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.

Den globala uppvärmningen har lett till att Sveriges regering, för att uppfylla de globala klimatmålen, har tagit fram ett lagkrav som är tänkt att träda i kraft från 1 januari 2022. Lagkravet innebär att utsläpp av växthusgas ska dokumenteras för byggnader över hela deras livscykel. Syftet och målet med examensarbetet är att undersöka och analysera en modulbyggnads klimatpåverkan under produktskedet. Objektet som undersöks är en byggnadsmodul med bostadsytan 40,6 m2, som ingår i ett större flerbostadshus. Klimatpåverkan har beräknats och analyserats i form av en livscykelanalys med Byggsektorns Miljöberäkningsverktyg. Analysen är avgränsad till modulens produktskede inklusive råvaruförsörjning, transport och tillverkning av modulen. Resultatet av studien är att modulen släpper ut 124,8 kilogram koldioxidekvivalenter per kvadratmeter enligt specifika data. Mest utsläpp av växthusgaserx kommer från materialet korslimmat trä och från energikällorna som används vid tillverkningen av byggprodukter och modulen. / Global warming has led to the Swedish government, as part of the global climate goals, to propose a legislative requirement that is supposed to come into force from January 1, 2022. The forthcoming legislative requirement will stipulate that greenhouse gas emission from buildings' life cycle are documented and presented. The purpose and goal of this thesis is to investigate and analyze the climate impact of a prefabricated building module during the product stage. The object investigated is a building module with a living area of 40.6 m2, which is part of a larger apartment building. The climate impact has been calculated and analyzed with life cycle analysis approach using the Construction Sector's Environmental Calculation Tool (Byggsektorns miljöberäkningsverktyg). The analysis is limited to the product stage of the module including extraction and processing of raw materials, transportation and manufacturing of the module. The result of the study is that the modules climate impact is 124.8 kilograms carbon dioxide equivalents per square meter according to specific data. The major part of greenhouse gas emissions comes from the material cross laminated wood and from energy sources being used in the manufacturing of building products and the module.