Klimatdeklarationer och byggnaders miljöpåverkan : Utvärdering av byggnaders miljöpåverkan utifrån krav på klimatdeklaration: En fallstudie

Sammanfattning: In January 2022, a new requirement will be introduced for declaration of building’s carbon footprint, which is a comprehensive requirement compared with previous regulations. This will hopefully lead the industry in the direction to achieve a net zero carbon footprint by 2050. This study explores the challenges and opportunities of this new requirement to serve as an approach to make more environmentally friendly choices. Many companies currently lack relevant knowledges to perform and evaluate building’s carbon footprint and thus may find this requirement challenging. The purpose of the study is to motivate construction companies and explore the benefits of this requirement in reducing CO2 emissions. This research work is focused on a building case which was built recently by a small construction company. The company runs by some craftsmen and it can therefore be a challenging task to understand and fulfil this requirement. In this study, a life cycle analysis is performed using the documents and materials obtained from the construction company. The declaration requirement concerns mainly the materials used in the building envelope as well as interior walls and load-bearing structures. The requirement is set on the CO2 emitted from production of building materials and components off-site along with on-site production of buildings (i.e. modules A1-A5 in a building's life cycle). The same scope is also applied in the study to analyze CO2 emissions. The analysis was performed in accordance with the recommendations of the Swedish National Board of Housing, Building and Planning, in the OneClickLCA (LCA tool) and by using specific data (ie environmental product declarations) and also more generic data that best represented the case. The results showed that modules A1-A5 were contributed to approximately 94.8 kgCO2e/m2 floor area. The materials with order of high to low CO2 emissions were respectively metal, insulation, wood and gypsum boards. Replacement of the insulation and gypsum boards to more environmentally friendly alternatives provided significant carbon footprint reductions. In addition, the CO2 emissions caused by the transport of wood materials could be reduced through replacement to more local alternatives. As a result, the new scenario which adopted all these alternative solutions could result in approximately 77.68 kgCO2e/m2 floor area which was almost 18% lower than the CO2 emitted from as-built design of the building case.   The conclusion of the study could be summed up that (1) there is an environmental benefit by using locally produced materials, (2) significant reductions in carbon footprint could be obtained by replacing materials to more environmentally friendly ones, which were also produced locally. All these indicated that the requirement on climate declaration can form the basis for making more conscious choices and reduce the carbon footprint of buildings from a life cycle perspective.