Early Stage Design Decisions: The Way to Achieve Sustainable
Buildings at Lower Costs
Luís Bragança, Susana M. Vieira, and Joana B. Andrade
Building Physics & Construction Technology Laboratory, School of Engineering, University of Minho, 4800-058 Guimaraes, Portugal
Correspondence should be addressed to Lu´
ıs Braganc¸a; email@example.com
Received August ; Accepted October ; Published January
Academic Editors: H. Cui and J. Lu
Copyright © Lu´
ıs Braganc¸a et al. is is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
e construction industry attempts to produce buildings with as lower environmental impact as possible. However, construction
activities still greatly aect environment; therefore, it is necessary to consider a sustainable project approach based on its
performance. Sustainability is an important issue to consider in design, not only due to environmental concerns but also due to
economic and social matters, promoting architectural quality and economic advantages. is paper aims to identify the phases
through which a design project should be developed, emphasising the importance and ability of earlier stages to inuence
sustainability, performance, and life cycle cost. en, a selection of sustainability key indicators, able to be used at the design
conceptual phase and able to start predicting environmental sustainability performance of buildings is presented. e output of
this paper aimed to enable designers to compare and evaluate the consequences of dierent design solutions, based on preliminary
data, and facilitate the collaboration between stakeholders and clients and eventually yield a sustainable and high performance
building throughout its life cycle.
“Instead of trying to “force t” sustainable princi-
ples into an existing and oen unreceptive manu-
facturing system, it may be useful to approach the
subject from the opposite direction, and consider
how functional objects might be designed and
manufactured to be compatible with principles of
sustainable development” .
Sustainability is an important issue to consider in design,
not only due to the environmental concerns but also due to
economic and social issues, as they promote architectural
quality and have economic advantages . Sustainable design
besides contributing to more comfortable and pleasant spaces
for living allows economic savings through ecient design
while the buildings’ environmental footprint is reduced.
e importance of considering sustainability in design
stage meets the need for nding long-term solutions that
warrant well-being and minimize the needs for natural
resources as land use, biodiversity, water, air, and energy. If a
project is well planned and sustainable criteria are included
in its early approach, the possibility to reduce negative
impacts is greater and the cost of criteria implementation is
greatly reduced, as illustrated in Figure .Improvementofthe
building’s sustainability performance must begin already in
the design stage, as the potential of optimisation in project
building and the construction costs are lower.
A building’s project obeys general criteria that allow its
development on later stages; usually, main criteria respond to
functional, economic, social, and time requirements. How-
ever, those are not enough to create a consistent base to
achieve optimal results for the building. New criteria and
approach, that are usually not considered, can bring advan-
tages to the project, favouring improvement of its perfor-
mance and reducing its nal cost . e sooner the project
goals are dened and the new criteria are integrated, the more
sustainable the building will be.
For the building analysis and sustainability performance
prediction in early stage phases of design, several indictors
need to be identied and selected. e analysis of the work
that has been carried out and published by the research
Hindawi Publishing Corporation
e Scientiﬁc World Journal
Volume 2014, Article ID 365364, 8 pages
e Scientic World Journal
Possibility to inuence impacts
Impacts and costs of
Impacts and costs of
Cumulated impacts and
Impacts and costs during use phase
Planning Construction Use phase and maintenance
Environmental impacts and costs
F : Inuence of design decisions on life cycle impacts and costs .
team of the Building Physics and Construction Technology of
University of Minho since [–]corroboratesthisneed.
Braganc¸a and Mateus publications [,]presentprevious
work from the authors’ research team and are in line with
the new CEN standards for sustainable construction [–],
the European energy directive ,andalsomajorEuropean
research projects as perfection , SuPerBuildings , and
Open House . Furthermore, a new set of indicators for
early stage design can also be useful for later assessment
with the new generation of building sustainability assessment
Two types of indicators can be proposed: core indicators
and additional indicators. Core indicators can be used in the
conceptual stage, whereas additional indicators can only be
used in the next phase, the predesign stage, as illustrated
in Figure . Core indicators showed to be the best solution
for the conceptual stage. e functional unit (square, cubic
meter, etc.) to quantify them should be independent from the
whole building dimensions, as these later are not available
at early design. Moreover, core indicators may be used as
a simple and faster assessment, while using both types of
indicators—core and additional indicators—gives a more
complete and exact evaluation, ensuring sustainability at all
fronts of action.
e aim of this paper is to identify the phases through
which the design project should go along, emphasising the
importance and ability of earlier stages to inuence the level
of sustainability, performance, and life cycle cost over the
project. Aerwards, there is the need to select a set of sus-
tainability indicators and to check its adaptability to the early
design. e framework of this paper is divided into two steps:
(i) identication and description of project design phases,
recognizing the main tasks of each one, and (ii) an analysis of
the adequacy and usability of the building sustainability indi-
cators, taking into account the scarce information available at
the early design stages. Only core indicators will be described
F : Core indicators and additional indicators.
as the scope of this paper focuses on the very beginning of
buildings’ design—conceptual phase. Additional indicators
will be explained in another publication.
e output of this paper aimed to enable designers to
compare and predict environmental sustainability perfor-
mance of dierent design solutions, based on preliminary
data, and facilitate the collaboration between stakeholders.
e object of the assessment is the building; it does not
include the characteristics of the building site nor its neigh-
bourhood. e scope of the analysis encompasses all stages
from material production stage to end-of-life stage.
e Scientic World Journal
F : Examples of schematic drawings resulting from the conceptual design phase; (a) spaces rst idea/local implementation; (b) rst
attempt to integrate desired sustainability measures/exterior appearance.
2. Design Phases
A sustainable design needs an integrated design process
and a more involved approach than a conventional design
process. Ensuring the high quality of design is to ensure an
interdisciplinary project team working through an integrated
planning and preparing a project to its best performance.
us, the design process is crucial because most decisions that
will determine building performance in use will be made at
A building project is developed by a sequence of phases.
e concept of design phases is related to a set of consecutive
actions that guides the development process. ese actions
are grouped in stages by their level of priority, shaping each
phase of the project. It is important to consider the value
of each action/goal/objective, predicting its importance on
buildings performance and its inuence on the projects nal
cost in order to implement each one at the adequate moment.
to manage life cycle requirements of a building during its
Although dierent names are given by dierent authors,
the phases of a building project and its goals are generally the
with the moment where the client meets the project team
and exposes the goals for the building. During this initial
phase, clients and design team share information seeking to
develop the building’s concept. e architectural program-
ming is required to dene key requirements and constraints
towards project quality. Type of architecture and formal
and functional aspects must be discussed as well as indoor
and outdoor quality desired by the client. Information of
construction, elsewhere should be suggested; subjects as
room and building functional, environmental, and spatial
performance, comfort practices, energy requirements, and so
forth should be addressed, as well as concerns on building
use, heating, cooling, lighting, ventilation, water, waste, site
works, and materials. Additionally, it is at this stage that
procurement method, project and sustainability procedures,
building design life time, organisational structure, mainte-
nance, project cost, and timescale are dealt with.
e following project step is the implementation of
the earlier dened objectives [–]. Several publications
emphasise the importance of this phase to the performance
of the building in its operational phase [–]. However,
decision making tools are rare [,]. At this phase, all
clients’ interests and design team members such as architects,
engineers, and all needed specialists are involved. is initial
phase puts into practice the clients’ instructions and exposes
the project team proposal; decisions at this early stage are of
the utmost importance while project is provisional and open
To the scope of this paper, the aforementioned tasks will
be grouped into one single design stage—the conceptual
stage. Hence, it is hereby understood as the preliminary
design phase of the building, in which the overall system con-
guration is dened, and schematic drawings and layouts will
provide an early project conguration, as seen in Figure .
At this stage, the availability of data is very poor and any
assessment has to be based mainly on assumptions. At this
stage of design, there are no drawings or any other details
about the building. e only information about the building
shape is the area of construction and the height of the
building. From these elements, all other data need to be
aspects need to be fullled in this stage: the selection of the
e Scientic World Journal
Tend e r
More accurate results
F : Design stages of a building .
for the structure (estimation); a bill of materials for the
envelope (e.g., areas of external and internal walls, area of
oors, area of roof, etc.) (estimation).
e next stage of the project begins aer the approval of
sketch studies; the design team commences the implemen-
tation of the working drawings for the construction of the
project. Once again dierent designations are given to this
phase—development phase, preproject, basic project , and
design development [,]. It is also split into two moments,
the preliminary project or predesign and the basic project.
At this moment, the general shape of the building is
developed through plans, sections, and elevations; the pro-
visional information addressed in earlier phases is conrmed
or modied. e actual/chosen solution must be compatible
with initial requirements and within the various applicable
regulations; the functional relationships between dierent
elements, spaces, and volumes must be examined, as well as
the base programming, according to any amendments agreed
between the client and the design team.
Type of construction is generally dened and the materi-
als are proposed during the meetings with the clients. Aspects
like exterior and interior wall nishing, ooring, plumbing
xtures, hardware design, type of masonry, roong materials,
and so forth shall be decided in this stage. Building equipment
as types of windows and doors and their manufacturer, the
elevator type and manufacturer, the mechanical system, and
electrical xtures are also to be identied in this phase.
is kind of information, when taken together, facilitates an
estimate of construction cost. Still, work of every technical
specialist must be coordinated; the public authorities must be
consulted and initial investigations of comfort and environ-
ment should be conrmed.
According to the scope of this work, this phase will be
called as predesign phase.
e data available at this stage enables a better denition
of the structural system. In this stage, it is expected to have
information (drawings) about the plans and elevations of
the building. e detail level of the building enables a much
more accurate denition of the bill of materials. Based on the
available input data, the following aspects need to be fullled
in this stage: a complete bill of materials for the structure and
envelope and the denition of the building orientation.
Figure summarizes the sequence of the phases,
moments, and data improvement of a building project that,
from now on, will be used in this work.
Each phase is characterized by a set of key tasks that lead
to gathering information needed and to the development of
the building architecture and features.
In a conventional design process, these steps can be
understood as a linear process, but sequential work routines
may be unable to support any adequate design optimization
eorts during individual decoupled phases, which of course
lead to higher expenditure. In this approach, the architect
and the client agree on a design concept, consisting of
a general massing schema, orientation, fenestration, and
(usually) the general exterior appearance, in addition to basic
materials. e structural, building physics, mechanical, and
electrical engineers are then asked to implement the design
and to suggest appropriate systems. Although this is vastly
oversimplied, this kind of process is the one that is followed
by the overwhelming majority of general purpose design
On the other hand, a sustainable design needs an inte-
grated design process; it requires the involvement of the
whole design team and the iteration between phases. e
throughout the design process and must work well together
the attitude of the design team is critical and their members
must be able to establish a collaborative framework for the
Although conceptual and predesign phases have been
dened, in this paper, only conceptual phase will be consid-
ered for the inclusion of sustainable concerns. It is considered
to be the most crucial phase, as less data is available and the
possibilities to design and innovate are greater.
3. Selection of Indicators
As mentioned previously in this paper, core indicators aim to
predict the building’s sustainability performance at concep-
impacts, energy, and life cycle costs related indicators were
considered to be those which have a major inuence on sus-
tainability and are able to be assessed at conceptual design
3.1. Environmental Impacts. Environmental impacts category
is composed of one single indicator—aggregated value of envi-
ronmental impact—which in turn gathers the seven subindi-
cators proposed in EN -:, listed in Table .ese
e Scientic World Journal
T : Subindicators describing environmental impact indicator.
Global warming potential, GWP kg COequiv
Depletion potential of the stratospheric ozone layer, ODP kg CFC equiv
Acidication potential of land and water; AP kg SO−equiv
Eutrophication potential, EP kg (PO)−equiv
Formation potential of tropospheric ozone photochemical oxidants, POCP kg ethene equiv
Abiotic resource depletion potential for elements; ADP elements kg Sb equiv
Abiotic resource depletion potential of fossil fuels ADP fossil fuels MJ
T : Indicators describing energy impacts.
Total primary energy demands and share of
renewable and nonrenewable primary energy
resources (in operation phase)
sub-indicators are evaluated based on characterization fac-
tors and input ows.
Normal life cycle impact estimator soware (as SimaPro
or GaBi) can be used to estimate these values. As in the
project conceptual stage the exact amount or construction
technology to be used is under determination, and a database
of the buildings’ envelope elements and its environmental
life cycle impact is needed. A database with this purpose
has already been published by Braganc¸a and Mateus .
It presents environmental life cycle data impact for several
building elements and materials, aiming to support design
decision making towards greater environmental performance
of their buildings. Based on a comparison, the designers will
be able to determine the solutions with less environmental
impact or resource use.
3.2. Energy. Total primary energy demand describes the
energy consumption predicted to the operational phase,
summarized in Tab l e . Guidelines for energy consumption
impose the improvement of energy eciency and the reduc-
tion of consumption [,]. For that reason, the total
demand for primary energy should be minimized and the
share of renewable energy should be maximized while reduc-
ing the share of nonrenewable energy during the building’s
life cycle. is indicator accounts for estimation of (i) energy
use for space heating, (ii) energy use for space cooling, (iii)
energy use for domestic hot water production, and (iv) other
energy uses. To assess energy performance, an algorithm to
compute operational energy at early design stage needs to be
used. National, regional, or local codes of practice for ther-
mal behaviour and energy eciency are most oen simple
calculation procedures that can be easily used to estimate the
energy consumption at the operational phase.
3.3. Life Cycle Cost. e indicators describing life cycle cost
arelistedinTable . Construction costs are all the costs
related to each process needed to build the building. is
indicator includes (i) the cost of material acquisition and
transportation, (ii) the cost of construction equipment, and
T : Indicators describing life cycle costs.
Construction costs C/m
Operation costs C/m
End-of-life costs C/m
(iii) the cost of manpower. Most of these costs are usually
provided in the project. ese costs usually occur in the rst
or second years of the building life cycle. However, due to
the long time period of analysis, it may be assumed that they
occur in the rst year, the base year, of the building life cycle.
Maintenance costs include all costs occurring over the
service life of the building, in order to keep it according to
the required functional conditions. End-of-life costs refer to
the end-of-life activities such as the total or partial demolition
of the building and the removal of the demolition waste to
its nal destination. ese costs may be estimated based on
scenarios and best practices.
us, the authors will take advantage of their team
previous work [,] and the work done by Fuller and
Petersen  and use their approach to implement costs
3.4. Summary of Selected Core Indicators. In order to ease
understanding, Table summarizesthecoreindicatorspro-
posed. As seen above, eleven indicators to be included in the
initial phases of design were selected. e rst seven regard
environmental impact categories, such as global warming
or abiotic resource depletion, which can be easily estimated
through a database or a catalogue of buildings’ elements LCA.
e eighth indicator considers primary energy demand.
Although it may look dicult to assess this indicator at an
early design stage, the use of codes of practice for thermal
behaviour and energy eciency allows simple assessments.
At last, three cost related indicators were considered. All
three represent an estimation of the buildings life cycle costs,
which represent a major aspect to take into account since
early stages. Typically, stakeholders only consider initial costs
neglecting all the other attitudes that may lead to more costly
buildings when looking to its entire life.
e aim of this paper is to determine which sustainable indi-
cators can be assessed in the initial phases of a design project.
e Scientic World Journal
T : List of selected indicators for conceptual phase.
() Global warming potential
() Depletion potential of the stratospheric ozone layer
() Acidication potential of land and water
() Eutrophication potential
() Formation potential of tropospheric ozone photochemical oxidants
() Abiotic resource depletion potential for elements
() Abiotic resource depletion potential of fossil fuels
Energy () Total primary energy demand
Life cycle costs
() Construction costs
() Operation costs
() End-of-life costs
For that, an initial study was carried out to clarify the
contents of the early stages of design of a building. It was
concluded that, although dierent names are given, most of
the available literature identies the same stages. From the
several designations and stages, the following were analysed
in this work:
(i) conceptual phase: it begins when the client meets
the design team and the objectives of the project are
dened. It represents a preliminary design phase of
the building, in which the overall system congura-
tion is dened and schematic drawings and layouts
will provide an early project conguration, type of
architecture, and formal and functional aspects. It
lacks specic data;
(ii) predesign phase: it starts with the implementation of
the working drawings; the general shape of the build-
ing is developed through plans, sections, and eleva-
tions; the provisional information addressed in the
conceptual phase is conrmed or modied.
Several methodologies, standards, and research projects
were analysed to determine the nal set of key indicators
that should be considered in this methodology, supporting
assessing and management of project process during early
e conceptual phase deals with fuzzy data and oen
lacks information, which makes it impossible to address sev-
eral indicators, especially the ones related to the social and
functional aspects of the building.
Taking this into consideration, two groups of indicators
were settled: (i) core indicators and (ii) additional indicators.
Core indicators can be used in the conceptual stage, whereas
additional indicators can only be used in the latter stages
e core indicators regard the aspects that can be
addressed under the little information available at the con-
ceptual phase. On the other hand, additional indicators
compile all the other indicators. In this sense, core indicators
consist in environmental impacts, energy consumption, and
costs, whose data can be obtained from databases of build-
ings’ elements, simple estimation of the operational energy
demands, and databases of construction solutions costs.
In conclusion, from this study, it is essential to consider
sustainability concerns since the rst stages of design project
so as to assure greater performances. Environmental impacts
and life cycle costs are most likely to be easily considered dur-
ing conceptual stage, as they require less information from
specications of the in order to be quantied.
Conflict of Interests
e authors declare that there is no conict of interests
regarding the publication of this paper.
is research work has received partial funding from the
European Community’s Research Fund for Coal and Steel
(RFCS) under Grant Agreement no. RFSR-CT--.
FCT Fellowship SFRH/BD//.
 S. Walter, Sustainable by Design—Explorations in eory and
Practice, Earthscan, London, UK, st edition, .
 ECDGE (European Commission Directorate General XVII for
Energy), A Green Vitruvius: Principles and Practise of Sustain-
able Architectural Design, James & James Science Publishers,
London, UK, .
 M. Deru and P. Torcellini, “Improving sustainability of build-
ings through a performance-based design approach,” in Pro-
ceedings of the 8th World Renewable Energy Congress and Expo,
Denver, Colo, USA, .
 R. Mateus and L. Braganc¸a, “Avaliac¸˜
ao da Sustentabilidade
ao: Desenvolvimento de uma Metodologia para
ao da Sustentabilidade de Soluc¸˜
e Scientic World Journal
in I Congresso Sobre Construc¸˜
avel, Porto, Portugal,
 L. Braganc¸a,H.Koukkari,andR.Mateus,“Sustainabledesign
principles in construction sector,” in Proceedings of the
SB04MED International Conference Sustainable Construction:
Action for Sustainability in the Mediterranean, Athens, Greece,
 L. Braganc¸a and R. Mateus, “Sustainability assessment of build-
ing solutions—a methodological approach,” in Proceedings of
the SB04MED International Conference Sustainable Construc-
tion: Action for Sustainability in the Mediterranean,Athens,
Greece, June .
 L. Braganc¸a,R.Mateus,andH.Koukkari,“Sustainabilityof
constructions—integrated approach to life-time structural
engineering,” in Proceedings of the 1st Workshop of the COST
Action C25 on Assessment of Building Sustainability,Lisbon,
Portugal, September .
 L. Braganc¸a and H. Koukkari, “Sustainability of constructions—
integrated approach to life-time structural engineering,” Pro-
ceedings of the st Workshop of the COST Action C on
Assessment of Building Sustainability, Lisbon, Portugal, Sep-
 L. Braganc¸a,R.Mateus,andH.Koukkari,“Perspectivesof
building sustainability assessment,” in Proceedings of the Inter-
national Conference Portugal SB07: Sustainable Construction,
Materials and Practices—Challenge of the Industry for the New
 L. Braganc¸a and H. Koukkari, “Sustainable construction pro
an optimistic world scenario,” in Proceedings of the Interna-
tional Workshop on Sustainability of Constructions—Integrated
Approach to Life-time Structural Engineering, COST Action C:
–, Timisoara, Romania, October .
 L. Braganc¸a and R. Mateus, “SBTool PT: adaptation of the
global SBTool to the Portuguese context,” in Proceedings of the
International Conference “CESB10”: Central Europe towards Sus-
tainable Building, Prague, Czech Republic, .
 L. Braganc¸a, R. Mateus, and H. Koukkari, “Building sustainabil-
ity assessment,” Sustainability,vol.,no.,pp.–,.
 L. Braganc¸a,H.Koukkari,R.Blocketal.,“Summaryreportof
cooperative activities,” in Proceedings of the COST Action C25,
Sustainability of Constructions—Integrated Approach towards
 L. Braganc¸a, H. Koukkari, R. Blok et al., Eds., Proceedings
of InternAtional Conference on Sustainability of Constructions-
Towards A Better Built Environment. Final Conference of the
COST Action C 25, Gutenberg Press, Innsbruck, Austria, .
 L. Braganc¸a and R. Mateus, Evaluation Guide of the SBToolPT-H
Methodology, iiSBE, Guimar˜
aes, Portugal, .
 R. Mateus and L. Braganc¸a, “Sustainability assessment and
rating of buildings: developing the methodology SBToolPT-H,”
Building and Environment,vol.,no.,pp.–,.
 EN, -:, “Sustainability of construction works—sus-
tainability assessment of buildings—part : general framework,”
CEN/TC , .
 EN, -:, “Sustainability of construction works—
assessment of buildings—part : framework for the assessment
of environmental performance,” CEN/TC, .
 EN, -:, “Sustainability of construction works—sus-
tainability assessment of buildings—part : framework for the
assessment of social performance,” CEN/TC, .
 EN, -:, “Sustainability of construction works—sus-
tainability assessment of building—part : framework for the
assessment of economic performance,” CEN/TC , .
 EN, :, “Sustainability of construction works—assess-
ment of environmental performance of buildings—calculation
method,” CEN/TC , .
 Directive //EC of the European Parliament and of the
Council of December on the energy performance of
 Perfection, “PERFECTION—performance indicators for
health, comfort and safety of the indoor environment,” FP EU
Project Grant number , .
 Super buildings partners, “Sustainability and performance
assessment and benchmarking of buildings,” FP EU Project,
Grant number , http://cic.vtt./superbuildings/.
 OPEN HOUSE, Version .. Reference for Case studies, .
 P. Huovila, “Managing the life cycle requirements of facilities,”
in Proceedings of the Workshop on CIB W078, In-House Pub-
lishing, Rotterdam, e Netherlands, .
construction projects,” International Journal of Project Manage-
 K. R. Bunz, G. P. Henze, and D. K. Tiller, “Survey of sustainable
building design practices in North America, Europe, and Asia,”
Journal of Architectural Engineering,vol.,no.,pp.–,
 Ministry for the Environment—Manat¯
grated Whole Building Design Guidelines, Ministry for the
 A. S. Hanna and M. A. Skington, “Eect of preconstruction
planning eort on sheet metal project performance,” Journal of
Construction Engineering and Management,vol.,no.,pp.
 RIBA (Royal Institute of British Architects), Green Overlay to
RIBA Outline Plan of Work, RIBA Publishing, London, UK,
 O. Wakita and R. Lind, e Professional Practice of Architectural
Wor k i ng Dra w i ngs, John Wiley & Sons, New York, NY, USA, rd
 H. Haroglu, J. Glass, and T. orpe, “A study of professional
perspectives on structural frame selection,” Construction Man-
agement and Economics,vol.,no.,pp.–,.
 S. MacMillan, J. Steele, S. Austin, P. Kirby, and S. Robin, “Devel-
opment and verication of a generic framework for conceptual
design,” Design Studies,vol.,no.,pp.–,.
 N. Kohler and S. Moatt, Life-Cycle Analysis of the Built Envi-
ronment, United Nations Environment Programme Division
of Technology, Industry and Economics Publication, UNEP
Industry and Environment, .
 J. Andrade, S. Vieira, and L. Braganc¸a, “Selection of key sustain-
able indicators to steel buildings in early design phases, in Heli
ıs Braganc¸a, Samir Boudjabeur,” in Proceedings of
the International Workshop on Concepts and Methods for Steel
Intensive Building Projects, ECCS, Munich, Germany, May .
 L. Braganc¸a and R. Mateus, Life-Cycle Analysis of Buildings:
Environmental Impact of Building Elements, iiSBE, Guimar˜
Portugal, , http://hdl.handle.net//.
 World Health Organization, Water, He a l th and E c o s ystem s ,
e Scientic World Journal
 C. Ara´
ujo, M. Almeida, and L. Braganc¸a, “Analysis of some Por-
tuguese thermal regulation parameters,” Energy and Buildings,
vol. , pp. –, .
 S. Fuller and S. Petersen, “Life-cycle costing manual for the
Federal energy management program,” in NIST Handbook,vol.