.
-
In order for innovative wood-based building methods to be approved on the European market,
the European Technical Approval scheme has to be considered [
56
]. For decades, the fire
resistance resulted in a barrier of timber construction for multi-story buildings [
57
], while once
technically solved, it opened the market for more applications. Compliance with rules and
regulations, ensuring a durable technical performance, is however a must for an application in
the EU.
-
However, building with wood sector faces a growing intrusive environment of legal frameworks,
critical public perception as well as a rising economical threat which is becoming a barrier to a
successful future economic development of the wood industry.
- Supply availability & sustainability: regional scale, approval schemes.
3.1.3. Learnings from Stakeholder Requirements in Social Housing of the Philippines
In 30 semi-structured interviews, clustered into five stakeholder-sub-groups, requirements in
Philippine social housing in general and implementing the alternative building technology specifically
were captured. Obtained barriers and opportunities were sorted, condensed, and clustered. The
evaluation has returned the most comprehensive set of criteria. While common themes from the
other cases were found, also one critical criterion was added: participation & identification. The
comprehensiveness of criteria displays the complexity of social housing. Below, in Figure 5, all
identified criteria are summarized:
Sustainability 2016,8, 151 14 of 26
SUSTAINABILITY ASSESSMENT CRITERIA
No. Pillar of Sustainability Criteria (3)
Society
Technology
Economy
Ecology
Governance
1 Social acceptance & advocacy +
2 Participation & identification +
3 Capacity building +
4 Income at local value chain +
5 Maintenance & incremental development +
6 Health & comfort +
7 Enduring safety & performance +
8Standardization, quality control, pace +
9 Continuous innovation +
10 Cost advantage of houses +
11 Scalable business model +
12 Supply accessibility +
13 Supply availability & sustainability +
14 Environmental impact +
15 Compliance to policies & regulations +
Figure 5. Sustainability Criteria elicited from stakeholders involved in social housing.
The below narrative case description describes the findings in detail:
-
Lower initial construction costs were mentioned as major incentive to consider alternative
building methods across all stakeholder groups, since latter will allow more people to access
adequate housing. Economic advantages are therefore an important entry point for system change,
however, not the only requirement for an innovation to succeed on the social housing market.
-
Facilitating regulations and a legal approval of the building technology on national or even
regional or global scale are needed for a technology spread. Since, however, the alternative
building technology is not covered by existing building codes, but restricted by general
requirement in force; compliance to such and design rules for it have to be developed.
Little enforcement of minimum structural performance requirements in social housing make
substandard practices likely and might slow down the spread of a performing technology.
-
Showcasing the technology at full scale, for example through demonstration units, as well as
national, regional, and global best practice sharing and advocacy, have been mentioned to be
needed for assessing customer acceptance. Customer acceptance and first positive sales results
are promising from the current start-up operations in the Philippines. It is acknowledged, though,
that this acceptance is driven to large parts by the urgency of an underserved market and the
need for more adequate housing, which the technology provides a good solution for.
-
The interviews revealed that the value chain is an important criterion, which can create local
impact from cradle-to-grave: from resource planting up to the demolition of houses built with
it. Relevant barriers and risks for an application at scale, though, are also caused by this value
chain. Existing bamboo supply chains have to be adjusted and scaled according to the needs of
the technology.
-
Critically mentioned were further the material availability and long term sustainability of bamboo
supply, which will influence the pace and dimension of a technology scale-up. Both, market-prices
for bamboo and quality grading have to be established for affordable, performing construction.
Training on sustainable harvesting of bamboo has to fall in line with a logistic concept for accessing
the resources and bringing it to the processing sites. It is predicted that increasing harvesting
yield and efficiency is a time intensive process. Involvement and strengthening networks of
existing bamboo suppliers is deemed important for immediate supply. It was mentioned as an
asset, that the value chain can create rural-urban linkages combining two governmental targets:
Rural farmers receiving livelihood opportunities through material supply and urban poor being
clients for housing. The factors pace of scale-up and absolute scale intended are crucial for
a strategy definition. The ecological impact reduction through utilization of renewable, available
raw materials creates policy incentives for the government, which can mobilize multi-stakeholder
involvement for the needed supply and construction related capacity building. The environmental
impact has to be proven transparently.
Sustainability 2016,8, 151 15 of 26
-
Cross-cutting through all six stakeholder clusters is the trajectory of capacity building: continuous
skills development for stable minimum quality insurance is a requirement, both in supply as well
as construction. This is a sensitive process, where local practices and learnings from global sharing
have to be merged culturally sensitive. It involves all levels of stakeholders, from low-skilled to
skilled workers and academe.
-
The interviewed stakeholders highlighted that investing into a residential home is a long term
commitment for most people. A new building practice causes customers and loan providers to
hesitate taking the risk. Due to the disaster prone context of the Philippines, a reliable technical
performance ensuring people’s safety has been mentioned as important. A comprehensive
technical development is the basis for such a reliability and durability enabling trust. As seen
in the case of Colombia, a convincing system performance will create a track record for the
technology. During interviews with stakeholders involved in the technology development,
this knowledge has resulted in solid trust into the technology. The South-South sharing has
increased speed of gaining such a knowledge basis. Besides disaster resistance, stakeholders
from low-income groups expressed their strong desire to obtain durable houses causing little
maintenance efforts. To be highlighted is also the relevance of a strong quality control concept
ensuring a stable technical performance in implementation projects.
-
A continuous process of optimization and innovation in prefabrication and construction will
increase the speed of construction, decrease the level of skills needed, and strengthen the
scalability of the approach.
-
It was underlined both by potential clients and facilitators, that incremental expansion and
upgrading along with societal development is common reality and should be enabled.
-
Inclusion of low income groups is a pathway to success, since conventional modes of house
provision are mostly not affordable and do not consider the factor of ownership. The
participatory process gives consideration to the concerns of clients in planning, construction and
post-occupation.
3.1.4. Sustainability Assessment Criteria
In summary, 15 partially interlinked Sustainability Assessment Criteria were derived from the
findings through literature review, field survey and interviews with the three fields: (1) Builders and
users of traditional bamboo houses, (2A) Stakeholders using bamboo for housing in Latin America or
(2B) timber for housing in Europe, and (3) Stakeholders in the field of social housing in the Philippines.
Figure 6below summarizes all mentioned requirements, using the symbol allocation process described
in the Method section.
SUSTAINABILITY ASSESSMENT CRITERIA
No. Pillar of Sustainability Criteria Case
Society
Technology
Economy
Ecology
Governance (1) (2A) (2B)
(3)
1 Social acceptance & advocacy -˘++
2 Participation & identification +
3 Capacity building -+ + +
4 Income at local value chain + +
5 Maintenance & incremental development - +
6 Health & comfort +++
7 Enduring safety & performance -+ + +
8Standardization, quality control, pace -++
9 Continuous innovation + + +
10 Cost advantage of houses +++
11 Scalable business model + +
12 Supply accessibility +++
13 Supply availability & sustainability + + +
14 Environmental impact + +
15 Compliance to policies & regulations + + +
Figure 6. Summary of Sustainability Assessment Criteria.
Sustainability 2016,8, 151 16 of 26
The stated Sustainability Assessment Criteria are multi-dimensional covering the pillars society,
economy, ecology, technology, and governance. The stakeholder interviews in the field of social
housing have resulted in the most comprehensive set of criteria, while the stakeholder assessment (1),
(2a), and (2b) have underpinned specific sub-sets of it.
3.2. Strategic Technology Development Roadmap
This section documents the roadmap which, once implemented, will enabling a Holistic
Performance Assessment in a Multi-Criteria Development Process. Within the four implementation
strategies, (1) Research about -, and (2) Implementation of the building technology, (3) Participation
& Capacity Building and (4) Sustainable Supply Chain, 28 action items for data generation were
identified. The methods for data generation in these 28 action items were specified according to
scientific requirements and context related suitability. The sum of all action items covers a cradle to
grave life cycle of the product: whether within a respective action item, such as Life Cycle Assessment
quantifying environmental performance, or whether through the consecutive alignment of various
action items after each other, such as supply, followed by construction, use phase of the house and
its end of life. The methods suggested for data generated in the individual endpoints will provide
transparency on individual aspects of sustainability. In the following, the 28 action items are presented
alongside of the methods for data generation:
(1)
The Research Strategy was segmented in research topics on material, system, and building
scales, as visualized in Figure 7. Data generated in these three dimensions enables to understand
and control the technical performance, and with that contribute to social acceptance through
compliance with urban policies. The action items cover all pillars of sustainability and are
summarized in Figure 8. For a sustainable urban development, the complex settlement scale
would also require consideration. Latter is however hardly tied to a specific construction method
and is therefore not part of this technology-related roadmap.
Sustainability2016,8,15116of25
(1) TheResearchStrategywassegmentedinresearchtopicsonmaterial,system,andbuilding
scales,asvisualizedinFigure7.Datageneratedinthesethreedimensionsenablestounderstand
andcontrolthetechnicalperformance,andwiththatcontributetosocialacceptancethrough
compliancewithurbanpolicies.Theactionitemscoverallpillarsofsustainabilityandare
summarizedinFigure8.Forasustainableurbandevelopment,thecomplexsettlementscale
wouldalsorequireconsideration.Latterishoweverhardlytiedtoaspecificconstructionmethod
andisthereforenotpartofthistechnologyrelatedroadmap.
Figure7.ComprehensiveresearchfromMaterial,overSystem,toBuildingScale.
MaterialScale:Researchcontainsselectionandstrengthgradingofbamboospecies,which
ensuresTechnicalPerformance,CostAdvantage,andSustainableSupply.Throughfieldand
literaturestudypotentialspeciescanbeidentified.Similartothefieldoftimberengineering,a
strengthgradingofbambooculmshasbeencarriedouttounderstandthematerialcharacteristics
andpossiblemethodsofutilization.Sincenointernationalstandardonbamboostrengthgrading
exists,theauthorsdefinebiologic,geometricandmechanicalcharacteristics.Theresultsguide
engineersinthestructuraldesignofhouses.
SystemScale:Inordertomaximizetherawmaterialstrengthaswellastocopewithits
weaknesses,criticalelementsforTechnicalPerformancearestructuralConnections,whichexistfrom
thefoundationtowallandwalltoroof.ConnectionshavetobedevelopedalsoaccordingtotheCost
AdvantagecriterionaswellastheMaintenanceone.Thesystemscaletestingwasshapedfurtherby
thecriteriaSkillDemand,Modularization,andImplementationPace.Further,theresistanceofthe
buildingsystemtofireandlateralforces,asinducedduringearthquakesandstrongwinds,hasbeen
testedonsystemleveltoensuredurableperformance.
BuildingScale:BuildingScalecontainstestingthebuildingresponseonthreedimensionalmodel
houses.InfullscaleTyphoonTests,thepredictedlaboratoryperformancehastobeconfirmedunder
reallifeconditions.Further,theThermalComfortduringdaytodayperformanceistested,as
mentionedinthesurveystobeanimportantcriterion.Transparentlyevaluatingtheenvironmental
impactofthestructurecomparedtoconventionalsolutionsiscapturedinLifeCycleImpact
Assessment.Allresultsonmaterial,system,andbuildingscalesfinallyleadtowardstheabilityofa
legalapprovalasbuildingconceptinthePhilippines.Onbuildingscale,finallyalsotheeconomic
criteriahavefoundconsiderationthroughmeasuringeconomicindicators.
Foreachoftheresearchtopics,specificonedimensionalquantitativetestingmethodsare
identifiedtogeneratedatawithscientificvalidityaswellaslocalandfinancialapplicabilityforthe
givencontext.Bothlaboratoryandfieldtestsareincluded.Fullreferencetothetestingstandards
namedisgivenintheliteraturelist[52,53,58–64].
Figure 7. Comprehensive research from Material, over System, to Building Scale.
Material-Scale: Research contains selection and strength grading of bamboo species, which ensures
Technical Performance, Cost Advantage, and Sustainable Supply. Through field and literature study
potential species can be identified. Similar to the field of timber engineering, a strength grading of
bamboo culms has been carried out to understand the material characteristics and possible methods
of utilization. Since no international standard on bamboo strength grading exists, the authors define
biologic, geometric and mechanical characteristics. The results guide engineers in the structural design
of houses.
Sustainability 2016,8, 151 17 of 26
System-Scale: In order to maximize the raw material strength as well as to cope with its weaknesses,
critical elements for Technical Performance are structural Connections, which exist from the foundation
to wall and wall to roof. Connections have to be developed also according to the Cost Advantage
criterion as well as the Maintenance one. The system scale testing was shaped further by the criteria
Skill Demand, Modularization, and Implementation Pace. Further, the resistance of the building
system to fire and lateral forces, as induced during earthquakes and strong winds, has been tested on
system level to ensure durable performance.
Building-Scale: Building-Scale contains testing the building response on three-dimensional model
houses. In full scale Typhoon Tests, the predicted laboratory performance has to be confirmed under
real life conditions. Further, the Thermal Comfort during day to day performance is tested, as
mentioned in the surveys to be an important criterion. Transparently evaluating the environmental
impact of the structure compared to conventional solutions is captured in Life Cycle Impact Assessment.
All results on material, system, and building scales finally lead towards the ability of a legal approval
as building concept in the Philippines. On building scale, finally also the economic criteria have found
consideration through measuring economic indicators.
For each of the research topics, specific one-dimensional quantitative testing methods are
identified to generate data with scientific validity as well as local and financial applicability for
the given context. Both laboratory and field tests are included. Full reference to the testing standards
named is given in the literature list [52,53,5864].
Sustainability2016,8,15117of25
Figure8.Systemicapproachonresearchaboutbuildingconcept.
SelectedinitialresultsprovideinsightsaboutcharacteristicstrengthsinCompression(f
c,o,k
=20
MPa),Tension(f
t,o,k
=95MPa),Shear(f
v,k
=5MPa)andBending(f
m,k
=34.6MPa)aswellasaModulus
ofElasticityMOEat5thpercentile(E
0.05
=8600MPa),testedaccordingto[52].Therecommended
shearwallrakingstrength,determinedaccordingto[63],wasfoundtobe8kN/mforwallscladded
frombothsides.Afireratingof60minresistanceaccordingto[65]andcompliancetolocal
regulationsforseismicandwindforcesaccordingto[66]wasobtained.Theenvironmentalimpact
assessmentaccordingto[62]showeda60%reductionofCO
2
emissionscomparedtotheconventional
concretebuilding.Inathermalcomfortassessment,ahealthyindoorclimatewasdetermineddueto
aclimateadjustedhousedesignandthechoiceofthebuildingmaterial[61,67].Instudiesaboutthe
resistanceofthehousesduringreallifetyphoonimpactssince2012,thehouseswithstoodinnerand
outerwindbandsoffivetyphoonsrangingfrom140to180kph,includingtwicebeinghitbytheeye
oftyphoonsduringthreetyphoonseasons.Nostructuraldamagewasobservedduringandafter
theseextremeimpacts,whichconfirmsthecalculatedstructuralperformanceaccordingto[68].The
combinationofallofaboveresultsenableanapplicationfornationwidelegalapprovalinthe
Philippinessuchas[59]or[69].
(2) Theresearchstrategyiscomplementedwithaparallel,slightlytimeshiftedimplementation
strategy,whichcontainsselectedimplementationactions.LattercoverthepillarsTechnology,
SocietyandEconomy.With7ofthe15SustainabilityCriteria,animplementationstrategyat
scaleandrobustqualityisshaped:QualityControlforrobusttechnicalperformance,Easeof
ApplicationandSkillDevelopment,Constructionspeedandscalability,Innovationthrough
participationandevaluationofpracticabilityofconcepts,asdisplayedinFigure9.Finally,
previouslytheoreticalEconomicIndicatorswereverifiedthroughimplementationprojects.It
canbenoted,thatallcriteriawerealreadyconsideredintheSystemScaleandBuildingScale
researchstrategyandarenowverifiedthroughapplicationinthefield.In2012,six
demonstrationhouseswerebuilt,sincethenanother150houseshavebeenimplemented[46].
Figure9.Continuousoptimizationcriteriaoftechnologyimplementation.
Figure 8. Systemic approach on research about building concept.
Selected initial results provide insights about characteristic strengths in Compression (fc,o,k = 20 MPa),
Tension (f
t,o,k
= 95 MPa), Shear (f
v,k
= 5 MPa) and Bending (f
m,k
= 34.6 MPa) as well as a Modulus of
Elasticity MOE at 5th percentile (E
0.05
= 8600 MPa), tested according to [
52
]. The recommended shear
wall raking strength, determined according to [
63
], was found to be 8 kN/m for walls cladded from
both sides. A fire rating of 60 min resistance according to [
65
] and compliance to local regulations
for seismic and wind forces according to [
66
] was obtained. The environmental impact assessment
according to [
62
] showed a 60% reduction of CO
2
emissions compared to the conventional concrete
building. In a thermal comfort assessment, a healthy indoor climate was determined due to a climate
adjusted house design and the choice of the building material [
61
,
67
]. In studies about the resistance
of the houses during real-life typhoon impacts since 2012, the houses withstood inner and outer wind
bands of five typhoons ranging from 140 to 180 kph, including twice being hit by the eye of typhoons
during three typhoon seasons. No structural damage was observed during and after these extreme
impacts, which confirms the calculated structural performance according to [
68
]. The combination of
all of above results enable an application for nationwide legal approval in the Philippines such as [
59
]
or [69].
Sustainability 2016,8, 151 18 of 26
(2)
The research strategy is complemented with a parallel, slightly time shifted implementation
strategy, which contains selected implementation actions. Latter cover the pillars Technology,
Society and Economy. With 7 of the 15 Sustainability Criteria, an implementation strategy at
scale and robust quality is shaped: Quality Control for robust technical performance, Ease of
Application and Skill Development, Construction speed and scalability, Innovation through
participation and evaluation of practicability of concepts, as displayed in Figure 9. Finally,
previously theoretical Economic Indicators were verified through implementation projects.
It can be noted, that all criteria were already considered in the System Scale and Building Scale
research strategy and are now verified through application in the field. In 2012, six demonstration
houses were built, since then another 150 houses have been implemented [46].
Sustainability2016,8,15117of25
Figure8.Systemicapproachonresearchaboutbuildingconcept.
SelectedinitialresultsprovideinsightsaboutcharacteristicstrengthsinCompression(f
c,o,k
=20
MPa),Tension(f
t,o,k
=95MPa),Shear(f
v,k
=5MPa)andBending(f
m,k
=34.6MPa)aswellasaModulus
ofElasticityMOEat5thpercentile(E
0.05
=8600MPa),testedaccordingto[52].Therecommended
shearwallrakingstrength,determinedaccordingto[63],wasfoundtobe8kN/mforwallscladded
frombothsides.Afireratingof60minresistanceaccordingto[65]andcompliancetolocal
regulationsforseismicandwindforcesaccordingto[66]wasobtained.Theenvironmentalimpact
assessmentaccordingto[62]showeda60%reductionofCO
2
emissionscomparedtotheconventional
concretebuilding.Inathermalcomfortassessment,ahealthyindoorclimatewasdetermineddueto
aclimateadjustedhousedesignandthechoiceofthebuildingmaterial[61,67].Instudiesaboutthe
resistanceofthehousesduringreallifetyphoonimpactssince2012,thehouseswithstoodinnerand
outerwindbandsoffivetyphoonsrangingfrom140to180kph,includingtwicebeinghitbytheeye
oftyphoonsduringthreetyphoonseasons.Nostructuraldamagewasobservedduringandafter
theseextremeimpacts,whichconfirmsthecalculatedstructuralperformanceaccordingto[68].The
combinationofallofaboveresultsenableanapplicationfornationwidelegalapprovalinthe
Philippinessuchas[59]or[69].
(2) Theresearchstrategyiscomplementedwithaparallel,slightlytimeshiftedimplementation
strategy,whichcontainsselectedimplementationactions.LattercoverthepillarsTechnology,
SocietyandEconomy.With7ofthe15SustainabilityCriteria,animplementationstrategyat
scaleandrobustqualityisshaped:QualityControlforrobusttechnicalperformance,Easeof
ApplicationandSkillDevelopment,Constructionspeedandscalability,Innovationthrough
participationandevaluationofpracticabilityofconcepts,asdisplayedinFigure9.Finally,
previouslytheoreticalEconomicIndicatorswereverifiedthroughimplementationprojects.It
canbenoted,thatallcriteriawerealreadyconsideredintheSystemScaleandBuildingScale
researchstrategyandarenowverifiedthroughapplicationinthefield.In2012,six
demonstrationhouseswerebuilt,sincethenanother150houseshavebeenimplemented[46].
Figure9.Continuousoptimizationcriteriaoftechnologyimplementation.
Figure 9. Continuous optimization criteria of technology implementation.
For the application in the given context, the concept of Prefabrication was chosen. It stands
in contrast to the traditional construction practices, where individual skilled community builders
guide teams to a performing result. Latter is the dominating method in the bamboo sector, both in
the Philippines and around the globe. Prefabrication is a well-established concept for light weight
construction with timber in Europe and has been applied on pilot scale with bamboo in Latin America.
While both concepts have their justification, the Sustainability Criteria highlight the relevance of
scalability, quality control and cost-efficiency. Prefabrication facilitates a quality-controlled production
of load bearing elements and increases the pace of construction of construction projects. Given the
climatic context of the Philippines, with immense sunshine and strong seasonal rainfalls or winds, it is
of value to reduce construction time to a minimum and with that exposure of humans to the elements.
Below Figure 10 provides an example of a pre-fabricated bamboo frame house with the assembled
load bearing structure on the left, one prefabricated frame in the middle in two stages of finishing and
a fully finished house on the right side.
Sustainability2016,8,15118of25
Fortheapplicationinthegivencontext,theconceptofPrefabricationwaschosen.Itstandsin
contrasttothetraditionalconstructionpractices,whereindividualskilledcommunitybuildersguide
teamstoaperformingresult.Latteristhedominatingmethodinthebamboosector,bothinthe
Philippinesandaroundtheglobe.Prefabricationisawellestablishedconceptforlightweight
constructionwithtimberinEuropeandhasbeenappliedonpilotscalewithbambooinLatin
America.Whilebothconceptshavetheirjustification,theSustainabilityCriteriahighlightthe
relevanceofscalability,qualitycontrolandcostefficiency.Prefabricationfacilitatesaquality
controlledproductionofloadbearingelementsandincreasesthepaceofconstructionofconstruction
projects.GiventheclimaticcontextofthePhilippines,withimmensesunshineandstrongseasonal
rainfallsorwinds,itisofvaluetoreduceconstructiontimetoaminimumandwiththatexposureof
humanstotheelements.BelowFigure10providesanexampleofaprefabricatedbambooframe
housewiththeassembledloadbearingstructureontheleft,oneprefabricatedframeinthemiddlein
twostagesoffinishingandafullyfinishedhouseontherightside.
Figure10.ModernbamboobasedhousingbuiltinIloilo,RegionIVin2015by[46,49].
Nexttothecriteriareliablequalityandpaceonconstructionsite,easeofconstruction,aswellas
neededskillshavebeenimportantelementsfortheiterativeoptimizationprocess.Theconstruction
withprefabricatedframesreducestheskillsneededonconstructionsiteandtransfersthemintothe
productionhall,wherecapacitycanbebuiltfor.Expandingskillsofbamboocraftsmencontributes
topreservingselectedtraditionalskills,whiletransformingthemwhereneededtoarecognized
knowhowoftoday`sindustry.Theuseofconventionalmortarfinishingcoveringthebamboobased
frameisimportantforanenduringtechnicalperformance,fireandtyphoonresistance,usercomfort,andlow
maintenanceneeds.InreferencetotheidentifiedaftersalesservicegapinColombia,easilyavailable
technicalsupportforpostoccupationserviceswasdeemedimportant.
Figure11summarizestheidentifiedonedimensionalimplementationactionsandmethodsfor
datageneration.Comparedtotheresearchstrategy,theimplementationstrategycontainsboth
quantitativemethods,suchastheoneforstructuraldesignofhouses,aswellasqualitativemethods
suchastrainings,qualitycontrolconcepts,participatoryconsultations,andaninnovationenabling
environment.Referenceisgiventothesuggestedmethodsintheliteraturelist[54,66,68].
Figure11.Systemicapproachonimplementationofbuildingconcept.
Figure 10. Modern bamboo-based housing built in Iloilo, Region IV in 2015 by [46,49].
Next to the criteria reliable quality and pace on construction site, ease of construction, as well as
needed skills have been important elements for the iterative optimization process. The construction
with prefabricated frames reduces the skills needed on construction site and transfers them into the
Sustainability 2016,8, 151 19 of 26
production hall, where capacity can be built for. Expanding skills of bamboo craftsmen contributes
to preserving selected traditional skills, while transforming them where needed to a recognized
knowhow of today‘s industry. The use of conventional mortar finishing covering the bamboo-based
frame is important for an enduring technical performance, fire and typhoon resistance, user-comfort, and low
maintenance needs. In reference to the identified after-sales service gap in Colombia, easily available
technical support for post-occupation services was deemed important.
Figure 11 summarizes the identified one-dimensional implementation actions and methods
for data generation. Compared to the research strategy, the implementation strategy contains both
quantitative methods, such as the one for structural design of houses, as well as qualitative methods
such as trainings, quality control concepts, participatory consultations, and an innovation enabling
environment. Reference is given to the suggested methods in the literature list [54,66,68].
Sustainability2016,8,15118of25
Fortheapplicationinthegivencontext,theconceptofPrefabricationwaschosen.Itstandsin
contrasttothetraditionalconstructionpractices,whereindividualskilledcommunitybuildersguide
teamstoaperformingresult.Latteristhedominatingmethodinthebamboosector,bothinthe
Philippinesandaroundtheglobe.Prefabricationisawellestablishedconceptforlightweight
constructionwithtimberinEuropeandhasbeenappliedonpilotscalewithbambooinLatin
America.Whilebothconceptshavetheirjustification,theSustainabilityCriteriahighlightthe
relevanceofscalability,qualitycontrolandcostefficiency.Prefabricationfacilitatesaquality
controlledproductionofloadbearingelementsandincreasesthepaceofconstructionofconstruction
projects.GiventheclimaticcontextofthePhilippines,withimmensesunshineandstrongseasonal
rainfallsorwinds,itisofvaluetoreduceconstructiontimetoaminimumandwiththatexposureof
humanstotheelements.BelowFigure10providesanexampleofaprefabricatedbambooframe
housewiththeassembledloadbearingstructureontheleft,oneprefabricatedframeinthemiddlein
twostagesoffinishingandafullyfinishedhouseontherightside.
Figure10.ModernbamboobasedhousingbuiltinIloilo,RegionIVin2015by[46,49].
Nexttothecriteriareliablequalityandpaceonconstructionsite,easeofconstruction,aswellas
neededskillshavebeenimportantelementsfortheiterativeoptimizationprocess.Theconstruction
withprefabricatedframesreducestheskillsneededonconstructionsiteandtransfersthemintothe
productionhall,wherecapacitycanbebuiltfor.Expandingskillsofbamboocraftsmencontributes
topreservingselectedtraditionalskills,whiletransformingthemwhereneededtoarecognized
knowhowoftoday`sindustry.Theuseofconventionalmortarfinishingcoveringthebamboobased
frameisimportantforanenduringtechnicalperformance,fireandtyphoonresistance,usercomfort,andlow
maintenanceneeds.InreferencetotheidentifiedaftersalesservicegapinColombia,easilyavailable
technicalsupportforpostoccupationserviceswasdeemedimportant.
Figure11summarizestheidentifiedonedimensionalimplementationactionsandmethodsfor
datageneration.Comparedtotheresearchstrategy,theimplementationstrategycontainsboth
quantitativemethods,suchastheoneforstructuraldesignofhouses,aswellasqualitativemethods
suchastrainings,qualitycontrolconcepts,participatoryconsultations,andaninnovationenabling
environment.Referenceisgiventothesuggestedmethodsintheliteraturelist[54,66,68].
Figure11.Systemicapproachonimplementationofbuildingconcept.
Figure 11. Systemic approach on implementation of building concept.
(3)
Stakeholder participation, capacity building and a close interaction between low-income groups,
professionals, governments and further stakeholder groups was reflected through a strategy on
stakeholder involvement, displayed in Figure 12. The participatory process gives consideration
to the need and concerns of low-income groups in planning, construction, and post-occupation.
The strategy describes where and how participation and capacity building has been integrated in
the technology development. Continuous process simplifications and parallel skill development
facilitate involvement of people. Post occupational customer acceptance testing according to
corporate standards allow to identify further innovation potentials and are therefore connected
to the area ‘innovation’ in the implementation roadmap. Policy approval and expansion has
been targeted through national, regional and global best practice sharing and advocacy and is
connected to the area of legal approval under research.
Sustainability2016,8,15119of25
(3) Stakeholderparticipation,capacitybuildingandacloseinteractionbetweenlowincomegroups,
professionals,governmentsandfurtherstakeholdergroupswasreflectedthroughastrategyon
stakeholderinvolvement,displayedinFigure12.Theparticipatoryprocessgivesconsideration
totheneedandconcernsoflowincomegroupsinplanning,construction,andpostoccupation.
Thestrategydescribeswhereandhowparticipationandcapacitybuildinghasbeenintegrated
inthetechnologydevelopment.Continuousprocesssimplificationsandparallelskill
developmentfacilitateinvolvementofpeople.Postoccupationalcustomeracceptancetesting
accordingtocorporatestandardsallowtoidentifyfurtherinnovationpotentialsandare
thereforeconnectedtothearea‘innovation’intheimplementationroadmap.Policyapproval
andexpansionhasbeentargetedthroughnational,regionalandglobalbestpracticesharingand
advocacyandisconnectedtotheareaoflegalapprovalunderresearch.
Figure12.Systemicapproachonintegratingofstakeholderrequirements.
(4) Further,thetechnologyapplicationatlargerscalerequiresasustainablygenerated,accessible
supplyofqualitygradedbamboo.Bamboohastobecomeastandardized,reliableforestproductin
thePhilippines.Inthefieldsurveysandinterviews,thiswashighlightedascriticalitemand
thereforespecifiedasoneoftheimplementationstrategies.Existingbamboostandshavetobe
identifiedthroughfieldsurveysand/ormoretechnologicaerialmapping.Formingofsupply
networksandharvestingtrainingsthemanagementofthesestandscanbestrengthenedand
sustainableharvestingamountsdetermined.Durable,reliable,rawmaterialqualityhastobe
producedthroughadefineddrying,storage,andtreatmentprocess,whichfollowsquality
control,environmental‐andhealthcriteriaaswellasefficienttechnicalprocesses.Researchon
treatmentmethodsisoneessentialcomponentforbamboo,sincethereisnoscientific
recommendationwithoutbottlenecksavailableaspertoday.Allitemsontheroadmapare
summarizedinFigure13.
Figure13.Systemicapproachonsupplychainofstrengthgradedrawmaterial.
Figure 12. Systemic approach on integrating of stakeholder requirements.
Sustainability 2016,8, 151 20 of 26
(4)
Further, the technology application at larger scale requires a sustainably generated, accessible
supply of quality graded bamboo. Bamboo has to become a standardized, reliable forest product
in the Philippines. In the field surveys and interviews, this was highlighted as critical item
and therefore specified as one of the implementation strategies. Existing bamboo stands have
to be identified through field surveys and/or more technologic aerial mapping. Forming of
supply networks and harvesting trainings the management of these stands can be strengthened
and sustainable harvesting amounts determined. Durable, reliable, raw material quality has to
be produced through a defined drying, storage, and treatment process, which follows quality
control, environmental- and health-criteria as well as efficient technical processes. Research
on treatment methods is one essential component for bamboo, since there is no scientific
recommendation without bottlenecks available as per today. All items on the road map are
summarized in Figure 13.
Sustainability2016,8,15119of25
(3) Stakeholderparticipation,capacitybuildingandacloseinteractionbetweenlowincomegroups,
professionals,governmentsandfurtherstakeholdergroupswasreflectedthroughastrategyon
stakeholderinvolvement,displayedinFigure12.Theparticipatoryprocessgivesconsideration
totheneedandconcernsoflowincomegroupsinplanning,construction,andpostoccupation.
Thestrategydescribeswhereandhowparticipationandcapacitybuildinghasbeenintegrated
inthetechnologydevelopment.Continuousprocesssimplificationsandparallelskill
developmentfacilitateinvolvementofpeople.Postoccupationalcustomeracceptancetesting
accordingtocorporatestandardsallowtoidentifyfurtherinnovationpotentialsandare
thereforeconnectedtothearea‘innovation’intheimplementationroadmap.Policyapproval
andexpansionhasbeentargetedthroughnational,regionalandglobalbestpracticesharingand
advocacyandisconnectedtotheareaoflegalapprovalunderresearch.
Figure12.Systemicapproachonintegratingofstakeholderrequirements.
(4) Further,thetechnologyapplicationatlargerscalerequiresasustainablygenerated,accessible
supplyofqualitygradedbamboo.Bamboohastobecomeastandardized,reliableforestproductin
thePhilippines.Inthefieldsurveysandinterviews,thiswashighlightedascriticalitemand
thereforespecifiedasoneoftheimplementationstrategies.Existingbamboostandshavetobe
identifiedthroughfieldsurveysand/ormoretechnologicaerialmapping.Formingofsupply
networksandharvestingtrainingsthemanagementofthesestandscanbestrengthenedand
sustainableharvestingamountsdetermined.Durable,reliable,rawmaterialqualityhastobe
producedthroughadefineddrying,storage,andtreatmentprocess,whichfollowsquality
control,environmental‐andhealthcriteriaaswellasefficienttechnicalprocesses.Researchon
treatmentmethodsisoneessentialcomponentforbamboo,sincethereisnoscientific
recommendationwithoutbottlenecksavailableaspertoday.Allitemsontheroadmapare
summarizedinFigure13.
Figure13.Systemicapproachonsupplychainofstrengthgradedrawmaterial.
Figure 13. Systemic approach on supply chain of strength graded raw material.
4. Discussion
This chapter discusses the results presented in the chapter before according to the criteria validity
and transferability of methodology and results.
Method: Validity of using qualitative data
-
This paper derives Sustainability Assessment Criteria through qualitative research methods such
as interviews and field observations. Science debates about the validity of qualitative assessments
in comparison to quantitative ones. Seemingly less transparent evaluation methods are among the
most common criticisms, which is opposed by researchers describing the strength of qualitative
data analysis [
44
,
70
], when carried out systematically and holistically. Typically, qualitative
sample sizes are limited, but rich in data [
40
]. The paper addresses the concerns through
a systematic data generation and content analysis including coding, sorting and sifting of data.
The evaluation of qualitative data is moreover based on human characteristics, understanding,
knowledge, and social context allowing for an encyclopedic evaluation of an issue or case [
44
].
The paper has overcome the risk of biased findings through scientifically recognized validation
methods such as: triangulation through multiple sources, long-term engagement in the field,
application of multiple methods to validate findings, and the evaluation through more than one
observer or author.
Method: Validity of presenting a roadmap for development
-
This paper looks at an innovation potential, for which data has to be generated first, before it can
be compared. The results can therefore be understood as Part 1 of a MCDM. Once all suggested
Sustainability 2016,8, 151 21 of 26
data sets are generated and comprehensively evaluated, a holistic performance comparison
between the alternative and the conventional building method is enabled. At this point, a Part
2 of the paper is suggested, which will provide a technology raking and recommendation for
decision-makers.
Transferability: Application in further geographies
-
This paper assesses an alternative method for house construction in the socio-economic and
geographic boundaries of the Philippines. In [
32
] it is highlighted, that there is a call for
Sustainability Assessments to transfer from local to global level. A fine balance is to strike
for creating sufficiently meaningful data for the local context, and the wish to create valid
generalizations and transfers [
71
]. Sustainability assessments in Development Cooperation are
often found to be specific, e.g. due to their specific cultural context [
72
]. While this paper assessed
the Philippine context of social housing, the strategic approach for creating sustainable building
solutions has general validity for the tropical context and low-rise construction. It can therefore
be adapted to other bamboo growing countries under integration of local specifications. The
Philippines, with its natural disasters, its low affordability and high poverty, represents further a
challenging environment for a building technology and can therefore be seen as pathfinder for an
expansion in Asia-Pacific or around the globe. However, for it to be successfully applied at scale,
a complex set of wider interlinked aspects has to be tackled.
Transferability: Application to further building materials or sectors
-
For increasing the impact of Sustainability Assessments, a transfer from product to sector
level is suggested in [
32
]. This paper captures stakeholder requirements on the sector level
of social housing. The organic material bamboo brings about requirements, which are nearest
to the sectors of other forest products. Nevertheless, its specific supply chain and technical
construction concepts remains connected to bamboo and requires adjustment when other
materials are considered.
5. Conclusions
The general objective of the paper to develop a roadmap for transforming the potential bamboo
raw material into a sustainable building technology suitable for social housing in the Philippines has
been achieved. Fifteen context-specific Sustainability Assessment Criteria have been identified through
processing of qualitative stakeholder data. Data was categorized into one or several of the sustainability
dimensions society, ecology, economy, technology, or governance and processed through multiple
qualitative sampling strategies. The paper then presented a roadmap describing a multi-perspective
development process showing the implementation path for the theoretic potential. The roadmap
contains 28 action items derived by correlation of the Sustainability Criteria with four Implementation
Strategies: (1) Research about and (2) implementation of the technology, (3) Stakeholder participation;
and (4) Supply chain development. For generating measurable results in these 28 action items,
quantitative and qualitative recognized one-dimensional methods are named. Once the action items
are put into practice, the generated one-dimensional data will enable multi-dimensional, holistic
performance assessment of the alternative building technology as suggested by Multi-Criteria Decision
Making theory. As such, the paper contributes to enable future guidance for decision-makers whether
or not to change current systems from a consumer-, policy-maker, or construction-professional
viewpoints. With that, the approach described in this paper brings attention to an unexplored,
highly relevant research field for the future: sustainable and resilient building for low-income dwellers
in rapidly growing urban centers in Asia, Latin America, and Africa.
Acknowledgments:
Acknowledgement is given to Base, an initiative of Hilti Foundation on sustainable affordable
housing, which has funded this research. Furthermore we acknowledge Chalmers Area of Advance Built Environment
profile Responsible Use of Resources” to support the affordable building-related research. Thirdly, the contribution
of Bambou Science et Innovation is highly valued.
Sustainability 2016,8, 151 22 of 26
Author Contributions:
The study was designed and the article was written by Corinna Salzer. Holger Wallbaum
contributed to the methodology framework of the research. Jean Luc Kouyoumji contributed content to the
comparison with Timber construction in Europe, Luis Felipe Lopez to Bamboo Construction in Latin America,
and all three to triangulate the method selection for individual information units of the roadmap.
Conflicts of Interest: The authors declare no conflict of interest.
Appendix
Interview Guide for different stakeholder clusters:
Table A1. Guide for Interviews with stakeholder clusters (1) and (3A).
No. Stakeholder Clusters: (1) Inhabitants of Traditional Bamboo Houses in the Philippines and (3A)
Low Income Groups in Need of Social Housing
1Since when have you lived in your current house, with how many family members do you live there
and what is the size of the house?
2 What is the material your current house is made from? Why did you choose it?
3
How do you like living in your current house? Have you ever lived in a different house? How was it in
comparison to now?
4 Have you been involved in the construction of your house?
5 Do you know where the materials of your house were sourced?
6Do you feel save in your house during earthquakes or typhoons? Have you experienced damage to
your house during extreme impacts?
7 What is your current source of income? How high is your monthly income?
8 How much did you spend for the construction of your house? Do you still pay the installments?
9 How often do you have to maintain your house?
10 Which building method would you prefer if you could freely choose?
Table A2. Guide for Interviews and Expert Review with stakeholder clusters (2A) and (2B).
No. Stakeholder Clusters: Building Sector using Forest Products in (2A) Latin America and (2B) Europe
1
At which scale is the forest product being used for house construction today/What is its current market
share? What is the track record of the technology?
2 Among which customer group is the building technology applied the most?
3
What is the dominating perception towards this building technology- by its users and non-users? How
is the customer acceptance of the technology in general?
4
Were or are there major barriers hindering the application of a building technology using bamboo in the
pillars economy, ecology, society, technology, or governance?
5Were or are there major drivers/opportunities supporting the application of a building technology
using bamboo in the pillars economy, ecology, society, technology, or governance?
6 What roles do human skills and capacity building play?
7What is the common construction process and how relevant are specific optimization
processes/concepts?
8 What role does research and development and innovation play in general?
9 What role does the supply chain play?
10 What roles do government policies or incentives and environmental concerns play?
Sustainability 2016,8, 151 23 of 26
Table A3. Guide for Interviews with stakeholder cluster (3B–3D).
No. Stakeholder Clusters: Stakeholders in Social Housing in the Philippines (3B–3D)
1
How big is the housing need in the social housing segment? How many houses are currently supplied
by your organization specifically and private sector, government, NGOs or self-build homes in general?
Is there a gap between supply and need?
2 What are requirements in social housing, how would you describe the needed value proposition?
3 What are the most common building materials and concepts applied in low-cost housing segments?
4What role does perception towards a building material for its success at the market play and how do
you evaluate the perception of bamboo today?
5
Were or are there major barriers hindering the application of a building technology using bamboo in the
pillars economy, ecology, society, technology, or governance?
6Were or are there major drivers / opportunities supporting the application of a building technology
using bamboo in the pillars economy, ecology, society, technology, or governance?
7 What roles do human skills and capacity building play?
8What is the common construction process and how relevant are specific optimization
processes/concepts?
9 What role does research and development and innovation in general play?
10 What roles do supply chains play?
11 What roles do government policies or incentives and environmental concerns play?
Table A4. Guide for Semi-Structured Interviews with stakeholder cluster (3E).
No. Stakeholder Clusters: Raw Material Suppliers for Housing Made from Bamboo (3E)
1 Which bamboo species do you sell?
2 In which quantity this species would be harvestable?
3 What is the regular price for bamboo for purchase at harvesting location?
4 Do you regularly supply customers with bamboo or just provide it on an occasion/demand basis?
5
Can the bamboo be delivered to collection points and what are prices including this transportation?
6 What is the timeline from harvesting to delivery and which mode of transport would be chosen?
7 Are there any middle men, consolidators, or sub-contractors involved?
8 What is the income share between land owner, harvester, and transport?
9 Is bamboo supply the only source of income or one among others?
10 Would you be interested in extending your bamboo business in the future?
References
1.
United Nations Environment Programme (UNEP)-SBCI. Buildings and Climate Change: Summary for
Decision-Makers; UNEP: Paris, France, 2009.
2.
United Nations Human Settlements Programme (UN Habitat). Sustainable Housing for Sustainable Cities:
A Policy Framework for Developing Countries; UN Habitat: Nairobi, Kenya, 2012.
3.
Swiss Society of Engineers and Architects (SIA). SIA 112 /1—Nachhaltiges Bauen—Hochbau; SIA: Zurich,
Switzerland, 2004.
4.
United Nations Human Settlements Programme (UN Habitat). Going Green: A Handbook of Sustainbale
Housing Practices in Developing Countries; UN Habitat: Nairobi, Kenya; United Nations Economic and Social
Commission for Asia and the Pacific: Bangkok, Thailand, 2012.
5.
United Nations Environment Programme (UNEP). Sustainable Solutions for Social Housing: Guidelines for
Project Developers; UNEP: Nairobi, Kenya, 2013.
6.
United Nations Human Settlements Programme (UN-Habitat). State of the World
'
s Cities; UN-Habitat:
Nairobi, Kenya, 2013.
Sustainability 2016,8, 151 24 of 26
7.
United Nations Economic and Social Commission for Asia and the Pacific (UN-ESCAP); United Nations
Human Settlements Programme (UN-Habitat). The State of Asian Cities 2010/2011; UN-ESCAP: Bangkok,
Thailand; UN-Habitat: Nairobi, Kenya, 2011.
8.
Cinco, T. Sever Wind Impacts and Vulnerability of Housing to Such; Philippine Atmospheric, Geophysical, and
Astronomical Services Administration (PAGASA): Quezon City, Philippines, 2013.
9.
Association of Structural Engineers Philippines. Post-Disaster Damage Assessment—Earthquake Bohol
Philippines, 2013; ASEP: Quezon, Philippines, 2013.
10.
United Nations Human Settlements Programme (UN Habitat)-Philippines. Country Programme Document
2008–2009 Philippines; UN Habitat: Nairobi, Kenya, 2009.
11.
Intergovernmental Panel on Climate Change (IPCC). Fifth Assessment Report Climate Change 2014: Impacts,
Adaptation, and Vulnerability; IPCC: Geneva, Switzerland, 2014.
12.
Wallbaum, H.; Ostermeyer, Y.; Salzer, C.; Escamilla, E.Z. Indicator based sustainability assessment tool for
affordable housing construction technologies. Ecol. Indic. 2012,18, 353–364. [CrossRef]
13. Rizvi, Z.M. Pro-poor housing: An idea whose time has come. Hous. Financ. Int. 2010,24, 15–20.
14.
Forest Products Research and Development Institute (FPRDI). Utilization, Collection and Trade of Tropical
Non-Wood Forest Products in the Philippines; FPRDI: Los Banos, Philippines, 2002.
15.
Waas, T.; Hugé, J.; Block, T.; Wright, T.; Benitez-Capistros, F.; Verbruggen, A. Sustainability Assessment
and Indicators: Tools in a Decision-Making Strategy for Sustainable Development. Sustainability
2014
,
6, 5512–5534. [CrossRef]
16.
Feige, A.; Wallbaum, H.; Krank, S. Harnessing stakeholder motivation: Towards a Swiss sustainable building
sector. Build. Res. Inf. 2011,39, 504–517. [CrossRef]
17.
Mendoza, G.A.; Martins, H. Multi-criteria decision analysis in natural resource management: A critical
review of methods and new modelling paradigms. For. Ecol. Manag. 2006,230, 1–22. [CrossRef]
18.
Turcksin, L.; Macharis, C.; Lebeau, K.; Boureima, F.; van Mierlo, J.; Bram, S.; de Ruyck, J.; Mertens, L.;
Jossart, J.M.; Gorissen, L.; et al. A multi-actor multi-criteria framework to assess the stakeholder support for
different biofuel options: The case of Belgium. Energy Policy 2011,39, 200–214. [CrossRef]
19.
Van Passel, S.; Meul, M. Multilevel and multi-user sustainability assessment of farming systems.
Environ. Impact Assess. Rev. 2012,32, 170–180. [CrossRef]
20.
Vermote, L.; Macharis, C.; Putman, K. A road network for freight transport in flanders: Multi-actor
multi-criteria assessment of alternative ring ways. Sustainability 2013,5, 4222–4246. [CrossRef]
21.
Mardani, A.; Jusoh, A.; Zavadskas, E.; Cavallaro, F.; Khalifah, Z. Sustainable and renewable energy:
An overview of the application of multiple criteria decision making techniques and approaches. Sustainability
2015,7, 13947–13984. [CrossRef]
22.
Wang, J.J.; Jing, Y.Y.; Zhang, C.F.; Zhao, J.H. Review on multi-criteria decision analysis aid in sustainable
energy decision-making. Renew. Sustain. Energy Rev. 2009,13, 2263–2278. [CrossRef]
23.
Zurbrügg, C.; Caniato, M.; Vaccari, M. How Assessment Methods Can Support Solid Waste Management in
Developing Countries—A Critical Review. Sustainability 2014,6, 545–570. [CrossRef]
24.
Cobacho, B.; Caballero, R.; González, M.; Molina, J. Planning federal public investment in Mexico using
multiobjective decision making. J. Oper. Res. Soc. 2009,61, 1328–1339. [CrossRef]
25.
Mardani, A.; Jusoh, A.; Zavadskas, E.K. Fuzzy multiple criteria decision-making techniques and
applications—Two decades review from 1994 to 2014. Expert Syst. Appl. 2015,42, 4126–4148. [CrossRef]
26.
Akadiri, P.O.; Olomolaiye, P.O.; Chinyio, E.A. Multi-criteria evaluation model for the selection of sustainable
materials for building projects. Autom. Constr. 2013,30, 113–125. [CrossRef]
27.
Contreras-miranda, W.; Cloquell-ballester, V.; de Contreras, O. Las técnicas de decisión multicriterio en
la selección de componentes estructurales, a partir de la tecnología de la madera, para construcción de
viviendas sociales en Venezuela. Madera Y Bosques 2010,16, 7–22.
28.
Mulliner, E.; Smallbone, K.; Maliene, V. An assessment of sustainable housing affordability using a multiple
criteria decision making method. Omega 2013,41, 270–279. [CrossRef]
29.
Medineckiene, M.; Zavadskas, E.K.; Björk, F.; Turskis, Z. Multi-criteria decision-making system for
sustainable building assessment/certification. Arch. Civ. Mech. Eng. 2015,15, 11–18. [CrossRef]
30.
Tupenaite, L.; Zavadskas, E.K.; Kaklauskas, A.; Turskis, Z.; Seniut, M. Multiple criteria assessment of
alternatives for built and human environment renovation. J. Civ. Eng. Manag.
2010
,16, 257–266. [CrossRef]
Sustainability 2016,8, 151 25 of 26
31.
MacHaris, C.; Turcksin, L.; Lebeau, K. Multi actor multi criteria analysis (MAMCA) as a tool to support
sustainable decisions: State of use. Decis. Support Syst. 2012,54, 610–620. [CrossRef]
32.
Zijp, M.; Heijungs, R.; van der Voet, E.; van de Meent, D.; Huijbregts, M.; Hollander, A.; Posthuma, L.
An Identification Key for Selecting Methods for Sustainability Assessments. Sustainability
2015
,7, 2490–2512.
[CrossRef]
33.
Reed, M.S. Stakeholder participation for environmental management: A literature review. Biol. Conserv.
2008,141, 2417–2431. [CrossRef]
34.
Bal, M.; Bryde, D.; Fearon, D.; Ochieng, E. Stakeholder engagement: Achieving sustainability in the
construction sector. Sustainability 2013,5, 695–710. [CrossRef]
35.
Lundholm, C.; Stöhr, C. Stakeholder Dialogues and Shared Understanding: The Case of Co-Managing
Fisheries in Sweden. Sustainability 2014,6, 4525–4536. [CrossRef]
36.
Institute of Development Studies (IDS). Community-Driven Disaster Risk Management and Reduction in the
Philippines; IDS: Satterthwaite, UK, 2011.
37.
Thabrew, L.; Wiek, A.; Ries, R. Environmental decision making in multi-stakeholder contexts: Applicability
of life cycle thinking in development planning and implementation. J. Clean. Prod.
2009
,17, 67–76. [CrossRef]
38.
Grafakos, S.; Flamos, A.; Enseñado, E. Preferences matter: A constructive approach to incorporating
local stakeholders’ preferences in the sustainability evaluation of energy technologies. Sustainability
2015
,
7, 10922–10960. [CrossRef]
39.
Fraser, E.D.G.; Dougill, A.J.; Mabee, W.E.; Reed, M.; McAlpine, P. Bottom up and top down: Analysis of
participatory processes for sustainability indicator identification as a pathway to community empowerment
and sustainable environmental management. J. Environ. Manag. 2006,78, 114–127. [CrossRef] [PubMed]
40.
Patton, M.Q. Qualitative Research & Evaluation Methods Integrating Theory and Practice, 4th ed.; SAGE: London,
UK, 2015.
41.
Singh, R.K.; Murty, H.R.; Gupta, S.K.; Dikshit, A.K. An overview of sustainability assessment methodologies.
Ecol. Indic. 2012,15, 281–299. [CrossRef]
42.
World Commission on Environment and Development (WCED). Our Common Future: World Commission on
Environment and Development; Oxford University Press: Oxford, UK, 1987.
43.
United Nations Environment Programme (UNEP). Sustainable Building Policies in Developing Countries (SPOD):
Promoting sustainable building and construction practices; UNEP: Paris, France, 2011.
44.
Chowdhury, M.F. Coding, sorting and sifting of qualitative data analysis: Debates and discussion.
Qual. Quant. 2015,49, 1135–1143. [CrossRef]
45.
Wehmer, N.; United Nations Economic and Social Commission for Asia and the Pacific (UN-ESCAP).
A Conceptual Framework for Social Housing in the Philippines; UN-ESCAP: Bangkok, Thailand, 2012.
46.
Base- An Initative of Hilti Foundation. Base- Sustainable and Resilient Social Housing in the Philippines.
2015. Available online: http://www.base-builds.com/ (accessed on 30 November 2015).
47.
Pope, J.; Annandale, D.; Morrison-Saunders, A. Conceptualising sustainability assessment. Environ. Impact
Assess. Rev. 2004,24, 595–616. [CrossRef]
48.
Krank, S.; Wallbaum, H. Lessons from seven sustainability indicator programs in developing countries of
Asia. Ecol. Indic. 2011,11, 1385–1395. [CrossRef]
49.
Homeless People’s Federation of the Philippines. Homeless People’s Federation of the Philippines. Available
online: http://www.achr.net/index.php (accessed on 30 November 2015).
50.
Paudel, S.K.; Lobovikov, M. Bamboo housing: Market potential for low-income groups. J. Bamboo Rattan
2003,2, 381–396. [CrossRef]
51.
Ostermeyer, Y.; Wallbaum, H.; Reuter, F. Multidimensional Pareto optimization as an approach for
site-specific building refurbishment solutions applicable for life cycle sustainability assessment. Int. J.
Life Cycle Assess. 2013,18, 1762–1779. [CrossRef]
52.
International Organization for Standardization (ISO). ISO 22157—1 Bamboo—Determination of Physical and
Mechanical Properties—Part 1: Requirements; ISO: Geneva, Switzerland, 2004.
53.
International Organization for Standardization (ISO). ISO 22157—2 Bamboo—Determination of Physical and
Mechanical Properties—Part 2: Laboratory Manual; ISO: Geneva, Switzerland, 1989; Volume 53, p. 160.
54.
Association of Seismic Engineers Colombia. NSR-10: Section E: One and two-Story Structures from Bahareque;
AIS: Bogota, Colombia, 2009.
55. Villegas, M. New Bamboo Architecture and Design; Villegas Editores: Bogota, Colombia, 2003.
Sustainability 2016,8, 151 26 of 26
56.
European Organization for Technical Assessment. European Technical Approval Guidelines
(ETAGs). Available online: http://www.eota.eu/en-GB/content/etags-used-as-ead/26/ (accessed on
30 November 2015).
57.
Östman, B.; Källsner, B. National Building Regulations in Relation to Multi-Storey Wooden Buildings in Europe;
SP Trätek Växjö University: Kalmar, Sweden, 2011; pp. 1–26.
58.
European Standard. EN 594 Timber Structures—Test Methods—Racking Strength and Stiffness of Timber Frame
Wall Panels; European Standardisation Organisations: Brussels, Belgium, 2011.
59.
Housing Technology Development Office (HTDO). Manual on Accreditation of Innovative Technologies for
Housing; Housing Technology Development Office Philippines, National Housing Authority: Quezon City,
Philippines, 2015.
60.
Housing and Land Use Regulatory Board (HLURB). Revised Implementing Rules and Regulations for Economic
and Socialized Housing Projects—B.P. 220; HLURB: Quezon, Philippines, 2008.
61.
International Organization for Standardization (ISO). EN ISO 7726—Indoor Climate: Instruments for Physical
Measurement; ISO: Geneva, Switzerland, 2001.
62.
International Organization for Standardization (ISO). ISO 14044-Environmental Management, Life Cycle
Assessment, Requirements and Guidelines; ISO: Geneva, Switzerland, 2006.
63.
International Organization for Standardization (ISO). ISO 21581 Timber Structures—Static and Cyclic Lateral
Load Test Methods for Shear Walls; ISO: Geneva, Switzerland, 2010.
64.
Japanese Industrial Standard (JIS). JIS A 1304—Method of fire resistance test for structural parts of buildings.
J. Chem. Inf. Model. 2011,53, 160.
65.
International Organization for Standardization (ISO). Elements of Building Construction—Part 1: General
Requirements; Fire-Resistance Tests; ISO: Geneva, Switzerland, 1999; Volume ISO 834–1, p. 25.
66.
Association of Structural Engineers Philippines. National Structural Code of the Philippines, Volume 1—Buildings,
Towers and Other Vertical Structures, 6th ed.; ASEP: Quezon, Philippines, 2010.
67.
De Dear, R.J.; Brager, G.S. Thermal comfort in naturally ventilated buildings: Revisions to ASHRAE Standard
55. Energy Build. 2002,34, 549–561. [CrossRef]
68.
International Organization for Standardization (ISO). ISO 22156—Bamboo—Structural Design; ISO: Geneva,
Switzerland, 2004.
69.
Association of Structural Engineers Philippines. National Structural Code of the Philippines, Volume
3—Residential Housing, 1st ed.; ASEP: Quezon, Philippines, 2016.
70.
Pierre, E.A.S.; Jackson, A.Y. Qualitative Data Analysis After Coding. Qual. Inq.
2014
,20, 715–719. [CrossRef]
71.
Yin, R.K. Validity and generalization in future case study evaluations. Evaluation
2013
,19, 321–332. [CrossRef]
72.
Hugé, J.; Mukherjee, N.; Fertel, C.; Waaub, J.P.; Block, T.; Waas, T.; Koedam, N.; Dahdouh-Guebas, F.
Conceptualizing the Effectiveness of Sustainability Assessment in Development Cooperation. Sustainability
2015,7, 5735–5751. [CrossRef]
©
2016 by the authors; licensee MDPI, Basel, Switzerland. This article is an open access
article distributed under the terms and conditions of the Creative Commons by Attribution
(CC-BY) license (http://creativecommons.org/licenses/by/4.0/).
... Despite the benefits of ABTs and their potential to solve South Africa's housing gap, their use in housing construction is limited. According to Botes (2013) and Salzer et al. (2016), traditional brick, concrete and steel houses are most desired and deemed contemporary by the typical citizen. South Africans believed that ABT-built houses were solely for the poor. ...
Article
Full-text available
Purpose- This study aims to evaluate the perception of the local experts and end users on the drivers, barriers and strategies to the use of alternative building technologies (ABTs), with a focus on sandbag building technologies (SBTs) in the provision of sustainable housing in South Africa towards improving the public's understanding of SBTs. Design/methodology/approach-This research adopted a qualitative approach that used focus group meetings as the primary data collection method for this study. This study's focus group participants comprised ABT experts and end users of ABT houses in South Africa who were selected using a convenient sampling technique. The data were recorded, transcribed verbatim and analysed using NVivo 11 software. Findings-This study found that the perceived drivers to using ABTs such as SBT comprise sustainability, affordability, job creation potentials, fire-resistant and earthquake resistance. This study revealed strategies for the SBTs, including awareness, building sandbag prototypes across cities and training. Practical implications – This study’s findings have practical implications for the practice and praxis of ABT implementation and uptake in South Africa. This study provides a framework for broadening the worldwide understanding of use and uptake of SBTs to provide sustainable and affordable housing. Originality/value – This study adds significantly to the limited body of knowledge on ABTs, focusing on sandbag houses. Consequently, the findings provide policymakers with information on the expert and enduser perspectives on the barriers and strategies to using ABTs.
... However, most of the existing assessment approaches merely consider environmental performance, thus, leading to a non-comprehensive evaluation (Akadiri et al., 2013;Ding, 2008). Tools and methods that include other sustainability requirements, such as economic, social, technical, and functional have been recently developed (Ali and Al Nsairat, 2009;Salzer et al., 2016). ...
Article
In this work, we present the development and characterisation of new cement-based composite panels reinforced with fibres recovered from wastes of protective technical clothing. The developed panels present a flexural strength (∼15 MPa) and fracture toughness (∼3.5 KJ/m²) that are suitable for their application on ventilated façades. The environmental impact of these panels was evaluated through the life-cycle assessment (LCA) from a cradle-to-gate approach and was compared with similar engineered materials and commercial materials used for ventilated façades (fibre cement facing tiles, ceramic tiles, and natural stone plates). Two functional units were assessed: the panel necessary to cover 1 m² of façade, and the panel necessary to cover 1 m² of façade providing a maximum bending stress of 17 or 24 MPa. For 17 MPa, the new composite developed has presented similar environmental performance to fibre cement facing tiles and significantly better than the traditional ceramic tiles and natural stone plates.
... Moreover, the built environment is responsible for more than 40% of the global consumption of energy and one-third of the global greenhouse gas emissions and, therefore, exhibits the highest potential to achieve a significant reduction in the environmental footprint [3]. Population growth in urban areas together with natural disasters [4] further increases the demand for housing solutions [5]. Furthermore, the production of conventional construction materials, such as ceramic, steel, and cement, is related to high levels of the primary energy demand and CO 2 emissions [6]. ...
Article
Full-text available
The provision of sustainable housing solutions is one of the main challenges in emerging economy countries. Furthermore, it is clear that a sustainable solution should be based on renewable bio-based materials. Scientific and practical evidence clearly suggests that the use of bamboo in the provision of housing solutions provides communities with both environmental and socioeconomic benefits via this strategy. One barrier to the promotion of this type of solution is the lack of knowledge on structural design and environmental performance. Moreover, access to assessment tools and methodologies is limited. The use of simplified Life Cycle Assessment (LCA) has exhibited great potential to increase accessibility, but the generation of life cycle inventory data remains a major issue. In this paper, we describe the development of a methodological approach to use parametric design to generate the data required to carry out simplified LCA of social housing solutions. Moreover, we present a case study assessing a housing unit using cement bamboo frame technology developed by the Base Bahay Foundation in the Philippines. The main parameters for the LCA of the buildings were identified through sensitivity analysis. Moreover, they show that parametric design is a valid approach to overcome the challenges of data generation at early stages of design. The proposed approach would enable users without civil and/or engineering background to carry out simplified LCA calculations. Thus, through methodological approaches, it is possible to reduce significantly the complexity associated with LCA and open new avenues for it application.
... However, most of the existing assessment approaches merely consider environmental performance, thus, leading to a non-comprehensive evaluation (Akadiri et al., 2013;Ding, 2008). Tools and methods that include other sustainability requirements, such as economic, social, technical, and functional have been recently developed (Ali and Al Nsairat, 2009;Salzer et al., 2016). ...
Article
Full-text available
Within the building construction sector, fiber cement boards have attracted interest as facade cladding materials in the last ten years, especially those that incorporate-for reinforcing purposes-natural and/or recycled synthetic fibers (i.e, from the textile industry). So far, the design-governing parameters of facade cladding panels have been mechanical strength, durability, constructability, aesthetics, insulation capacity, and fire resistance. From the sustainability perspective, the impact of the facade on the economic and energy efficiency performance is most often the parameter that leads the decision-making process. Within this context, the quantification of the sustainability performance of the facade-accounting for economic, environmental, and social indicators-is unfrequently carried out in design and project phases, this being attributed to the lack of methodologies that allow considering and quantifying some relevant indicators representative of the facade sustainability performance. As consequence, decisions made based on solely economic and on some of the environmental indicators might lead to solutions with lower sustainability performance than that required (or expected). Recycled textile waste fabric-reinforced cement board as a facade-cladding material for building envelopes is the focus of this research. In order to characterize the fire resistance, and thermal and acoustic insulation-as relevant service-ability parameters-of this material, an experimental program was carried out. Likewise, the sustainability performance of this facade-cladding is assessed through a method based on the Integrated Value Model for Sustainability Assessment (MIVES). This multi-criteria decision making (MCDM) model relies on the value function concept and the multidisciplinary participation of experts to identify and quantify the relevant indicators of the facade sustainability performance and the relative importance of indicators and requirements. The MIVES-based model generated for this research can be straightforwardly used for assessing the sustainability performance of facade-cladding techniques made of any material and for any type of building (and location). The application of the MIVES model led to the sustainability index of this new material for facade-cladding ranging from 0.68 to 0.71 (/1.00) for different weighting scenarios.
... Over the years, there has been a widespread drive in the building industry to adopt more sustainable techniques [1]. This widespread adoption of sustainable practices is a result of climate change and the environmental implications of development [2]. While the UN's sustainable development goals (SDGs) continue to emphasize the growth element in its interpretation of sustainable development, achieving such goals in the construction industry remains difficult [3]. ...
Article
Full-text available
Cement manufacture contributes about 5-7% of the global carbon dioxide emission. The fastest short-term remedy is to replace parts of ordinary Portland cement (OPC) in concrete with supplementary cementitious materials (SCMs) to reduce CO2 emissions. Calcined clay and limestone filler have proven to be potential substitutes to good quality SCMs such as fly ash and slag because of their abundance, low cost, and potential reactivity to calcium hydroxide to form calcium silicate hydrates (C-S-H) which are responsible for the strength and other mechanical properties of concrete. A life cycle assessment (LCA) to evaluate the environmental impact of mortar with cal-cined clay and limestone filler in reinforced concrete (RC) column retrofitting is carried out using data from a multipurpose complex project in Rizal province in the Philippines. A total of four ret-rofitting methods are evaluated based on two retrofitting techniques (RC column jacketing and steel jacketing) with two material alternatives (pure OPC-based mortar and mortar with partial replacements). Results show that RC column jacketing using patched mortar with partial replacement of calcined clay and limestone fillers is the least environmentally damaging retrofit option. The use of these SCMs resulted in a 4-7% decrease in global warming potential and a 2-4% decrease in fine particulate matter formation. Meanwhile, RC column jacketing decreased the effect on human carcinogenic toxicity by 75% compared to steel jacketing.