Livscykelanalys av miljöcertifierat modulelement under produktskedet

Sammanfattning: A major and current problem today is the climate change which has led to melting of sea ice, sea levels rising, heated seas and changing weather conditions. The construction- and real estate sector accounted for 21 percent of Sweden’s total greenhouse gas (GHG) emissions in year 2018. One way to mitigate climate change is to construct modular buildings as these have lower climate impact compared to on-site constructed buildings. The purpose of this degree project is to investigate the climate impact of the product phase of a modular building with Miljöbyggnad Silver environmental certification. To achieve the purpose three questions are answered: which part of the product phase has the greatest climate impact? which measures have significant impact on the climate impact of a building module? and what are the differences in climate impact when comparing building modules with and without Miljöbygggnad Silver environmental certification? The climate impact of two composite modules with a glulam and structural timber frame are analyzed in this report. The gross area of the objects is 50,2 m2 and is a part of an apartment building. The climate impact is calculated as global warming potential of GHG emissions of the object, using a lifecycle analysis methodology. The calculations are done for the product phase which covers raw material extraction, transport and manufacturing. The Construction Sector’s Environmental Calculations Tool (Byggsektorns miljöberäkningsverktyg) and Excel has been used for the calculations, with data primarily from environmental product declarations. The results show that the product phase of the object emits 94,44 kg CO2e/m2, based on specific data supplemented with generic data and Nordic electricity mix. Raw material extraction accounts for the largest share of the climate impact. To reduce the climate impact, gypsum boards and steel products made in Sweden can be chosen and alternative insulation materials such as cellulose fiber can replace mineral wool. The results show that the module that is certified has lower climate impact than the module without certification. However, it is not possible to say with certainty that the differences in the climate impact is because of the environmental certification.