EVALUATION OF ENVIRONMENTAL INDICATORS OF BUILDING MATERIALS AND RESULTS IMPLEMENTATION TO BUILDING ENVIRONMENTAL ASSESSMENT SYSTEM

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1 Proceedings of the 13 th International Conference of Environmental Science and Technology Athens, Greece, 5-7 September 2013 EVALUATION OF ENVIRONMENTAL INDICATORS OF BUILDING MATERIALS AND RESULTS IMPLEMENTATION TO BUILDING ENVIRONMENTAL ASSESSMENT SYSTEM SILVIA VILČEKOVÁ 1, MONIKA ČULÁKOVÁ 1 and EVA KRÍDLOVÁ BURDOVÁ 1 1 Technical University of Kosice The Faculty of Civil Engineering, Institute of Environmental Engineering Vysokoskolska 4, Kosice, Slovak Republic silvia.vilcekova@tuke.sk EXTENDED ABSTRACT The buildings are long-term investments associated with large environmental impacts over a long duration. The building construction and operation are known to be significant consumer of non renewable energy, contributor to greenhouse gases, waste and other environmental impacts across the world. The development towards sustainability has increased the importance of environmental footprint reduction as design decision criterion. Environmental building assessment tools are most useful during the design stage when any impairment for the pre-design criteria may be assessed and incorporated at the final stage of design development. Incorporating environmental issues such as resource consumption (of energy, land, water and materials), environmental loading, indoor comfort and longevity can help to reduce environmental impacts during entire life cycle of building. The future direction for building design is more responsible attitude and more environmentally friendly s. The paper deals with evaluation of buildings according to the building environmental assessment tool (BEAS) developed in Slovakia. The selection of building materials for structures has significant share of total environmental performance of building and the potential of improvement is analyzed in this paper. By evaluating of large quantity of different material compositions of conventional and alternative environmental suitable structures of building envelope were determined criteria for particular levels of achieving of sustainability, applied in the BEAS. Keywords: sustainability, building materials, environmental assessment, indicators evaluation 1. INTRODUCTION By integrating the building with the site in a manner that minimizes the impact on natural resources, we can maximize human comfort and social connections. The development footprint should enhance the existing biodiversity and ecology of the site by strengthening the existing natural site patterns and making connections to the surrounding site (Sustainable guidelines, 2002). Building sustainability assessment based on a life-cycle approach can offer important long-term benefits for both building owners and occupants (Hikmat et al., 2009), namely: helping to reduce environmental impacts; solving existing building problems; creating healthier, more comfortable and more productive indoor spaces, and reducing building operation and maintenance costs. Life-cycle analysis considers all the inputs and outputs of acquiring, owning, and disposing of a building system. This approach is particularly useful when project scenarios, which fulfil the same performance requirements, but differ with respect to initial costs and operating costs,

2 have to be compared in order to select the one that maximizes net savings (Hikmat et al., 2009; Mateus et al., 2011). In assessing the performance of buildings, the scope of environmental evaluation is widening, marking an evolution from a single criterion consideration, like the economic performance of buildings, towards a full integration of all aspects emerging during the lifetime of a building and its elements. It becomes therefore clear, that Sustainable Buildings is a broad, multi-criteria subject related to three basic interlinked parameters: economics, environmental issues, and social parameters (Dimitris et al., 2009). An environmental building assessment method reflects the significance of the concept of sustainability in the context of a building design process and subsequent construction work on the site. The primary role of the building environmental assessment method is to provide a comprehensive assessment of the environmental characteristics of a building using a common and verifiable set of criteria and targets for building owners and designers in order to achieve higher environmental standards. It also enhances the environmental awareness of building s and lays down the fundamental direction for the building industry to move towards environmental protection and achieve the goal of sustainability (Cole, 1999; Ding, 2008). Different building assessment systems approach this task from somewhat different perspectives, but they have certain elements in common. Most, if not all, deal in one way or another with site selection criteria, the efficient use of energy and water resources during building operations, waste management during construction and operation, indoor environmental quality, demands for transportation services, and the selection of environmentally preferable materials (Trusty and Horst, 2002). One method, Living Building Challenge from Cascadia Green Building Council, requires the building to be net zero site energy. The same performance versus prescriptive distinction is found in the assessment of embodied energy, or the energy required to produce the building (everything from raw material extraction to on-site assembly of the manufactured materials). Most methods award assessment points for following prescriptive guidelines around recycled content, delivery distance, and building reuse. Only two assessment methods Green Globes and CASBEE require quantification of the embodied energy which is done using life cycle assessment (LCA) in order to assess material performance. While there are at least twenty-one LCA tools for buildings around the world, including sixteen in Europe, that can directly quantify the embodied energy of materials and other aspects of buildings. LCAs are not common in industry because they require a lot of time and data. Makers of Green Globes and CASBEE have simplified the LCA process for their users by providing aggregate data, making the LCA less time-intensive and costly but sacrificing accuracy (Bendewald et al., 2013). 2. BUILDING ENVIRONMENTAL ASSESSMENT Slovak building environmental assessment system (BEAS) has been developed at the Institute of Environmental Engineering, Technical University of Košice. The systems and tools used in many countries have been the foundation of the new system development applicable under Slovak conditions. The main fields and relevant indicators of BEAS have been proposed on the basis of available information analysis from particular fields of the building performance in Slovakia and also according to our own experimental experience. The proposal of the main fields results from the quality of the outdoor and indoor environment, nature and landscape conservation, exploitation of natural resources and so on. Building construction is subject to environmental deterioration, hence the proposal of site selection and project planning field is valid in BEAS. In Slovakia, buildings are characterized by high energy consumption therefore their energy performance is also an important field of assessment. Selection of building materials and structures is very significant in term of embodied energy and emissions of pollutants. The reasons for the

3 proposal of these and other fields such as indoor environment, water and waste management are presented in the next sections. BEAS as a multi-criteria system includes environmental, social and cultural aspects. The proposed fields and indicators respect and adhere to Slovak standards, rules, studies and experiments. The presented system has been developed for the design stage of office buildings. This system for Slovakia contains 6 main fields and 52 indicators. For the purpose of system weighting, the analytical hierarchy process (AHP) was used (Vilčeková et al., 2008). The hierarchy structure of BEAS is shown in Table 1. Table 1. Hierarchy structure of BEAS. BEAS A B C D E F A1 A2 B1 B2 C1 D1 D2 D3 E1 F1 A1.1 A1.2 A1.3 A1.4 A1.5 A1.6 A1.7 A1.8 A1.9 A1.10 A2.1 A2.2 A2.3 A2.4 A2.5 A2.6 A2.7 B2.1 B2.2 B2.3 B2.4 B2.5 B2.1 B2.2 B2.3 C2 C3 C4 C5 C6 C7 C8 C9 C10 D1.1 D1.2 D1.3 D1.4 D1.5 D2.1 D2.2 D2.3 D3.1 D3.2 E2 E3 E4 F2 F3 The proposed main fields are: A Site Selection and Project Planning, B Building Construction, C Indoor Environment, D Energy Performance, E Water Management, F Waste Management (Vilčeková et al., 2008). The methodology of the derivation of assessment indicators in BEAS has been performed according to a study (Yang et al., 2010). An indicator list has been derived by a three-step process. In order to establish a comprehensive set of indicators of the building environmental assessment method for office buildings, a combination of reviewing existing methods of building environmental assessment used worldwide, valid Slovak standards and codes, and an academic research paper has been conducted. A three-step process has been conducted in this method. The first step, a full range of indicators relating to the sustainable building efficiency, has been collected through a wide-ranging literature review. In step 2, a draft indicator list has been selected from the full indicator list based on an in-depth analysis. In step 3, a questionnaire survey has been conducted in order to gather comments from experts in order to refine the draft indicators. As a result, a final indicator list has been proposed. 3. ENVIRONMENTAL INDICATORS Assessment of the environmental performances of building materials and products is a complex issue which requires the use of a set of comprehensive criteria (Harris, 1999). The environmental impacts of these materials can be observed, in fact, at several levels: locally, if we look at the effects of activities such as quarrying or at the specific impact of the manufacturing processes (e.g. dust emissions, noise); globally, as a result of the greenhouse gas emissions linked to energy consumption or released during the manufacturing process; also internally, considering the effects on the health of the occupants of the building (Harris, 1999; Niu, 2001). Therefore, a correct evaluation should adopt to a life cycle perspective (Edwards, 2003; Horvath, 2004), considering not only the impact of material production stage (raw material supply, transport, manufacturing of products and all upstream processes from cradle to gate), but also its

4 contribution in the building construction process (transport to the building site and building installation/construction), use phase (energy losses, maintenance, repair and replacement, refurbishment), and finally end-of-life (recycling and disposal, including transport). This study is focused on determination of assessment criteria of environmental indicators such as embodied energy (EE), embodied CO 2 eq emissions (ECO 2) and embodied SO 2 eq emissions (ESO 2) for the purpose of their implementation to BEAS. The criteria for the evaluation of mentioned environmental indicators are determined on the base of alternative material compositions of structures which are assessed in order to identifying the most optimal solutions in terms of environmental sustainability by LCA within system boundary cradle to gate. The most of data were taken from the Austrian LCA database (Waltjen, 2009). The structures are designed for buildings accomplished thermal requirement to year of 2012 (Table 2), low energy buildings (Table 3) and nearly-zero energy buildings (Table 4) in Slovakia. Table 2. Values of environmental indicators for buildings accomplished thermal requirement to EE [MJ/m 2 ] ECO 2 ESO 2 [kg CO 2 eq./m 2 ] [kg SO 2 eq./m 2 ] Table 3. Values of environmental indicators for low energy buildings. EE [MJ/m 2 ] ECO 2 ESO 2 [kg CO 2 eq./m 2 ] [kg SO 2 eq./m 2 ] Table 4. Values of environmental indicators for nearly-zero energy buildings. EE [MJ/m 2 ] ECO 2 ESO 2 [kg CO 2 eq./m 2 ] [kg SO 2 eq./m 2 ] ,48 These results are implemented to evaluation of indicators proposed in the Slovak environmental assessment system BEAS. 4. EVALUATION OF ENVIRONMENTAL INDICATORS IN BEAS In the Table 5 are presented the evaluation of indicators in the field Building construction and sub-field LCA. The criteria of indicators evaluation are determined according to study presented above. The weights of significance of indicators, sub-fields and fields are determined by Saaty method (Krídlová Burdová, 2013).

5 Table 5. Means of assessment of field Building construction, sub-field LCA. B2 LCA 25% B2.1 Primary energy embodied in building 40.00% materials Purpose To ensure using of building materials with a lower value of embodied energy. point weight Indicator The percentage of built-in building materials with lower value of embodied energy. Negative > 1000 MJ/m 2-1 Acceptable The predicted embodied energy of built-in 1000 MJ/m 2 0 Good building materials is: 800 MJ/m 2 3 Best 500 MJ/m 2 5 B2.2 Global warming potential 40.00% Purpose To minimize the production of atmospheric point weight emissions of CO 2 from mining, manufacturing, transport and construction of building that may result in global warming potential. Indicator CO 2 equivalent in kg per unit net area. Negative > 80 kg/m 2-1 Acceptable The predicted emission from non-renewable 80 kg/m sources of CO 2 equivalent in kg per unit area 0 Good net: 60 kg/m 2 3 Best 40 kg/m 2 5 B2.3 Acidification potential 20.00% Purpose To minimize the production of atmospheric point weight emissions of SO 2 from mining, manufacturing, transport and construction of building that may result in acidification. Indicator SO 2 equivalent in kg per unit net area. Negative > 40 kg/m 2-1 Acceptable The predicted emission from non-renewable 0.40 kg/m sources of SO 2 equivalent in kg per unit area 0 Good net: 0.30 kg/m 2 3 Best 0.20 kg/m CONCLUSIONS The selection of building materials for structures which has significant share of total environmental performance of building and the potential of improvement is analyzed in this paper. By evaluating of large quantity of different material compositions of conventional and alternative environmental suitable structures of building envelope were determined criteria for environmental indicators such as embodied energy, embodied CO 2-eq emissions and embodied SO 2-eq emissions. The criteria for the evaluation of

6 mentioned environmental indicators are determined on the base of alternative material compositions of structures which are assessed in order to identifying the most optimal solutions in terms of environmental sustainability by LCA within system boundary cradle to gate. The determined criteria of mentioned environmental indicators are implemented to building environmental assessment system BEAS used in Slovakia. REFERENCES 1. Bendewald M., Zhai ZJ. (2013) Using carrying capacity as a baseline for building sustainability assessment. Habitat Int., 37, Cole R. J. (1999) Building environmental assessment methods: clarifying intention. Build. Res. Inf., 27, , 3. Dimitris A., Giama E, Papadopoulos A. (2009) An assessment tool for the energy, economic and environmental evaluation of thermal insulation solutions, Energ. Buildings, 41, Ding D.K.C. (2008) Sustainable construction The role of environmental assessment tools. J. Environ. Manage., 86, , 5. Edwards S., Bennett P. (2003) Construction products and life-cycle thinking. UNEP industry and environment, 26, Harris DJ. A (1999) A quantitative approach to the assessment of the environmental impact of building materials. Build. Environ., 34, Hikmat H. A., Saba F. A. N. (2009) Developing a green building assessment tool for developing countries Case of Jordan. Build. Environ., 44, Horvath A. (2004) Construction materials and the environment. Annual Review of Environment and Resources, 29, Mateus R., Braganca L. (2011) Sustainability assessment and rating of buildings: Developing the methodology SBTool PT H. Build. Environ, 46, Niu JL., Burnett J. (2001) Setting up the criteria and credit-awarding scheme for building interior material selection to achieve better indoor air quality. Environ. Int., 26, Sustainable guidelines. (2002) Environmental Stewardship Committee. URL: Trusty W.B., Horst S.W. (2002) Integrating LCA Tools in Green Building Rating Systems. The Austin Papers: Best of the 2002 International Green Building Conference. 13. Vilčeková S., Burdová E. (2008) Building environmental assessment and rating. In: Selected Scientific Papers. 3, No. 1, Krídlová Burdová E., Vilčeková S. (2013) Building environmental assessment system in Slovakia. Saarbrücken: LAP LAMBERT Academic Publishing, Waltjen, T. (2009) Passivhaus-Bauteilkatalog, Ökologisch bewertete Konstruktionen. Springer, Wien, Austria, 347.