Byggnadsmaterials klimatpåverkan med avseende på koldioxidutsläpp : under materialproduktion och byggnadens energianvändning, fallstudie av Kungsängstorg

Sammanfattning: The largest contributor to global warming from the construction and real estate sector comes from the emission of greenhouse gases during the production and usage phases of buildings. During production the leading contributor accounting for emissions is material production while the largest impact in the usage phase is due to energy used for heating, where the largest heat losses occur through building envelopes. Therefore, should the material selection for the building envelope be optimized both regarding the materials lifetime pollutant emissions as well as its effect on energy consumption during building use. The purpose of this paper is to review materials carbon footprint regarding its lifecycle and the effect on energy use of different exterior wall constructions during building use. To answer these questions different methods are applied such as case studies, theoretical studies and simulations. Investigated materials and exterior wall constructions are sandwich panels with a core of rock wool, CLT (cross laminated timber) combined with glass wool and CLT combined with hemp fiber insulation. The result of the study indicates that the climate impact from production of the investigated materials is small compared to the climate impact of energy use. However the study shows that the emissions from the production phase differ between materials. CLT combined with hemp fiber insulation or glass wool insulation has less of an effect on greenhouse emissions compared to sandwich panels. Furthermore, depending on the selection of dimensions for CLT and insulation there are possibilities to reduce energy consumption during building use and still maintain a lower level of emission from material production compared to sandwich panels.