Koldioxidutsläpp för olika stommaterial på småhus i Nordiska länder

Sammanfattning: The construction industry accounts for a large part of Sweden's greenhouse gas emissions and needs to decrease for a greener future according to the Sweden’s part in EU: s climate goals. The construction industry accounts for 20% of the total greenhouse gas emissions, of which carbon dioxide embraces 70%. The choice of material when building a family house has a major impact on the total carbon dioxide emission for the building therefore, this study examines carbon dioxide emissions of different frame materials of newly built family houses. The different frameworks that are analyzed in this study are wood, concrete and steel, because they are the most common materials when building a family house in the northern countries. In order to map the carbon dioxide impact of the various frame materials, a literature review of existing life cycle analysis will be implemented. The choice of doing a literature review is based on the large amount of previous research works on the carbon dioxide emissions of the frame materials. To present the results, a sample wall is applied. The width and height of the sample wall is one meter while the depth varies for different materials. The sample wall is designed with the intention to visualize the results in the unit “kg CO2/m3”. The study also includes interviews with manufacturers of family houses with the aim of knowing the construction industry`s views of the choice of the frame material with regard to its carbon dioxide emissions. The results show that there is a major difference in carbon dioxide emissions of the frame materials. The wooden frame with a stud dimension 220x45 mm has a carbon dioxide emission of 81 kg CO2/m3. The steel frame with a stud dimension 195x4 mm has a carbon dioxide emission of 209 kg CO2/m3. Finally, the concrete framewith the thickness 150 mm has a carbon dioxide emission of 602 kg CO2/m3. The conclusion is that the wooden frame has the least carbon dioxide emission, which makes it the most environmentally friendly of all the three frame materials. The interviews also show that the wooden frame is the most advantageous when building a new family house. Some companies motivate their choice of wooden framebased on its bright future, while others consider it to be more efficient from the cost and use perspectives.