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The carbon-reduction potential of straw-bale housing
Building Research & Information
Abstract
The role of straw bale as a construction material for reducing the whole-life impacts of housing is examined. The embodied and operational CO 2 emissions in a recently completed UK social housing project are compared using alternative domestic external wall constructions and the effects on the resulting CO2 emissions. It is estimated that over 15 tonnes of CO2 may be stored in biotic materials of each of the semi-detached houses, of which around 6 tonnes are sequestered by straw and the remaining by wood and wood products. This suggests the carbon lock-up potential of renewable construction materials is capable of reducing the case study house's whole-life CO2 emissions of the house over its 60-year design life by 61% when compared with the case without sequestration. The practical implications of construction, detailing, maintenance, cost and self-build potentials of straw-bale construction are also considered. The potential for load-bearing straw-bale walls is examined through the whole-life performance of straw-bale construction with alternative conventional external walling systems.
... It is essential to underline that half of the observed studies, including Ayasgil et al. (2022), Brojan (2013), Cascone et al. (2018), Liu et al. (2020), and Sodagar et al. (2011), assess the environmental and economic aspects separately. This fact may be a significant shortcoming affecting the comprehensiveness and accuracy of the results because the economic and environmental pillars interact harmoniously and depend on one another to survive (Ranjbari et al., 2021). ...
... Despite this limitation, these studies achieve their objectives of highlighting the economic and environmental outperformance of circular bio-based building materials compared to conventional ones. For example, a straw wall house has a lower wholelife environmental impact and construction costs than a traditional house (Sodagar et al., 2011). Likewise, replacing red bricks with lightweight bricks made from oyster shells and sorghum waste can significantly reduce CO2 emissions and lower construction costs (Liu et al., 2020). ...
... This section reports the findings obtained through a systematic analysis, focusing on the different methodological issues emerging from the selected LCA studies, including those that combined LCA with other methods to assess multiple sustainable dimensions. Indeed, LCA is adopted singly (n = 58) and integrated with the MFA (n = 2) to evaluate the environmental dimension or combined with other approaches in four environmental and economic analyses (Brojan, 2013;Sodagar et al., 2011;Torres-Rivas et al., 2018;Torres-Rivas et al., 2021) and two sustainability assessments (Barrio et al., 2021;Joglekar et al., 2018), resulting in a total of 66 LCA-related studies, accounting for nearly 70% of the sample. ...
Using circular bio-based building materials is considered a promising solution to reduce the environmental impacts of the construction industry. To identify the pros and cons of these materials, it is essential to investigate their sustainability performance. However, the previous sustainability assessment studies are heterogeneous regarding the assessment methods and objectives, highlighting the need for a review to identify and analyse these aspects. Moreover, there is still a lack of studies reviewing the methodological issues and implications of the assessment methods, as well as the current end-of-life scenarios and circularity options for these materials. To address these gaps, this study conducts a systematic and critical review of a sample of 97 articles. The results indicate that Life Cycle Assessment (LCA) is the most frequently applied method, yet most studies are cradle-to-gate analyses of materials. Otherwise, very few studies consider the end-of-life phase, and most of the end-of-life scenarios analysed are unsustainable and have low circularity levels. The analysis also highlights the methodological issues of the assessment methods used, with a particular focus on LCA, such as a lack of consensus on system boundaries, functional units, and databases for facilitating sustainability assessments associated with the use of circular bio-based building materials. Two primary recommendations emerge from the analysis. Firstly, for LCA studies, it is recommended to increase transparency and harmonisation in assessments to improve the comparability of results. Besides, to overcome data availability issues, it is recommended to use data from multiple sources and conduct sensitivity and uncertainty analyses. Secondly, more sustainability assessments (including the three pillars) considering the whole life cycle with more sustainable end-of-life scenarios and circularity options for these materials should be conducted.
... The open burning of the related crop residues has contributed to haze pollution in northern China [14]. However, previous case studies had highlighted the carbon lock-up potential of straw bale construction [15][16][17][18], which can reduce whole-life CO 2 emissions by 61% in comparison with the construction using traditional external wall construction [16]. A typical wheat straw bale weighing 16 kg has the capacity to sequester 32 kg of CO 2 through the process of photosynthesis [9]. ...
... The open burning of the related crop residues has contributed to haze pollution in northern China [14]. However, previous case studies had highlighted the carbon lock-up potential of straw bale construction [15][16][17][18], which can reduce whole-life CO 2 emissions by 61% in comparison with the construction using traditional external wall construction [16]. A typical wheat straw bale weighing 16 kg has the capacity to sequester 32 kg of CO 2 through the process of photosynthesis [9]. ...
... Here, timber is treated as another bio-based material which can facilitate carbon emission reduction through carbon sequestration [16]. CLB, AACB and GSHB are traditionally applied material in the region. ...
... environmental impact, respectively (Milutienė et al., 2012). Sodagar et al. (2011) reported that straw bale walls exhibited lower embodied carbon emissions than conventional walls with the same U-value. The global warming potential (GWP) of straw bale walls was 4.32 kg CO 2 /m 2 , indicating significant reductions of 68.6%-92.0% ...
... Cornaro et al. reported that the GWP of straw bale constructions was 705.69 kg CO 2 /m 2 , reduced by 35.97 kg CO 2 /m 2 compared to conventional walls during the phase of production, construction and a service life of over 50 years (Cornaro et al., 2020). Sodagar et al. (2011) reported a lower GWP of 603.6 kg CO 2 /m 2 for straw bale constructions over a 60-year life cycle, with reductions ranging from 14.7 kg CO 2 /m 2 to 77.6 kg CO 2 /m 2 compared to engineering-timber frame, brick-clad timber frame, rendered masonry, and brick-faced masonry, respectively (Sodagar et al., 2011). ...
... Cornaro et al. reported that the GWP of straw bale constructions was 705.69 kg CO 2 /m 2 , reduced by 35.97 kg CO 2 /m 2 compared to conventional walls during the phase of production, construction and a service life of over 50 years (Cornaro et al., 2020). Sodagar et al. (2011) reported a lower GWP of 603.6 kg CO 2 /m 2 for straw bale constructions over a 60-year life cycle, with reductions ranging from 14.7 kg CO 2 /m 2 to 77.6 kg CO 2 /m 2 compared to engineering-timber frame, brick-clad timber frame, rendered masonry, and brick-faced masonry, respectively (Sodagar et al., 2011). ...
... Although collaborative housing in Europe has received considerable attention in recent years [1][2][3], scant attention has been given to the study of the informal housing sector and the role of self-help housing in the United States [4][5][6][7]. Research that draws a connection between straw bale building code and self-help housing is even rarer, with only one article detected from a case study of a low-income housing project in the United Kingdom [8]. This is understandable given that the only mutual self-help housing program in the United States involving straw bale building methods was found in Moab, Utah. ...
... Energy-efficient housing and contemporary net-zero homes are gaining popularity in residential planning throughout the world [23], including the U.S. [24] and South Korea [25], though few studies focus on the importance of straw bale construction. Whole-life CO 2 emissions of a low-income house in the U.K. using straw bale walls over its 60-year design life were found to be reduced by more than 60% when compared to conventional walls [8]. ...
... In addition to providing quality housing at affordable rates for lower-income individuals and households, CR homes are arguably more energy-efficient than conventional low-income housing. As previously noted, the use of straw bales in exterior wall construction has been shown to increase R-values (insulation values) and reduce overall carbon emissions [8,28]. Additionally, CR homes have significantly lower embodied carbon levels when compared to conventional homes built through other self-help housing programs. ...
Central to this housing program evaluation and policy analysis is the need to clarify competing definitions of self-help housing and to delineate the role of straw bale building in creating more sustainable, subsidized housing programs. Straw bale home construction is shown to be achieved at a lower cost, with lower embodied carbon than conventional housing, yet the building technique is not widely practiced as part of government-assisted housing, internationally, nor among mutual self-help housing (MSHH) programs in the United States, due in part to limitations of code adoption. Community Rebuilds, a federally subsidized MSHH program in Moab, Utah, is compared to other self-help housing programs in the state and stands apart with current “living building” development. Interviews and survey results from Community Rebuilds staff, contractors, and homeowners provide qualitative insights regarding the value of social capital, and embodied carbon calculations were used to assess the sustainability of conventional versus natural building methods and materials. Results confirm the need for increasing straw bale building code adoption and the creation of more sustainable self-help housing options in the U.S. and abroad.
... Several studies [93][94][95] have been done to compare the environment impact of straw bale building with different insulation materials and construction technique. Milutienė et al. [93] compared normalized environmental impact of different load-bearing and thermal insulation materials (Fig. 17) shows straw bales has the least environmental impact compared to other insulation materials (mineral wool, cellulose fiber, polystyrene, etc.), and only seconded to light clay brick as load bearing structure compared to sawn timber, concrete or sand-lime brick. ...
... In another LCA study, Sodagar et al. [94] compared a lime plastered straw bale wall with different configuration of wall (timber framed and masonry) and insulation materials (wood fiber, mineral wool), the result shows a lower global warming potential (GWP) of straw bale house (604 kgCO2 eq•m-2 over 60 years) compared to other configurations (e.g. 618 kgCO2 eq•m-2 for engineering timber frame), and a better performance if also consider the carbon sequestration factor (Fig. 18). ...
... 618 kgCO2 eq•m-2 for engineering timber frame), and a better performance if also consider the carbon sequestration factor (Fig. 18). Using the energy performance data of straw bale buildings in different field studies (Fig. 14) and Sodagar et al. [94], Fig. 19 shows their annual operational CO2 emissions, calculated based on the average household energy demand and respective national grid electricity performance. In overall the annual in-use energy and associated CO2 emission of straw bale buildings are lower than the impacts from average household in Europe. ...
Straw bale constructions are considered as a promising solution towards the goal of decarbonisation of building sector. In particular, its use as an alternative thermal insulation and load-bearing material has been promoted. This study provide a thorough review of material properties of straw bale including mechanical, thermophysical and hygric. Furthermore, mechanical, hygrothermal, energy and acoustical performance as well as life cycle assessment of straw bale constructions are reviewed and discussed. The critical evaluation of the recent research confirms that straw bales can provide satisfactory results as thermal insulation material compared to conventional materials, while in parallel reflects a high potential for constructions with low embodied emissions. The potential of straw bale is tackled by the lack of consistent representation of material properties, which is controversial to the significant amount of the relevant scientific results that have been reported during the last years. This review provides a systematic framework that can function as basis for future research on straw bales as building material.
... This adds significantly to the uncertainty of the results (H€ akkinen and Haapio, 2013;Peñaloza et al., 2016). Generally, lower estimates have been suggested for wood products (Buchanan and Levine 1999;Upton et al., 2008;Salazar and Meil, 2009;n N€ ass en et al., 2012;and Peñaloza et al., 2016), straw bales (Sodagar et al., 2011) and hempcrete (Arrigoni et al., 2017), than for concrete and metal components. Nevertheless, it bears mentioning that different building components have higher carbon emissions during the processing and transport phases than is initially accounted for in embodied energy measurements. ...
... In this study, the average value of these two studies, 0.78 kg of CO 2 , was applied. In terms of the carbon storage capacities of timber, numerous studies were reviewed (Boutin et al., 2006, Abbott, 2008, Sodagar et al., 2011, Vogtl€ ander et al., 2014, and GaBi database/PE-international, 2015. Based on the estimated average value, timber has a negative cradle-to-gate carbon footprint of 1.25 KgCO 2 / kg. ...
... Based on the estimated average value, timber has a negative cradle-to-gate carbon footprint of 1.25 KgCO 2 / kg. The total CO2 sequestered in straw is 1.35 KgCO 2 /kg, based on research conducted by Atkinson (2008) and Sodagar et al. (2011). ...
Purpose
Over the last eight years, the Middle East has experienced a series of high profile conflicts which have resulted in over 5.6 million Syrians forced to migrate to neighbouring countries within the MENA (Middle East and North Africa) region or to Europe. That have exerted huge pressure on hosting countries trying to accommodate refugees in decent shelters and in quick manner. Temporary shelters normally carry a high environmental burden due to their short lifespan, and the majority are fabricated from industrialised materials. This study assesses the carbon impact for a minus carbon experimental refugee house in Sweden using life cycle assessment (LCA) as tool. SimaPro and GaBi software were used for the calculations and the ReCiPe midpoint method for impact assessment. The results show that using local plant-based materials such as straw, reeds and wood, together with clay dug from close to the construction site, can drastically reduce the carbon footprint of temporary shelters and even attain a negative carbon impact of 226.2 kg CO2 eq/m2. Based on the results of the uncertainty importance analysis, the overall global warming potential impact without and with sequestration potential are mostly sensitive to the variability of the GWP impact of wood fibre insulation.
Design/methodology/approach
The methodology is designed to calculate the GWP impact of the refugee house over its entire life cycle (production, operation and maintenance and end of life). Then, the sensitivity analysis was performed to explore the impact of input uncertainties (selection of material from the database and the method) on the total GWP impact of the refugee house with and without sequestration. The ISO standards (International Standard 14040 2006; International Standard 14044 2006) divide the LCA framework into four steps of Goal and scope, inventory analysis, impact assessment, and interpretation.
Findings
This study has shown an example for proof of concept for a low impact refugee house prototype using straw, reeds, clay, lime and wood as the principle raw materials for building construction. Using natural materials, especially plant-based fibres, as the main construction materials, proved to achieve a minus carbon outcome over the life cycle of the building. The GWP of the shelter house without and with sequestration are found to be 254.7 kg CO 2 eq/m ² and -226.2 kg CO2 eq/m2, respectively.
Originality/value
As there are still very few studies concerned with the environmental impact of temporary refugee housing, this study contributes to the pool of knowledge by introducing a complete LCA calculation for a physical house prototype as a proof of concept on how using low impact raw materials for construction combined with passive solutions for heating and cooling can reach a minus carbon outcome. The GWP of the shelter house without and with sequestration are found to be 254.7 kg CO2 eq/m2 and -226.2 kg CO2 eq/m2.
... It can be calculated through stoichiometry that 1 kg of carbon sequestered in the straw stems requires the removal of 3.67 kg of CO 2 from the atmosphere. This amount of adsorbed carbon will not be released into the atmosphere until the straw bale buildings are demolished [29]. ...
... Considering the property differences of straw bales in different researches [40,50,51], the thermal conductivity of straw bale is designated as 0.700 W/mK. Existing researches confirmed the high thermal mass of straw bale walls [29,52] with specific thermal heat capacity ranging from 1388-2000 J/(kgK) [53,54]. As a result, the heat capacity of the PSBC is designated as 2000 J/(kgK) in the simulation process. ...
... Due to the limited research on carbon emissions of rice straw and wheat straw regarding the conditions in China, the overall carbon emissions of PSBC walls may not be assessed in detail. However, considering that the straw is a byproduct of agricultural activities, the carbon emissions of straw would be significantly lower than those of other building materials [29]. ...
The Prefabricated Straw Bale Construction (PSBC) has been proven as one of the most efficient construction methods to achieve low-energy buildings with low environmental impacts. This research presents analysis of the rationale for using straw bale constructions in northern China and a discussion of feasible constructions of PSBC to meet the local building codes following evaluations of potential energy performance of domestic buildings with PSBC in severe cold regions and cold regions in China. The results show that the buildings with PSBC reduce both heating and cooling energy uses, as well as heating intensities across the severe cold and cold regions, compared to the domestic buildings with conventional constructions. The findings of this research will contribute to reducing energy consumption in building industries in China.
... Figure 2 shows that the materials in the categories 'biomass -fast growing' and 'biomass -slow growing' have the highest CO2 storage potential according to the literature. Reviewed materials for the category 'biomass -fast growing' are straw, hemp and bamboo but also miscanthus, sheep wool, herbaceous plants, moso bamboo, palm leaves and seaweed, as reported in the studies by [8][9][10][11][12][13][14][15]. An interesting new approach for growing microalgae in a CO2 off-gas stream with a CO2 storage potential of 2000 gCO2/kg is also included in this category. ...
... The category 'biomass -slow growing' contains materials like wood or timber but also cellulose fibre, cork, cardboard and construction paper. The values for the materials in this category have been reported by [8,10,[13][14][15]. The CO2 storage ranges reported for both biomass categories appear to be very similar. ...
This study assesses the carbon dioxide storage ranges within new and innovative building materials. We conduct a Systematic Literature Review and gather data for carbon dioxide storage in building materials from 27 studies. The obtained values are classified into derived Eurostat categories ‘biomass - fast growing’, ‘biomass - slow growing’, ‘non-metallic minerals - industrial’ and ‘non-metallic minerals - natural’ and harmonized to the unit of gram carbon dioxide storage per kilogram of material (gCO 2 /kg). Based on the systematic review, the mean value of carbon dioxide storage for the category ‘biomass - fast growing’ results in 1758.0 gCO 2 /kg and for the category ‘biomass - slow growing’ in 1787.0 gCO 2 /kg, while the mean value for ‘non-metallic minerals - industrial’ results in 137.7 gCO 2 /kg and for ‘non-metallic minerals - natural’ in 574.1 gCO 2 /kg. The obtained statistical summaries provide a basis for future research on the path towards a net-zero carbon built environment.
... Only one study simultaneously assesses economic and environmental aspects at the component scale using LCA and SCA methods [94]. These approaches are also adopted by Sodagar et al. [78] at the building scale. Meanwhile, EPA and SCA approaches are utilised by Krasny et al. [61] and Cascone et al. [82] to evaluate the environmental and economic performance of circular bio-based buildings. ...
... Vazquez et al.[76] apply LCA under the lens of the Environmental Product Declaration approach. Meanwhile, at the building scale, Shang and Tariku[63], Florentin et al.[77], and Sodagar et al.[78] use subforms of LCA, such as Life-Cycle Energy Assessment and Life-Cycle Carbon Emissions Assessment. Nonetheless, using the LCA methodology to assess the climate change impact of bio-based materials may have limitations. ...
Circular bio-based building materials are “materials wholly or partly derived from renewable biological origins, or by-products and biowaste of plant and/or animal biomass that can be used as raw building materials and decorating items in construction, in their original forms or after being reprocessed”. Literature shows that using these materials can represent a coherent solution to mitigate the climate impacts of the building sector according to the circular economy model. However, previous studies are fragmented due to the heterogeneity in the studied material types, scales of case studies, and sustainability assessment methods applied. Therefore, this systematic and bibliometric literature review of 97 articles aims to categorise case studies, review the state-of-the-art of sustainability assessment of case studies and highlight the pros and cons of circular bio-based building materials. Results indicate that the material scale is the most researched compared to the other scales. Environmental analysis, primarily employing life cycle assessment, is the most frequently researched, followed by economic analysis, while social impact research is still in an early stage. Concerning the pros and cons, circular bio-based building materials outperform traditional materials in reducing initial production costs and mitigating environmental impacts, especially climate change and abiotic resource use. However, some materials perform worse in categories like eutrophication, land use, etc., and may not be economically viable from an entire life cycle perspective.
... Mit Blick auf die spezifischen Transportwege ist jedes Bauprojekt gesondert zu betrachten. In Vergleichsstudien ist das Stroh herausragend [6,28] Zahlreiche regionale Ökobilanzen nachwachsender agrarischer Rohstoffe liegen vor. Ein Beispiel: Im spanischen Valencia werden rd. ...
... Ähnlich vorteilhaft wird der Massivbau mit Strohballen bewertet [30]. Für Strohballenhäuser wurde eine um 61 % verringerte Treibhausgasbilanz über einen 60-jährigen Gebäudelebenszyklus berechnet, im Vergleich mit einem auf übliche Weise massiv errichteten Haus [28]. Ob im Sinne der Klimagerechtigkeit Stroh oder etwa besser Sägespäne als Zuschlagstoff für Lehmziegel verwendet werden sollten, hängt entscheidend von den konkreten Transportwegen ab [31]. ...
Der Holzbau für Hunderte Millionen Menschen soll im Zuge der globalen Klimaschutzpolitik eine zentrale Rolle als Kohlenstoffsenke spielen. Nachwachsende Rohstoffe aus landwirtschaftlicher Produktion werden in diesem Zusammenhang noch kaum diskutiert. Dabei gibt es Gründe dafür: Getreide oder Gräser wachsen je Hektar meist schneller auf als Waldbäume. Baustoffe aus ihnen weisen insgesamt oft bessere Treibhausgasbilanzen auf. Derzeit werden Gräser, Feldreststoffe oder Pappeln aus landwirtschaftlichen Kurzumtriebsplantagen (KUP) noch in hohem Maße energetisch verwertet. Dadurch wird der in der Biomasse gebundene Kohlenstoff wieder freigesetzt. Solche agrarische Biomasse könnte deutlich vermehrt im Bau genutzt werden, was den Lebenszyklus der nachwachsenden Rohstoffe über Jahrzehnte verlängern könnte und höhere Wertschöpfung für die landwirtschaftliche Erzeugung verspricht. Damit dies gelingen kann, bräuchte es aber einen Dialog darüber in der gesamten Wertschöpfungskette, vom Landwirtschaftsbetrieb bis zum Bauunternehmen und Bauherren/Endkunden, um historisch gewachsene Pfade und Verwertungsstrukturen infrage zu stellen und – mit allen wirtschaftlichen Risiken – aufzubrechen. Der Ausbau der Rohstoffbasis unterliegt jedoch agrarökologischen Einschränkungen und einem Vorrang der Nahrungsmittelerzeugung.
Aus: NBau. Nachhaltig Bauen.
Link: https://www.nbau.org/2023/05/02/agrarische-biomasse-fur-den-klimagerechten-bau/
... Research indicates that each semi-detached straw-bale house can store over 15 tons of carbon dioxide, with straw accounting for about 6 tons and wood and wood products for the rest. This implies that renewable construction materials have a high carbon lock-up potential, which can lower the whole-life carbon dioxide emissions of the case study house by 61% over its 60-year design life, relative to the case without carbon sequestration [69]. Another study also demonstrates that, in contrast to the reference rural houses, straw-bale houses with wood or light-steel structures can slash net carbon emissions by 96.75% and 76.92%, respectively [71]. ...
... While there has been a steady stream of research on various products such as chemical fertilizers and biomass fuels in the following twenty to thirty years, this paper does not focus on these topics. Since the first suggestion of the advantages of straw materials in reducing emissions, research in the field of straw has been further investigated in terms of greenhouse gas emissions and renewable energy [69,106]. The implicit energy issues included in all aspects of transportation, construction, and production throughout the construction process have sparked the research on systemic issues in this field [88,107]. ...
The need to effectively control and reduce energy consumption in buildings has become a global concern, prompting an increasing number of studies on the energy efficiency of straw buildings. However, previous review articles on straw research have primarily focused on fragmented material properties such as thermal insulation and mechanical strength and have lacked a comprehensive review of straw materials in building energy efficiency, as well as a thorough analysis of the development lineage of straw building materials. To fill this research gap, this study conducted a bibliometric analysis of 338 papers on the energy efficiency of straw materials published in the WOS core database between 1992 and 2022. The study constructed and visualized multifaceted co-occurrence networks representing the research literature on the energy efficiency of straw building materials, providing a comprehensive understanding of current research efforts, development trends, hot research directions, and the development lineage of this field since 1992. The study’s conclusions suggest that the next research hotspots in this area will be the whole life-cycle of straw materials and their compounding, performance, and application to construction. By tracing the development lineage and clarifying the relationship between the macroscopic building environment and microscopic straw materials, this study offers better predictions of the future development prospects of straw buildings. These findings provide researchers with valuable insights into current research efforts and future research directions in this field, while also serving as a reference for governments seeking to formulate relevant policies for the energy-efficient design of buildings made of straw materials.
... In the present economic climate, customer demand for low-carbon housing integrating industry by-products is still limited, but it is anticipated that low-carbon housing will be a growing market in the near future [24÷26]. As Sodagar [24] estimates, around six tons of CO2 are sequestered by straw as biotic material in a standard semi-detached, two-story and threebedroomed house, with gross area of 85.75 m 2 . Moreover, another nine tones are stored as wood and wood products. ...
... Moreover, another nine tones are stored as wood and wood products. Therefore, the carbon lock-up potential of such innovative designs making use of renewable construction materials is suggested to reduce the case study house's whole-life CO2 emissions over its 60-year design life by 61% compared with a similar house made from usual materials [24]. ...
Full paper at Romanian Journal of Materials (Open Access Journal): https://solacolu.chim.upb.ro/pg66-74.pdf
The construction industry uses an ever-increasing amount of thermal insulation materials to meet the building sector's growing energy efficiency demands. Exclusive use of synthetic thermal insulation may lead to a complicated process of re-integrate demolition waste in the economy and potential environmental damage over time. The use of traditional natural materials is ecological and through an appropriate design of the buildings, it offers efficient construction elements. This paper attempts to increase the professionals' awareness of some typical industry by-products (straw, sawdust, cellulose), with thermophysical characteristics interesting for the building sector. Besides the information needed for the usual engineering calculation, like thermal conductivity coefficient, we measured data needed for dynamic building simulation, such as thermal diffusivity, volumetric heat capacity, and specific heat capacity.
The products tested in this study are:
- finely chopped straws (Fig. 1), an agricultural waste from the Triticale family, having the stem cleaned from impurities like dust or dirt and partially broken as a result of an intense
mechanically process which is necessary to cut the straws at lengths between 2 ÷ 5 cm;
- coarse cut straws (Fig. 2), which are from the same Triticale family, but from a different batch than finely chopped straws, without the inclusion of parasitic weeds. The coarse cut straws are less processed, with a length between 10 ÷ 15 cm and a relatively intact stem.
- fine sawdust (Fig. 3) from softwoods like firs (genus Abies), pine (genus Pinus) or spruce
(genus Picea), currently a by-product of sawmills;
- wood shavings (Fig. 4) from softwoods, currently a by-product of woodworking;
- cellulose (Fig. 4) could be a by-product of different industries. Particularly for this research, we used a product that is considered waste by the tobacco industry, consisting mostly from cellulose acetate (from shattered cigarette filters) and a low percentage of fine shredded thin cigarette paper.
Full paper at Romanian Journal of Materials (Open Access Journal): https://solacolu.chim.upb.ro/pg66-74.pdf
... where: GWP j is the end-of-life embodied carbon for the j-th building system analyzed (kg CO 2eq ); GWP i is the end-of-life embodied carbon for the i-th material or component used in the j-th building system (kg CO 2eq /kg). Taking into account the expressions (3) and (4) also used in some case studies for the analytical determination of EE and GWP [31][32][33], the GWP and EE of the two building systems (XLAM and MBP) were calculated of the housing module considered. The reference studies aimed at the analytical determination of GWP and EE are carried out with dwellings of 100 m 2 whose life cycle is assumed to be 30 years. ...
... The reference studies aimed at the analytical determination of GWP and EE are carried out with dwellings of 100 m 2 whose life cycle is assumed to be 30 years. From the scientific evidence of the authors Asdrubali (2015), Gonzalez and Fugler (2002), Sodagar (2011) relating to the estimation of GWP and EE for dwellings of 100 m 2 , numerical reference parameters are derived for the dwellings subjects of this case study. The GWP and EE values for the two building systems under investigation are collected in Table 8. ...
The International Energy Agency (2019) states 40% of CO2 emissions in cities are linked to the buildings stock, in particular to heating and cooling systems, material types and users’ performance. According to Green New Deal, the energy transition of buildings is becoming a priority. This is via investments with low environmental impacts through renewable energy sources. The paper describes an integrated economic-energy-environmental framework (IE³F), i.e., an economic evaluation protocol for new constructions and/or existing renewal projects aimed at supporting the choice phase between alternative technological solutions based on biocompatible materials. The IE³F borrows the logical-operative flow of the life cycle assessment multi-criteria approach. The value aspects translated into monetary terms that characterize the project life cycle are taken into account. The protocol was tested on an emergency project in Italy, namely in Messina City. The results obtained provide evidence of the versatile use of IE³F and its practical utility to guide economic convenience judgements on building investments and choice problems between alternatives in sustainable perspective. The research deepening will be about keeping track of multiple performance levels of the construction, not only the energy performance, and attempting to estimate the corresponding economic value in terms of increase/decrease of construction cost value.
... 2017; Ghisellini et al., 2018;Nußholz et al., 2019;Andersen et al., 2020), design for disassembly (Densley Tingley and Davison, 2012;Eberhardt et al., 2019), renovating rather than building new and using more wood in construction (Salazar and Meil, 2009;Sodagar et al., 2011;Carcassi et al., 2020;Churkina et al., 2020). ...
... In this study, "sufficient information" was defined as information on the built area, the reference study period and the total embodied GHG emissions. From the in-depth analysis, 79 papers and reports were found relevant (Salazar and Meil, 2009;Sodagar et al., 2011;Hoxha et al., 2020), (Buchanan and Honey, 1994; Most of the collected papers and reports examine a number of different scenarios. For instance, papers and reports may assess different scenarios that vary in building types, biogenic carbon approaches (i.e. ...
Buildings play a vital role in reaching the targets stated by the Intergovernmental Panel on Climate Change to limit global warming to 1.5 degrees. Increasing the use of wood in construction is a proposed upcoming strategy to reduce the embodied greenhouse gas emissions of buildings. This study examines existing life cycle assessments of wooden buildings. The aim is to investigate embodied greenhouse gas emission results reported, as well as methodological approaches applied in existing literature. The study applies the protocol for Systematic Literature Reviews and finds 79 relevant papers. From the final sample, the study analyses 226 different scenarios in-depth in terms of embodied emissions, life cycle assessment method, life cycle inventory modelling and biogenic carbon approach. The analysis shows that the average reported values of embodied greenhouse gas emissions of wooden buildings are one-third to half of the embodied emissions reported from buildings in general. Additionally, from the analysis of the final sample we find that the majority of wooden building life cycle assessments apply similar methods and often leave out biogenic carbon from the assessment or simply do not declare it. This implies that the focus on variability in the different methods applied in wooden building life cycle assessments needs to be increased to establish the relationship between methodological choices and embodied emissions of wooden buildings. Further, transparency and conformity in biogenic carbon accounting in life cycle assessments is essential to enhance comparability between life cycle assessment studies and to avoid distortions in embodied GHG emission results.
... Although these values consider the carbon offset of natural building materials, rural houses built with non-conventional methods have a better environmental performance even without accounting for the carbon sink effect. The importance of carbon offsetting is highlighted by the results of Sodagar et al. (2011) since it provides a net positive environmental effect after considering carbon sink, which means that it is environmentally beneficial to build a straw bale house. ...
... Crop cycles of wheat and rice span less than a year, making them promising bio-based building materials. Wheat straw bales often absorb around 1.35 kg of carbon dioxide per kg of body weight [64]. According to the GWPbio figures, each kind of raw material and biological carbon repository can be used to quantify the effects of the carbon cycle [65]. ...
Over the past decade, the concept of a circular economy has increasingly gained attention as a framework for guiding businesses and policymakers. Given its significant environmental impact, the building industry plays a pivotal role in the transition toward a circular economy. To address this, our review proposes a bio-based building material, specifically straw bale, which elaborates on the circularity of bio-based buildings based on the 3R principles of a circular economy: reduce, reuse, and recycle. In terms of the “reduce” principle, straw-bale buildings can reduce construction waste, the environmental impact, energy requirements, and carbon emissions. Regarding the “reuse” principle, straw-bale buildings utilize agricultural waste resources and are easily disassembled due to their prefabrication. As for the “recycle” principle, straw-bale buildings can undergo physical, biological, and biochemical conversion processes (thermochemical conversion), yielding both wooden composite boards and potential biogas and biomass fuels for electricity and heating. This study evaluates the contribution of straw packaging construction and the use of straw as a raw material, using the 3R principles to determine future research opportunities for the construction industry to achieve a circular economy. The results of this study offer circular economy solutions and interdisciplinary research insights for researchers and practitioners interested in the building environment.
... Such materials have high embodied GHG emissions due to their carbon-intensive production process and are not able to regulate humidity leading to low summer heat comfort 37 . Alternatives such as straw or hemp have been developed for decades [38][39][40][41] but are recently gaining scientific and industrial credibility [42][43][44] , probably linked with the climate collapse approaching. Indeed, it is possible to renovate buildings with either external or internal insulation made of straw or hemp 45,46 . ...
Building renovation is urgently required to reduce the environmental impact associated with the building stock. Typically, building renovation is performed by envelope insulation and/or changing the fossil-based heating system. The goal of this paper is to provide strategies for robust renovation considering uncertainties on the future evolution of climate, energy grid, and user behaviors, amongst others by applying life cycle assessment and life cycle cost analysis. The study includes identifying optimal renovation options for the envelope and heating systems for building representatives from all construction periods that are currently in need of renovation in Switzerland. The findings emphasize the paramount importance of heating system replacements across all construction periods. Notably, when incorporating bio-based insulation materials, a balance emerges between environmental impact reduction and low energy operation costs. This facilitates robust, equitable, and low-carbon transformations in Switzerland and similar Northern European contexts while avoiding a carbon spike due to the embodied carbon of the renovation.
... Further work may expand the sampling method to seek out radical practice beyond the scope of mainstream architectural recognition. This may include a consideration of communities who simultaneously embrace innovative technologies combined with low impact lifestyles (19). The greatest benefit to the use of straw in construction is its potential associated with embodied energy and minimal impact on the environment across its life cycle. ...
... bio-based materials. 47 48 Increasing the use of wood in buildings has gained considerable attention due to its inherent 49 ecological advantages [ types of structural frames in timber and reinforced concrete and found that concrete alternatives 55 may have up to 52% increased embodied GHG emissions compared to the timber alternatives. 56 ...
... Prefabricated straw-bale walls with load-bearing structural timber components, for instance, have shown to dispose of a high carbon storage potential over relatively long lifetimes, see e.g. [93,94]. This example underlines that the influence of nonstructural building components is to be kept in mind when the aim is to obtain a more holistic comparison of the embodied carbon in buildings with different structural types and materials. ...
Embodied emissions in construction materials make a relevant contribution to carbon emissions worldwide. While this has been broadly recognised, only little attention has been paid to the role of load-bearing structures in this regard, and if so, mainly limited to assessments of individual structures. For analysing the global warming impact of engineering structures in a wider context, dynamic material flow analysis is deployed in this study. The future stocks and flows of structural materials and their associated embodied emissions in German residential buildings are quantified based on a mass-balance consistent multi-layer model, which relates the stocks in use, their inputs, outputs and determinants, such as the building lifetime, the population or the useful building floor area per capita. A scenario analysis under combination of different emission mitigation measures is performed, among them a gradual replacement of the comparatively large masonry structure stock share by timber structures, and a general downsizing of structural material quantities. The results show that when applied to a realistic extent, such measures could contribute with about 4% to 8% to the German average target mitigation rate required for achieving emission neutrality in 2045.
... Venkatarama Reddy and Prasanna Kumar (2010) compared rammed earth walls with concrete walls in built projects in India and found that the embodied carbon could vary between 75% and 85%. Sodagar et al. (2011) focused on the use of straw-bale materials in semidetached houses and discovered that life cycle embodied carbon emissions could be reduced by 61%. Venkatarama Reddy and Prasanna Kumar (2010) also indicated that using mud brick to replace clay brick could reduce emissions by 60%. ...
Compared with well-studied techniques for reducing operational carbon in the building industry, studies on strategies for reducing embodied carbon, as well as their effectiveness, are limited. Therefore, this article aims to address this gap by conducting a systematic review, bibliometric analysis, and meta-analysis of the available evidence to answer the following research questions: What tested and validated mit-igation strategies and techniques exist? What are their effectiveness and suitable application? Initially, 410 publications were found, and 21 articles were reviewed systematically in the fields of embodied carbon mitigation and reduction. In total, 19 mitigation strategies in four categories were identified from the existing literature, which were discussed through a meta-analysis on the available data. The four categories are design optimization, material optimization, construction optimization, and infrastructure optimization. The results revealed that no single mit-igation strategy alone can tackle the problem; rather, an integrated and combined approach is necessary. The meta-analysis indicated that the most effective techniques are within the design optimization (an average 37% reduction) and material optimization categories (an average 37% reduction). The review also revealed the incomplete nature of the reduction assessment from a life cycle perspective. Most studies assess only the material and manufacturing stages, often completely overlooking embodied emissions occurring during the construction, use stage, and end-of-life stage; therefore, the accuracy and comprehensiveness of such study results are questionable.
... Refs. [43,44] claimed that clay used as wall plaster had large levels of reactivity with the ozone and also the lowest 'ozone-initiated reaction product emissions' in comparison to its non-green building counterparts. Ref. [39] expanded on clay plaster comparisons by identifying the results from their testing display that showed that the environmental performance of clay is exceptionally superior to that of standard wall plasters because its production is based on straightforward processes that use small amounts of energy. ...
Green building materials have nontoxic properties and are made from recycled materials. This means they are, in most cases, created from renewable resources in comparison to non-renewable resources. This research aims to further improve the justification of green buildings and their materials. This is undertaken to determine the validity of such construction techniques. This research utilizes both qualitative and quantitative methods through five Australian case studies. The case studies, which are based on new and redeveloped structures, are selected via different geological locations and are evaluated via logical argumentation along with correlation research. Further, the research will address the problem by identifying a variety of green building materials that can be used to substitute non-green building materials. With careful comparisons among the five buildings, the green signs and implementation advantages and disadvantages will be evaluated. The result of this comparison will assist in improving the current education around the topic of green building and benefit the overall response to positive change within the construction industry. Although green building initiatives are not difficult to apply, they can be cost efficient. To maximize their cost efficiency, these initiatives need to be fully adopted. This includes the adaptation of specific building orientation, design, and sealing off penetrations to greatly improve passive heating and cooling. Further, the use of rainwater tanks also assists with energy efficiency by reducing the amount of mains water used. The utilization of natural lighting along with an advanced solar power system would further reduce the overall energy usage.
... Half a century later, "green" building, or more specific "natural" building continues to evolve to greater sophistication since one of the oldest known straw bale homes was built in Nebraska around 1900. More sustainable, or "regenerative" architecture focused on embodied energy of varying building materials, expressed as carbon emissions associated specifically with straw bale building has limited earlier study [12], yet the detailed analysis of natural building methods is rapidly expanding [13,14]. ...
... The utilization of natural resources in the building industry contributes to an enhancement of ecological effects through the following [29]: ...
The motivation for research to help address climate change is a continuous process of searching for eco-friendly materials in the building industry, which will allow minimizing the negative impact of this sector on the environment. The main objective of the paper is to assess the properties of a natural resource such as straw as an eco-friendly material in various variants for use in low-energy demand construction. The research results will fill the knowledge gap in the field of numerical analyses of the energy demand of straw material buildings based on the results of the conducted laboratory tests. A test of a heat transfer coefficient was conducted with different orientation of straw stalks. Then, samples were subject to a fire resistance test to determine material behavior at 1000 °C. During the fire resistance test, the clay-based plaster was ‘burnt out’, which hardened its structure, effectively preventing flames from reaching the insulation layers in the form of straw stalks. As a result of shrinkage (no plaster mesh), the plaster cracked and turned brick-red in color. The insulation layer of straw under the plaster was charred to a depth of 3.0 mm due to the high temperature. However, when the torch was turned off, no fire spread was observed in any layer of the sample. The 3D models of the buildings were created for different eco-friendly materials applied to make external walls. The results of numerical simulation allowed determining the amount of final energy needed to heat the designed building at the level of 26.38 (kWh/m²·year). Conclusions of the above-mentioned tests indicate very good thermal insulating properties determined using the lambda coefficient of 0.069 (W/m·K) and the possible application of straw bales as an alternative for conventional construction. Research has proven that it is possible to construct a building with low energy requirements using natural, easily available waste and completely biodegradable material.
... All existing types of ecological labels are based on the LCA, as well as the calculation of the CO 2 emitted by a product or service throughout its life (Carbon Footprint). Therefore, this research focuses on the quantitative and environmental aspect related to life cycle analysis of C&DW according to ISO 14040:2006(ISO 14040, 2006), ISO 14044:2006(ISO 14044, 2006) and EN 15643-1:2010, 2010(Peuportier et al., 2013Sartori and Hestnes, 2007;Sodagar et al., 2011;Tae et al., 2011;Wu et al., 2012). In detail, in the present research five concrete mixtures with very similar mechanical and workability properties were compared to evaluate the environmental impacts. ...
Ensure sustainable consumption and production patterns requires urgent actions to combat climate change and its impacts as established by Sustainable Development Goals (SDGs). In this context, this study demonstrates the feasibility to produce structural concrete using recycled aggregates from construction and demolition waste in Italy. More specifically, the present research aims to analyze the environmental impacts caused by five mixtures of concrete, with similar mechanical properties and workability, but with a different amount of recycled coarse aggregate and natural coarse aggregate (0% - 30% - 50% - 70% - 100%). Fixed plant and a mobile plant treatments are investigated as two different modes of production of recycled aggregates. Life Cycle Assessment (LCA) methodology is applied to achieve this goal. The main results demonstrate that mixtures formed by recycled coarse aggregates have a better environmental impacts than the only one formed exclusively by natural coarse aggregates and results improve when the amount of recycled coarse aggregate is higher.
... The recent years' trend in the European Union has been to move in the direction of "zero carbon" buildings and Sodagar (Sodagar et al., 2011) appreciate this would be a growing market in the near future, even though there are still many barriers (Osmani and O'Reilly, 2009). For the moment, this only addresses the operational energy use and carbon dioxide emissions related to this issue. ...
For the European Union (EU), the energy demand of the building sector is evaluated at 40% of final energy consumption. Within this, the residential sector accounts for 63% of total energy consumption. These values justify the sustained effort for increasing building energy performance and to obtain efficient building materials, designs and solutions. However, the exclusive use of conservative construction products creates further problems as they require a considerable amount of energy for production and end-of-life management, in a context where EU priority issues are an efficient post-use of building materials, preferably in a circular economy context, and moving towards "zero carbon" buildings, a concept that soon will integrate the embedded energy and CO2 emissions. Therefore, it is essential to find new ways to reduce both the embedded CO2 in building materials, as well as CO2 associated with operational energy and to facilitate the post-use integration in economy. This paper presents a sustainable solution that meets these requirements, by integrating natural resources and agriculture by-products, with minimum embedded energy, in a novel design suitable for industrialization. The model is assessed from the point of view of the building energy demand and compared with a conventional unit using the same architecture.
... Even if global warming potential (GWP) of a typical external wall compared to other building elements are relatively low, e.g. 3% of the total greenhouse gas emissions of the building calculated by Sodagar et al. [2], it is nevertheless important to reduce embodied environmental impacts in all building components to achieve nearly zero emission buildings. ...
Straw bale is a low embodied energy and technically acceptable thermal insulation material. As per today, there is a lack of standardized technical data on utilizing straw bale in building construction, while the existing research studies rather focus on limited specific experimental or computational scenarios without summarizing in an organized way the behaviour of straw bale construction under different climate conditions and assembly configurations. This comparative study presents systematically the hygrothermal and energy performance of straw bale buildings with different exterior cladding and finishing mortar or sheathing board, exposed in various representative climates. The findings provide an insight into the optimal selection of materials and furthermore highlight the importance of climate adaptation of straw bale wall constructions. Overall, straw bale buildings show robust hygrothermal performance, when properly designed, and achieve very low energy use at a minimum of embodied emissions.
... Compared with conventional building thermal insulation materials, biomass thermal insulation materials consume less energy and are more environmentally friendly (Liuzzi et al., 2017). The studies conducted by Mattila et al. (2012) and Sodagar et al. (2011) confirmed that straw bales can effectively reduce the carbon emissions of buildings when considering the carbon sink. Gonzalez (2014) andD'alessandro et al, (2017) accurately calculated the ECE and carbon sink of the straw bale wall, confirming the carbon reduction of straw bale. ...
To cope with the problem of global warming and achieve sustainable development of society, controlling carbon emissions becomes more and more important. The completed area of rural houses in China is growing fast, and emitting large greenhouse gases in construction. In this study, the hybrid life cycle assessment (Hybrid-LCA) is used to calculate the embodied carbon emissions (ECE) of straw bale rural houses. The results show that the carbon emissions of building materials accounts for 97% in the materialization stage, while the material transportation and construction stages contribute to only about 3%. The wood-structure and light-steel structure are worth recommend low carbon straw bale rural houses, the net carbon emission can be reduced by 96.75% and 76.92% compared with the reference rural houses. The structural type of the rural houses will influence the carbon emission of the full materialization stage. By replacing high carbon materials with low carbon materials such as straw bale in ordinary rural houses, the ECE of rural houses can be reduced by 39.54%. The findings of this study will shed important light on the low carbon construction of rural houses in the future.
... Engineered timber can be employed in low-to mid-rise structures (up to 30 m, 6 floors; see Tollefson [110]). A less popular, yet promising type of material is agricultural waste products, which could substitute concrete and other traditional materials, and in doing so, diminish the carbon emissions by storing carbon in its structure [68,111]. Using timber instead of concrete, whenever feasible, allows a decrease in buildings' environmental impact up to 43% in terms of embodied energy and 68% in terms of embodied carbon. ...
Life cycle assessment is a tool to quantify the environmental impact of products and has been widely studied in the building context. This is an important context given the building sector's substantial embodied energy and carbon. Against this backdrop, this study has two main objectives. The first objective is to create a benchmark the environmental impact of buildings. The second objective is to develop a procedural guideline that assists practitioners in decreasing the environmental impact of buildings. To achieve these objectives, a systematic review of the relevant literature was conducted to categorize and summarize relevant studies. A meta-analysis followed to synthesize the life cycle assessment results that emerged from the collected articles. The articles were categorized into two main groups: articles on construction materials and articles on entire buildings. Eight construction materials (i.e., concrete, reinforcement bars, structural steel, timber, tiles, insulation, and plaster) and three building types (i.e., concrete, timber, and steel) were identified, and related embodied energy and carbon were extracted. Subsequently, the data were analyzed through descriptive and inferential statistics. Findings from the meta-analysis informed a regression model, which in turn informed a procedural guideline for practitioners who seek to reduce buildings' environmental impact. Further, the findings of this paper shed light on previously equivocal results concerning the impact of construction materials and buildings, but also support previous findings for structural materials, showing, for example, that the use of timber structures results in substantial savings over concrete structures in terms of both embodied energy (43%) and carbon (68%).
... The most typical modern construction uses include straw bales that are attached between loadbearing timber studs or straw-clay mix that can be cast into different structures. The carbon storage potential of straw bale construction has been studied and compared to that of biochar (Mattila et al. 2012) to typically used bricks or blocks (Gonzalez 2014), and to other typical building materials (Sodagar et al. 2010). Although straw in construction is to a certain extent vernacular, it is widely used, thus allowing it be ranked at TRL 9. ...
In order to reach carbon neutrality, GHG emissions from all sectors of society need to be strongly reduced. This especially applies to the construction sector. For those emissions that remain hard to reduce, removals or compensations are required. Such approaches can also be found within the built environment, but have not yet been systematically utilized. This paper presents a review of possible carbon storage technologies based on literature and professional experience. The existing technologies for storing carbon can be divided into 13 approaches. Some are already in use, many possess the potential to be scaled up, while some presently seem to only be theoretical. We propose typologies for different approaches, estimate their net carbon storage impact and maturity, and suggest a ranking based on their applicability, impact, and maturity. Our findings suggest that there is an underutilized potential for systematically accumulating atmospheric carbon in the built environment.
... The CO 2 is converted into organic matter and stored in the bio-based building fabric. This increases the quantity of CO 2 sequestered from the environment [44]. These materials have a lower environmental impact on life cycle assessments (LCAs) [45]. ...
Due to the cold winters in northeast China, the energy consumption of the rural residential buildings is much higher in this region than in other regions. In this study, the energy sustainability of bio-based wall construction is examined through applications in rural residential buildings. Comparisons of the energy sustainability of the bio-based wall constructions and the conventional wall constructions are evaluated using IESVE-2019 computational simulation. The results show notable reductions in heating energy requirements and coal use, which is the major heating source for rural residential buildings in China. The results show that reductions of 45.82–204.07 kWh/m²/year in heating energy requirements and more than 40% in coal use are possible through application of bio-based wall constructions. The application of bio-based wall construction will result in lower seasonal air pollution and coal use through straw burning in northeast China.
... The prospects of reinventing building material such as stone, earth, and straw bale could propel environmental responsiveness, resilience, and sustainability. Straw, earth, and stone as materials with long history proven to exhibit great sustainability potentials (Opaluwa, Obi, & Osasona, 2012;Sodagar, Rai, Jones, Wihan, & Fieldson, 2011). Hence, deploying appropriate technology on these materials could assist in achieving sustainability goals. ...
Culture and tradition are essential components of the traditional architecture. However, in the era of globalization and modernization, traditional architecture is fast disappearing in most part of Africa due to neglect and lack of understanding of its importance. A reconsideration becomes necessary as traditional architecture can be a source of inspiration even in contemporary times. Through a systematic literature review, this article takes a critical look at how culture affects architecture in Africa with Nigeria as a case study. It explores various traditional architectural accomplishments across Africa revealing the disappearance of cultural identity and the weak connection between traditional and contemporary architecture. It then concludes with strategies toward survival and revival of indigenous African architecture with clear direction on architects' key roles in persevering the Africans endangered culture.
... Life cycle assessment of hemp cultivation and use of hemp-based insulating materials in buildings was covered in [143] considering the impact of production practices on environment [144]. Results report values of production energy requirements of 11 400 MJ/ha (compared to 18 100MJ/ha for wheat and 23 000MJ//ha for maize).The earliest UK environmental analysis / LCA of bio -based constructions concerned straw bales and carbon reduction potential of 61.0% was reported for a 60-years life building [145]; confirming the de-carbonation or 'carbon-sink' potential of bio-based buildings. Life cycle assessment of sprayed hemp concrete wall (considering wall thickness and wall coating) was performed and results reported in [2]. ...
Bio-based building materials are composites of vegetal particles embedded in an organic or mineral matrix. Their multi-scale porous structure confers to them interesting thermal, hygroscopic and acoustic properties. These performance properties have spurred research on these materials as alternative building materials with low embodied energy. This review contains a comprehensive critical analysis of mechanical, thermal, and acoustic properties of bio-based building materials with a particular focus on the interactions of various constituents and manufacturing parameters. Alkali-activated binders are reviewed for their potential use in high strength bio-based composites. A detailed physico-chemical characterisation of the aggregates and compatibility analysis allow a comprehensive understanding of fundamental phenomena affecting mechanical, thermal, and acoustic properties of bio-based building materials. A wide range of biomass materials is available for building composites, and hemp shives remain the most prevalent bio-aggregate. In the context of England, the farming of industrial hemp remains limited, due in part to the long, costly licencing process and the abandonment of processing subsidy as part of the EU common agricultural policy in 2013. On the other hand, Miscanthus (elephant grass) is a perennial, low-energy, and well-established crop in the England which is gaining interest from farmers in the South West region. Its development aligns with actual agricultural, land management and environmental policies with potential to fuel innovative industrial applications. This review performs a critical assessment of the performance of bio-based materials in an attempt to identify potential frameworks and opportunities to develop building insulating materials from miscanthus.
... Existing research include several individual case studies in which design options are tested, although, in general, only one design parameter is evaluated at a time, e.g. using bio-based materials (Salazar & Meil, 2009;Sodagar, Rai, Jones, Wihan, & Fieldson, 2011), design for disassembly (Eberhardt, Birgisdóttir, & Birkved, 2018;Tingley & Davison, 2012) or design for low operational energy use (Kristjansdottir, Heeren, Andresen, & Brattebø, 2017). However, these single-case examples apply different methodological approaches in the LCA. ...
This study presents the environmental life cycle assessment of four low carbon design strategies applied in Danish, architectural practice. The subject of analysis is a set of five buildings erected within the same constrictions in terms of floor area, energy performance and construction costs. The tested design strategies were: use of recycled materials, design for extended durability of components, adaptable design, and design for reduction of operational energy demand. The results of the five buildings are compared with a reference building (i.e. a typical, Danish single-family dwelling). Results show that the recycling/upcycling strategy is the most effective in reducing the embodied carbon. The use of structural wood in the same design furthermore points to the use of wood as a viable low-carbon strategy. In combination, these two strategies result in an approximate 40% saving of life cycle embodied carbon compared to the reference. Using durable materials yields up to 30% lower embodied carbon compared to the reference, whereas a design for adaptability results in 17% lower embodied carbon. However, these results are sensitive to the scenarios made for the service lives of materials and the implemented disassembly solutions. In a life cycle carbon perspective, the emissions from energy use prove to be of importance, although depending on the modelling approaches of the energy mix. With the shrinking, global carbon budgets in mind, there is justified reason to holistically optimize the design of new buildings by integrating various design aspects addressing the whole life cycle of the building.
... Over the last ten years, many advantages of this sustainable material have been recognized. First, straw bales act as a carbon sink, and they have significantly lower embodied energy and carbon content than conventional materials [10]. As an example, González [11] estimated that the energy embedded in straw bales needed to cover 1 m 2 of wall is about 28 MJ, meaning that they are less impactful than the same area covered by fired bricks (488 MJ/m 2 ) or concrete blocks (169 MJ/m 2 ). ...
This paper investigates the performance of timber-framed walls insulated with straw bales, and compares them with similar walls containing expanded polystyrene (EPS) instead of straw bales. First, thermal conductivity, initial water content, and density of the straw bales were experimentally measured in a laboratory set-up, and the dependence of the thermal conductivity of the dry material on temperature was described. Then, the two insulation solutions were compared by looking at their steady and periodic thermal transmittance, decrement factor, phase shift, internal areal heat capacity and surface mass. Finally, the acoustic performance of both wall typologies was analyzed by means of in situ measurements in two-story buildings built in Southern Italy. The weighted apparent sound reduction index for the partition wall between two houses and the weighted standardized level difference for the façades were assessed based on ISO Standard 16283. The results indicate that the dry straw bales have an average thermal conductivity of k = 0.0573 W/(m·K), and their density is around 80 kg/m³. In addition, straw bale walls have good steady thermal performance, but they still lack sufficient thermal inertia, as witnessed by the low phase shift and the high periodic thermal transmittance. Finally, according to the on-site measurements, the results underline that the acoustic performance of the straw bale walls is far better than the walls adopting traditional EPS insulation. Overall, the straw bales investigated are a promising natural and sustainable solution for thermal and sound insulation of buildings.
... The prospects of reinventing building material such as stone, earth, and straw bale could propel environmental responsiveness, resilience, and sustainability. Straw, earth, and stone as materials with long history proven to exhibit great sustainability potentials (Opaluwa, Obi, & Osasona, 2012;Sodagar, Rai, Jones, Wihan, & Fieldson, 2011). Hence, deploying appropriate technology on these materials could assist in achieving sustainability goals. ...
Culture and tradition are essential components of the traditional architecture. However, in the era of globalization and modernization, traditional architecture is fast disappearing in most part of Africa due to neglect and lack of understanding of its importance. A reconsideration becomes necessary as traditional architecture can be a source of inspiration even in contemporary times. Through a systematic literature review, this article takes a critical look at how culture affects architecture in Africa with Nigeria as a case study. It explores various traditional architectural accomplishments across Africa revealing the disappearance of cultural identity and the weak connection between traditional and contemporary architecture. It then concludes with strategies toward survival and revival of indigenous African architecture with clear direction on architects’ key roles in persevering the Africans endangered culture.
In the present study, the prepared bio-composite materials based on flax fibers containing caffeine or nano-copper (Cu) or corundum (Al 2 O 3 ) as a potential biocidal substance were prepared and tested on their toxicity. Two viability tests were performed. Firstly, the screening test based on colouring by Methyl-blue was applied on yeast cells of strain Saccharomyces cerevisae . The number of cells density was observed under microscope and Methyl-blue was then added. Part of the cells coloured in blue and it indicated their death. For this reason, MTT viability assay was performed. The method is based on production of blue product formazan by yeasts after their metabolization of added initial substrate, 3-[4,5-dimethylthiazol-2-yl]-2,5-difenyltetrazolium bromide. The intensity of blue-coloured formazan was measured spectrophotometrically at 485 nm. The results indicated that the inhibition of yeasts was increased in the following rate: cu-samples (14-16 %) < flax sample without biocidal substances (21%) = pure flax (23 %) < caffeine-samples (up to 29 %) < corundum-samples (up to 35 %).
In recent years, scientists have found that the consequences of human-induced climate change can endanger the whole planet and cause destruction of many ecosystems. One of the primary and comprehensive global actions to prevent destruction and preserve healthy ecosystems was the 17 Sustainable Development Goals (SDGs) that were adopted by all United Nations members in 2015. Humans need to change their behavior, and industries must move toward SDGs if we are looking ahead to a brighter future. The building construction industry uses huge quantities of raw materials and is involved in high energy consumption. This industry has been known as one of the most polluting sectors that have caused enormous adverse environmental impacts. Immediate action is necessary to reduce these negative impacts. Building materials are mainly responsible for most environmental impacts, and finding eco-friendly alternatives is crucial. Bio-based materials have shown great potential to be used in buildings. Different types of bio-based materials have been tested in buildings, and the results were promising. These materials improve both the environmental and economic aspects of building construction. In this chapter, most common bio-based building materials are introduced, and their contribution to SDGs is indicated.
Fascinating share from specific natural additives are used during the formation of constructions and paths. From them, hazardous gases are departing. These gases are crucial to the variance in the earth's atmosphere. Cannabis Sativa, gokshura are natural resources(carbon negative material) from the medieval period are using essentially like a cheap environmental bearing substance against numerous composite commodities. Within structures, this is frequently practiced, including a lime filler cover inside drywall structures. Some precise data ready to judge the atmosphere behavior of here kind of structure in India, UK. Here analysis strives to recognize the methods and supplies associated with the development of cannabis sativa, chrysopogen zizanoides walls blended with lime and strengthening their maturity classification impact upon climate alteration. This research obeys methods including guidelines regarding worldwide (ISO14040) and UK (PAS2050) measures. We will execute cannabis Sativa -lime drywall frame is 1m2 in range, 315 millimeters including wood framing brace internally. The investigated parts of hempcrete consolidate characteristics of hemp appropriate to development, binder qualities, mechanical properties, sturdiness, and melting properties, natural qualifications, fabricating cycles, and current applications. A few exploration gaps concerning the hydraulic nature of the binder, strength, and sturdiness, and burning obstruction of hempcrete were verified. This was additionally settled that hempcrete has remarkably moderate embodied carbon, some other gases and encapsulated power, addressing it absolute for natural additive structure pertinence. The conclusion closes with a conversation illustrating the demand and aiming for future examination on enhancing the amount of co2 other greenhouse gaseous sequestration from natural additives while blending with lime and also to increase compressive strength of lime.
Cities are hotspots of anthropogenic activity and consumption. Thus, the consumption-based carbon footprints of their residents are pronounced. However, the beneficial climate impacts attributable to individual residents, such as carbon sequestration and storage (CSS) provided by residential green spaces and housing, have received less attention in the scientific literature. This review article presents an overview of the current research on the urban residential environment's CSS potential and argues for its inclusion in the so-called carbon handprint potential of individual consumers. The focus of existing research is on developed countries, and in empirical studies the absence of compiling literature presents a clear research gap. Most current potential is estimated to lie within the carbon pools of residential vegetation, soils and wooden construction, with biochar and other biogenic construction materials presenting key future development pathways. The underlying background variables guiding the formation of a residential carbon pool were identified as extremely complex and interconnected, broadly classified into spatial, temporal and socioeconomic factor categories. Our findings suggest that there is significant potential for growth in the residential CSS capacity, but substantial efforts from the scientific community, urban planners and policy-makers, and individual residents themselves are needed to realise this.
Executive summary The development and operation of the built environment could play a key role in the mitigation efforts. However, the transition towards more sustainable settlements requires massive use of materials and energy in new energy efficient buildings, and supporting infrastructures. Traditionally the embodied emissions from materials have not been considered of high importance, but since the construction of energy efficient buildings and modern infrastructure causes more GHG emissions than conventional ones, the embodied emissions are becoming more crucial. However, evaluating the environmental burden of construction materials has proved problematic and despite the significant research around the world, the reliability of estimates is still highly questionable. Also, there is growing consensus among organizations committed to environmental performance targets that appropriate strategies and actions are needed to make construction activities more sustainable. The pace of actions towards sustainable application depends on decisions taken by a number of stakeholders in the construction process: owners, managers, designers, firms, etc. Careful selection of sustainable building materials has been identified as the easiest way for designers to begin incorporating sustainable principles in building projects. Yet, the selection of building materials is considered as a multi-criteria decision problem. Ideally, sustainability assessment would integrate social, technical, environmental and economic considerations at every stage in decision-making. The three objectives of the EmBED project were to: 1. improve the current assessment practices in the construction sector 2. provide reliable estimates for the embodied environmental impacts caused by the development of the built environment in Iceland 3. develop an assessment framework for construction materials based on Multi-criteria decision analysis approach We employ life cycle assessment (LCA), the most widely accepted and used assessment method in the construction sector for an integrated assessment of environmental impacts from cradle to grave (Heinonen et al., 2016; Suh et al., 2004a) for five case studies. LCA is a method to assess various aspects associated with development of a product and its potential impact throughout a product's life from raw material acquisition, processing, manufacturing, use and its disposal. Besides, based on Multi-criteria decision analysis approach, an assessment framework with multiple criteria for the selection of sustainable material for construction projects in Iceland has been developed. The purpose of case study 1 was to measure the environmental impacts from construction materials used in the Vaettaskóli-Engi school building, focusing on the influence of the source of materials (locally produced vs. imported). The system boundary covers four pre-use phase modules of A1-A4 as designated in the standard EN 15804. Total impacts per square meter of gross floor area from the materials employed in the building were estimated to be 255 kgCO2 eq/sqm, 1.36E-06 kg CFC 11 eq/sqm, 3.23E-05 CTUh/sqm, 0.88 Mole of H+ eq/sqm and 2.28 Mole of N eq/sqm. In addition, as expected, it was concluded that producing the cement in Iceland caused less environmental impacts in all five impact categories compared to the case in which the cement is imported from Germany. If the concrete was imported, total environmental impacts of the school would rise by 5.7% and 2.5% in terms of GWP and HT, while there would be no significant differences in terms of ODP impact. Also, a considerable rise (more than 50%) in terms of overall AP and EP would be expected. The additional impacts are all due to the transportation of cement to Iceland for concrete production. The study of two actual buildings (cases 2-3) has demonstrated how the estimates from the two most widely utilized LCA tools are incompatible for all studied impact categories other than Climate Change. The main conclusion is that without further development of the assessment methods and the databases, the results should not be utilized to support decision-making, except for Climate Change results. Similarly, it is not encouraged to use endpoint indicators or single-score indicators at all if the different impacts cannot be localized/contextualized according to the actual production and delivery chains of different components. Even then, it should be carefully tested if the outcome is similar for different buildings and when the processes are adjusted to the actual production places and technologies, transport distances, etc. Humanitarian refugee shelters (like case study 4), are environmental burdens because of their energy requirements and GHG emissions. Over the last decade, studies on LCA for post-disaster housing have grown rapidly. This trend is expected to continue in the near future because of the mounting demand for temporary housing. This study has shown a proof of concept example for a low-impact refugee house prototype using straw, reeds, clay, lime, and wood as the principal raw construction materials. Using natural materials, especially plant-based fibres, as the main construction materials, proved to achieve a minus carbon outcome over the life cycle of the building. The GWP of the shelter house without and with sequestration was found to be 254.7 kg CO2 eq/m 2 and-226.2 kg CO2 eq/m 2 , respectively. With the use of plant-based fibres in the construction of the building, passive and eco-cycle systems for the building's operation resulted in a negative GWP impact. Based on the results of the uncertainty importance analysis, the overall GWP impact without and with sequestration potential varied the most due to the variability of the GWP impact of wood fibre insulation. There is great potential in working with such eco-and low-impact design and construction methods for both temporary and permanent housing solutions to achieve a minus carbon footprint. The fifth study was set to assess a rough estimate for the GHG emissions from built environment development in Iceland. Typically building and infrastructure system assessments are done over the lifetime of the assessment object and to one object at a time, which gives little information about the overall annual GHG load from all building and infrastructure construction activities. This study thus provides one case example, which can in the future be used as a benchmark and complemented with other studies. It was found that the GHGs from built environment development should be taken into account when designing GHG mitigation strategies in the context of the built environment, such as building energy efficiency regulations and infrastructure development projects to facilitate low-carbon transport. Otherwise, it may happen that the "carbon investment" in the development phase is never paid back or the payback is longer than would be acceptable. After conducting stakeholder analysis, key stakeholders have been identified and classified into four groups. Besides, the decision criteria for the selection of sustainable material for construction have been documented. The questionnaire was designed to capture the preferences of different stakeholders on decision criteria and indicator and the pilot run shows the applicability and effectiveness of the questionnaire for this purpose.
Günümüzde yapı sektöründe çevresel etkiyi önceleyen bilimsel araştırmalar, çelik ve betonarme gibi sıklıkla kullanılan yapı malzemelerinden ziyade karbon salınımı düşük, gömülü enerjisi az olan yapı malzemelerine yönelmektedir. Yüksek karbon tutma potansiyeline sahip ve tarımsal üretimden arta kalan bitkisel malzemeler, düşük karbon ayak izi ve sürdürülebilir özellikli bir malzeme olması nedeniyle yapı üretiminde kullanımı giderek artmaktadır. Bu malzemelerden biri, yakılarak yok edilmelerini önleyen herhangi bir kullanım sayesinde CO2 salınımının azaltılmasına önemli katkı sağlayan, antik zamanlardan beri kullanımı bilinen samandır. Yapı üretiminde yoğun olarak kullanılan diğer yapı malzemelerinin (beton, çelik, tuğla vb.) aksine saman, insan sağlığına zararlı bileşenleri içermemektedir. Doğal yöntemler kullanılarak gerçekleştirilen hasat ve balyalama işlemleri sırasında herhangi bir endüstriyel süreç ve kimyasal madde kullanılmamaktadır. Dolayısıyla saman herhangi bir toksin açığa çıkarmaz ve yapı duvarlarını oluşturan doğal bir malzeme olarak kalır. Bilinen geleneksel yapı malzemeleriyle kullanımının yanı sıra saman, balya halinde doğrudan ya da mühendislik ürünü ahşap malzeme sistemle entegre prefabrik panel (PSB-prefabricated straw bale) biçiminde de yapı üretiminde kullanılmaktadır. Bu çalışmada, düşük çevresel etkilere sahip, enerji verimliliği yüksek binalar elde etmek için en verimli yapım yöntemlerinden biri olarak kabul edilen prefabrik saman balya panel (PSB) eleman kullanımının çevresel etkileri ve yapı üretim süreci araştırılmıştır. Ayrıca prefabrik saman panelin oluşturulmasında kullanılan farklı bileşenlerin (bağlantı sistemleri, bitirme katmanları vb.) toplam U (W/m²K) değerine olan etkisi irdelenmeye çalışılmıştır.
The increasing interest in bio-based construction materials has resulted in the emergence of the concept of “buildings as a carbon sink”. Quantifying and comparing the effects of carbon sequestration and storage in buildings from a life cycle perspective involves the evaluation of flows and processes taking place at different timescales and across ecological, technological, and economic domains. This scoping review sheds light on the heterogeneous body of approaches and results from relevant scientific literature of the past decade: 180 articles were reviewed following a systematic search and relevance-checking process. Contributions are evaluated based on the scale of interest (material, building, building stock), the sequestration mechanism (photosynthesis, carbonation) and the accounting methodology adopted to quantify global warming. The majority of works taking a life cycle perspective adopt static methods, with only a few accounting for dynamic effects over time, although more recent studies do tend to recognise the need for dynamic life cycle assessment. A characterisation of current and future carbon storage in the global building stock is still needed, and substantial work remains to be done to validate the theory of buildings as a carbon sink to mitigate the effects of climate change. Reports on carbon stored in durable construction products and buildings mostly find cumulative effects that are less than emissions from fossil fuel use in a single year (ranging from negligible to 175%). Furthermore, net gains in storage in the built environment can be offset by net losses in forest carbon, and the benefits of substitution with wood are sometimes overstated. Further adoption of bio-based construction materials can – at best – only make a substantial contribution to climate change mitigation in the context of rapid global progress in decarbonisation.
Globally, more and more buildings are constructed as the basis of green methodology. Green building methodology includes the reduction of energy from the conception through the operation phases. Importantly, the practice of green building is gradually becoming more regulatory compliance rather than optional. Subsequently, this paper will carefully review the adaptability of materials in green buildings. In supporting such aim, this paper will also reviewed five Australian case studies. For these building, as a part of adaptability of green materials, recycled concrete, metal and timber were utilized. It was found that most benefits of adaptability of materials for these buildings were significantly improved with the integration with sustainable design. Such alignment is the key for effective material selection and usage in green buildings. The use of green materials alone may be not be enough to considerably reduce the energy usage. Holistically, the green design together with recycled materials need to be combined to deliver efficient green buildings.
The “upfront” embodied carbon (EC) of building materials includes the accumulated greenhouse gas (GHG) emissions resulting from harvesting, manufacturing and transportation processes, and is becoming more widely recognized as a major source of global GHGs. The aim of this study is to demonstrate the potential for buildings to go beyond reduced or zero GHG emissions and to become– at least temporarily – a negative emissions technology, namely places of net storage of carbon. The study examines the EC for two samples of low-rise residential buildings that are representative of the North American wood-framed typology: a single-unit raised bungalow of 185m2 and an eight-unit, four-story of 935 m2. Data from Environmental Product Declarations (EPDs) for a wide variety of materials that could feasibly be used to construct the sample buildings are used to calculate the total EC for four different material assemblies in each building type: High EC, Typical EC, Best Conventional EC and Best EC. Results demonstrate the upfront embodied carbon can vary widely, ranging from a worst-case scenario of 415 kgCO2e/m2 of net emissions to a best case of 170 kgCO2e/m2 of net carbon storage by using biogenic (plant-based) materials. In addition, an energy modeling analysis of the buildings was conducted for the Toronto, Ontario climate to compare the EC with the operational carbon (OC) emissions. The results show that achievable reductions in EC could provide more than four times the overall GHG reductions than energy efficiency improvements to reduce OC between 2020 and 2050. The building model with both the lowest EC and OC is shown to have net carbon storage for several centuries. At the current scale of US residential construction, annual carbon storage in residential buildings as modeled could reach 30,000,000 tonnes, the equivalent of 10 coal-fired power plants. The immediate impact of large-scale GHG reductions from the use of carbon-storing materials is demonstrated to be worthy of consideration for the building industry and related policy makers.
Wheat straw, in the form of compacted bales, is increasingly used as thermal insulation in the external walls of buildings. Common practice is to use a render finish, applied directly to surface of the straw bales, to protect them from decay, and enhance structural performance and fire resistance. Coatings are typically made of water vapour permeable materials, such as lime or earth-based renders. Such coatings should allow water vapour to diffuse through, minimising the risk of liquid moisture build up within the thickness of the wall, reducing likelihood of decay. However, to date there has been very limited scientific study of this behaviour in rendered straw bale walls. The aim of the work presented in this paper was to develop understanding of the hygrothermal performance of lime rendered wheat straw bales. A test panel was subjected to varying environmental conditions, including a thermal shock, dynamic freeze–thaw exposure and hot humid conditions. Key scientific contributions of this work include data on the dynamic and steady-state hygrothermal characteristics wheat straw bale walls, combined with the application of heat and moisture modelling. This work will further support uptake of straw bale construction by designers and their wider use in energy-efficient construction projects.
The rising profile of carbon footprinting in building lifecycle has caught the attention of many in the construction industry and academic circles. There is an increasing awareness of the effectiveness of an holistic approach by calculating the entire impact of the building by considering all stages of whole life carbon emissions including the initial, annually repeating and end of life impacts as this gives a better representation of the scale of the impact compared with focusing on savings achieved by adopting a specific elemental choice.
It is now widely realized that we are living on a planet with finite resources and that we should make every effort to reduce our ecological footprint. Within the construction industry, it is now accepted that tackling environmental sustainability alone is not sufficient and that we have to adopt a holistic approach by addressing the other two aspects of sustainability namely social and environmental. To reduce its huge impact, accounting for almost half of the global greenhouse gases and consumption of the materials entering the global market, the industry has succeeded in developing new and innovative solutions. These include the reintroduction of traditional construction techniques, refurbishment and conversion against new built, renewables and similar initiatives.
This paper investigates savings in the carbon emissions of refurbishing buildings compared against a new build scenario. Whole life emissions calculations have been carried out to analyse the total environmental impact including embodied and operational stages of building life cycle. The paper also highlights the results of the survey carried out to analyse the building in-use dimensions for environmental quality of the newly refurbished office building.
A companion paper presented the life cycle inventory (LCI) calculation model for buildings as a whole, developed within a global methodology to optimise low energy buildings simultaneously for energy, environmental impact and costs without neglecting the boundary conditions for thermal comfort and indoor air quality. This paper presents the results of a contribution analysis of the life cycle inventory of four typical Belgian residential buildings. The analysis shows the relative small importance of the embodied energy of a building compared to the energy consumption during the usage phase. This conclusion is even more valid when comparing the embodied energy of energy saving measures with the energy savings they realise. In most studied cases, the extra embodied energy for energy saving measures is gained back by the savings in less than 2 years. Only extremely low energy buildings might have a total embodied energy higher than the energy use of the utilisation phase. However, the sum of both remains small and the energy savings realised with these dwellings are large, compared to the energy consumption of average dwellings.
The Australian Department of Commerce builds many secondary schools in New South Wales every year, and the impact of energy consumption for such a type of construction has rarely been done before in Australia. Although there is a particular responsibility to ensure that public-owned projects contribute to the future well-being of the natural environment, environmental performance and energy efficiency of public projects are not well studied. In order that more informed design and planning decisions can be made about the future construction of school projects, this research paper uses life cycle energy analysis to study the total energy consumption of 20 public secondary school projects in New South Wales. The results will serve as a model for a more comprehensive analysis of energy consumption in establishing environmental performance criteria for the design and construction of future school projects in New South Wales.
The article provides a life cycle assessment (LCA) of a 3-bed room semi detached house in Scotland. Detailed LCA of five main construction materials i.e. wood, aluminium, glass, concrete and ceramic tiles have been provided to determine their respective embodied energy and associated environmental impacts. Embodied energy of various construction materials involved has been estimated to be equal to 227.4 GJ. It is found that concrete, timber and ceramic tiles are the three major energy expensive materials involved. It as been calculated that concrete alone consumes 65% of the total embodied energy of the home while its share of environmental impacts is even more crucial.
Wheat straw (an agricultural by-product) was pulped by an alkaline anthraquinone (AQ) process. Then the straw pulp was treated by high-power ultrasound under different noble-gas (argon, krypton, xenon) combinations. The pulps' degree of beating and acid-insoluble lignin content were measured. Handsheets were made from sonicated and control pulps and tested for paper tensile strength. In this study we explore which noble-gas combination with ultrasound may be more useable to reduce the lignin content and enhance fibrillation. We also describe the most effective ultrasound-assisted, modified alkaline pulping process. Overall, we found that in two steps ultrasonification decreased the residual lignin contents more then 75 %, the pulp fibrillation increased from 12 to 70 °SR within 20 min. of ultrasound irradiation, and the tensile index of the handsheets increased by 65%. For sustainable paper production, it is required to develop alternative paper resources. Paper made from alternate fiber resources with efficient technology will improve our living standards without sacrificing the environment, our habitat. High frequency ultrasound-based pulp processing offers significant improvements, and it reduces energy and chemical consump-tions for pulp and paper production.
A literature survey on buildings' life cycle energy use was performed, resulting in a total of 60 cases from nine countries. The cases included both residential and non-residential units. Despite climate and other background differences, the study revealed a linear relation between operating and total energy valid through all the cases. Case studies on buildings built according to different design criteria, and at parity of all other conditions, showed that design of low-energy buildings induces both a net benefit in total life cycle energy demand and an increase in the embodied energy. A solar house proved to be more energy efficient than an equivalent house built with commitment to use "green" materials. Also, the same solar house decreased life cycle energy demand by a factor of two with respect to an equivalent conventional version, when operating energy was expressed as end-use energy and the lifetime assumed to be 50 years. A passive house proved to be more energy efficient than an equivalent self-sufficient solar house. Also, the same passive house decreased life cycle energy demand by a factor of three - expected to rise to four in a new version - with respect to an equivalent conventional version, when operating energy was expressed as primary energy and the lifetime assumed to be 80 years.
In this study the life cycle primary energy use and carbon dioxide (CO2) emission of an eight-storey wood-framed apartment building are analyzed. All life cycle phases are included, including acquisition and processing of materials, on-site construction, building operation, demolition and materials disposal. The calculated primary energy use includes the entire energy system chains, and carbon flows are tracked including fossil fuel emissions, process emissions, carbon stocks in building materials, and avoided fossil emissions due to biofuel substitution. The results show that building operation uses the largest share of life cycle energy use, becoming increasingly dominant as the life span of the building increases. The type of heating system strongly influences the primary energy use and CO2 emission; a biomass-based system with cogeneration of district heat and electricity achieves low primary energy use and very low CO2 emissions. Using biomass residues from the wood products chain to substitute for fossil fuels significantly reduces net CO2 emission. Excluding household tap water and electricity, a negative life cycle net CO2 emission can be achieved due to the wood-based construction materials and biomass-based energy supply system. This study shows the importance of using a life cycle perspective when evaluating primary energy and climatic impacts of buildings.
A comprehensive case study life cycle assessment (LCA) was conducted of a 7300 m2, six-story building with a projected 75 year life span, located on the University of Michigan campus. The bottom three floors and basement are used as classrooms and open-plan offices; the top three floors are used as hotel rooms. An inventory of all installed materials and material replacements was conducted covering the building structure, envelope, interior structure and finishes, as well as the utility and sanitary systems. Computer modeling was used to determine primary energy consumption for heating, cooling, ventilation, lighting, hot water and sanitary water consumption. Demolition and other end-of-life burdens were also inventoried.The primary energy intensity over the building’s life cycle is estimated to be 2.3×106 GJ, or 316 GJ/m2. Production of building materials, their transportation to the site as well as the construction of the building accounts for 2.2% of life cycle primary energy consumption. HVAC and electricity account for 94.4% of life cycle primary energy consumption. Water services account for 3.3% of life cycle primary energy consumption, with water heating being the major factor, due to the presence of hotel rooms in this building. Building demolition and transportation of waste, accounts for only 0.2% of life cycle primary energy consumption.All impact categories measured (global warming potential, ozone depletion potential, acidification potential, nutrification potential and solid waste generation) correlate closely with primary energy demand.The challenges in developing a life cycle model of a complex dynamic system with a long service life are explored and the implications for future designs are discussed.
The use of straw bales for the construction of buildings in the UK has to date generally been limited to the self-build fringe sector. In order to bring this form of construction into the mainstream sector, to benefit from its inherent low carbon and high insulation characteristics, it is necessary to guarantee the long-term durability of the straw. Maintaining low moisture levels is critical to the long-term resistance of straw to biological decomposition. This paper presents results from a study on moisture monitoring in straw bale construction, and includes the development of an empirical equation which relates straw moisture content to surrounding microclimate relative humidity and temperature. This knowledge allows continuous non-invasive condition monitoring of the straw in on-going research work and potentially as part of future managed maintenance of straw bale buildings.
The space heating demand of residential buildings can be decreased by improved insulation, reduced air leakage and by heat recovery from ventilation air. However, these measures result in an increased use of materials. As the energy for building operation decreases, the relative importance of the energy used in the production phase increases and influences optimization aimed at minimizing the life cycle energy use. The life cycle primary energy use of buildings also depends on the energy supply systems. In this work we analyse primary energy use and CO2 emission for the production and operation of conventional and low-energy residential buildings. Different types of energy supply systems are included in the analysis. We show that for a conventional and a low-energy building the primary energy use for production can be up to 45% and 60%, respectively, of the total, depending on the energy supply system, and with larger variations for conventional buildings. The primary energy used and the CO2 emission resulting from production are lower for wood-framed constructions than for concrete-framed constructions. The primary energy use and the CO2 emission depend strongly on the energy supply, for both conventional and low-energy buildings. For example, a single-family house from the 1970s heated with biomass-based district heating with cogeneration has 70% lower operational primary energy use than if heated with fuel-based electricity. The specific primary energy use with district heating was 40% lower than that of an electrically heated passive row house.
The field of building environmental assessment tools has become a popular research area over the past decade. However, how the service life of a building affects the results of the environmental assessment of a building has not been emphasised previously. The aim of this study is to analyse how different structural solutions and building materials affect the results of the environmental assessment of a whole building over the building's life cycle. Furthermore, how the length of the building's service life affects the results is analysed. The environmental assessments of 78 single-family houses were calculated for this study. The buildings have different wall insulations, claddings, window frames, and roof materials, and the length of the service life varies from 60 years up to 160 years. The current situation and the future of the environmental assessment of buildings are discussed. In addition, topics for further research are suggested; for example, how workmanship affects the service life and the environmental impact of a building should be studied.
Minimizing the use of energy is a central task in sustainable building. Minimizing the use of natural resources and maximizing the recycling potential are other important tasks to take into consideration. In low-energy buildings, the embodied energy accounts for a considerable part of the total energy use of the building. Therefore, it is also imperative to pay attention to the choice of building materials used. This article presents how material choice may affect both embodied energy and recycling potential in one of the most energy efficient apartment-type housing projects in Sweden (calculated energy for operation is 45 kWh/m2 floor area per year). Initially, the embodied energy was 40% of total energy needed for a lifetime expectancy of 50 years. Through material substitution, the embodied energy can be decreased by approximately 17% or increased by about 6%.
The UK government set itself a 60% reduction of carbon dioxide emissions target on 2000 levels by 2050. This commitment will require carbon reductions to be made by all industries including the housing sector which presently accounts for 27% of carbon dioxide emissions. The house building industry is the subject of numerous government policies and legislation, but none are as demanding as the Code of Sustainable Homes, which set a ‘world-beating’ target for all new homes to be zero carbon by 2016. This paper sets out to investigate the feasibility of building zero carbon homes in England by 2016 from a house builder's perspective. A comprehensive opinion of the feasibility of zero carbon homes is gathered through a questionnaire survey and in-depth semi-structured interviews with the major UK housing developers. The research found that there are currently numerous legislative, cultural, financial and technical barriers facing house builders to deliver zero carbon homes in England by 2016. The house builders surveyed concurred that these challenges are not insurmountable provided that a swift, all-embracing and above all realistic strategy is adopted and implemented across the supply chain.
The energy use during the life cycle of three single-unit dwellings built in Sweden in 1991 and 1992 is presented. These houses were prefabricated and their frameworks are made of wood. The purpose of this study is to gain an insight into the energy use for a dwelling during its life cycle. The method used is described in the companion paper “Energy use during the life cycle of buildings: a metho”.
A systematic compilation of 21 different property values of wood and bark fuel was made to facilitate the engineering analysis and modeling of combustion systems. Physical property values vary greatly and properties such as density, porosity, and internal surface area are related to wood species whereas bulk density, particle size, and shape distribution are related to fuel preparation methods. Density of dry wood and bark varies from 300 to 550 kg m−3; bulk density of prepared wood fuel varies from about 160 to 230 kg m−3. Thermal property values such as specific heat, thermal conductivity, and emissivity vary with moisture content, temperature, and degree of thermal degradation by one order of magnitude. The carbon content of wood varies from about 47 to 53% due to varying lignin and extractives content. Mineral content of wood is less than 1%, but it can be over 10 times that value in bark. The composition of mineral matter can vary between and within each tree. Properties that need further investigation are the temperature dependency of thermal conductivity and the thermal emissivity of char-ash. How mineral matter is transformed into various sizes of particulates is not well understood.
A life cycle simulation tool has been developed and linked with thermal simulation. Inventories given in the Oekoinventare database or collected in the European REGENER project are considered to evaluate the environmental impacts of material fabrication and other processes (energy, transport, etc.). An application of this tool is presented here concerning the comparison of three houses: the present construction standard in France (reference), a solar and a wooden frame house. The results of this exercise are presented and its limits are discussed. It seems still difficult to apply life cycle assessment (LCA) to the selection of materials and components. Rather, LCA can be used for the improvement of technical solutions (e.g. increasing the roof insulation in the solar house).
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