The building sector contributes to a large part of the total emissions of greenhouse gases, which demands for increased sustainability in all phases of a buildings’ lifecycle. Choices of building materials and the respective required maintenance and replacements are becoming more important if further reductions of climate impacts should be obtained. Folkhem is a Swedish construction company who constructs multi-storey buildings made of wood. The company has shown interest in developing knowledge about how the selection of building materials effects the impacts on climate, the extent of necessary maintenance and replacement work as well as economic consequences. The aim of this master thesis was to evaluate the potential climate impacts and costs for different scenarios of maintenance and replacements of selected exterior building components for Folkhem’s planned building in Stadshagen, in Stockholm. The façade, roof, windows and balconies have been in focus. To fulfill the aim of this study, life cycle assessment and a simplified cost analysis have been carried out. With the basis of the results from this study, recommendations of building materials for the chosen building components in Folkhem’s planned building have been stated. A façade made of pine impregnated with boiled linseed oil is recommended as façade cladding, and OrganoWood is recommended for the balcony decking. Folkhem planned to use wooden windows, but it is recommended that these are substituted to aluminum coated wooden windows. No recommendation could be provided for the roof from this study. The following conclusions have been made; More attention should be payed to the phases of maintenance and replacement when carrying out LCAs for timber buildings, since general assumptions could be misleading. The origin of the building materials could have a significant climate impact if several replacements need to be performed, since this includes a large number of transports of materials. Different building materials or building components have different lifespans and needs for maintenance. To reduce costs and potential climate impacts, long lifespans with little need for maintenance are desired. Planning for a specific lifespan of the building and the required maintenance and replacements may contribute to reduce the potential climate impacts. Maintenance is recommended for timber buildings, since this could reduce the need for replacements, which could reduce the potential climate impacts. LCA can be a useful tool for Folkhem to plan for maintenance and replacements of their timber buildings if improvements are performed regarding LCA data quality. LCA can provide guidance for Folkhem to choose sustainable building materials, with regards to maintenance and replacements at an early stage in the design process. A future study could be to perform a more detailed LCA of the materials and products that required assumptions in this study, for instance the surface treatments for maintenance. A more detailed LCA of all maintenance that should be conducted in a building could be of interest as well, and to investigate the impacts from excluded processes in this study. Alternative building materials for the exterior building components could be evaluated as well as different percentages of painting area. More impact categories than climate change could also be evaluated. Impacts from the building lifecycle phases of repair and refurbishment could also be interesting to evaluate in order to receive an overview of the total potential climate impacts and costs from all parts of the lifecycle of a building. Another approach could be to investigate if maintenance and replacement are carried out as described from technical literature and manufacturers in reality. Finally, a more thorough cost analysis could be carried out, evaluating how a housing society would be affected from costs from maintenance and replacement.

I Sverige har byggsektorn en stor påverkan på miljön och nya metoder samt materialen behöver tas fram för att förbättra situationen. Ett online-verktyg kan användas som ett hjälpmedel vid inlärning och även öka kunskapen. Arbetet gick ut på att skapa ett online-verktyg men även att kontrollera hur andra befintliga verktyg fungerar och hur de är utformade.Syftet och målet med arbetet var att skapa ett online-verktyg för träkonstruktioner som kan användas i kursen Stål- och träkonstruktioner samt som kan hjälpa studenter vid inlärning och kontroller av beräkningar.Online-verktyget som tagits fram erbjuder möjligheten att beräkna bärförmågan hos träkonstruktioner i form av balkar, pelare och förband. Online-verktyget befinner sig i ett tidigt stadie och kräver mer utveckling, enkätundersökningar och intervjuer gav inblick till vad som behöver implementeras i framtiden. / The building sector in Sweden has a big impact on the environment and new methods as well as new technology need to be developed in order to improve the situation. An online tool can be used as an aid in learning and to improve the knowledge. The thesis work comprises the development of an online tool and furthermore an investigation of how other online tools work and how they are designed.The goal and the purpose of the thesis was to create an online tool that can be implemented in the course Steel and Timber Structural Engineering at Linnaeus University. In order to help students with learning and to check calculations.The program that has been developed offers the ability to calculate the load bearing capacity of beams, pillars and connections with metal fasteners. The online tool is in an early stage and needs further. The surveys and interviews gave an insight to what functions need to be implemented in the future.

Byggande står för betydande resursanvändning och miljöbelastning. Att bygga i trä är en möjlighet att bidra till ett mer hållbart byggande och de senaste 10 åren har det skett en snabb utveckling av byggsystem och lösningar för flerbostadshus med stommar av trä. Samtidigt når inte alltid kunskap om dessa byggnaders detaljlösningar fram till beställare i byggprojektens tidiga skeden — kunskap som är viktig för ett mer hållbart byggande.  I syfte att öka kunskapen om hur byggtekniska detaljer påverkar en byggnads miljöbelastning så har det här arbetet studerat och dimensionerat byggtekniska detaljer för flerbostadshus med stommar av trä. Med utgångspunkt i de studerade detaljerna har fem byggnader modellerats och deras miljöbelastning utvärderats. Detaljerna har dimensionerats för att klara gällande lagkrav och vanligt förekommande beställarkrav. Byggnadernas miljöbelastning har utvärderats med hänsyn till resurseffektivitet, klimatpåverkan och innehåll av farliga ämnen.  Resultatet visar att krav på luftljudsreduktion, nedböjning av bjälklag, ytterväggens U-värde och brand blir avgörande vid dimensionering.  Utvärdering av byggnaden visar att isolering och stommar i KL-trä är de mest resurskrävande byggdelskategorierna. En av detaljerna bidrar till högre klimatpåverkan per BTA än krav i LFM30 och alla detaljer innehåller farliga ämnen. Några av lärdomarna från arbetet är att detaljer med pågjutning av bjälklag bidrar negativt till byggnadens klimatpåverkan och att dimensionering av detaljer är beroende av en mängd olika skivmaterial. Skivmaterial bidrar till en betydande del av byggnadens klimatpåverkan. Det finns många miljövinster att göra då byggnader uppförs med stommar av trä. Trots detta är det inte självklart att den byggtekniska detaljen är fri från miljöbelastande innehåll och utvärdering måste göras från fall till fall. Förhoppningsvis kan det här arbetet öka förståelsen för vilka faktorer som påverkar dimensionering av byggtekniska detaljer och hur detta i sin tur sitter ihop med byggnadens miljöbelastning, så att nya lösningar kan utformas och bidra till ett mer hållbart byggande. / Construction is responsible for significant resource use and environmental impact. Building with wood is an opportunity to contribute to more sustainable construction. Over the past ten years, there has been a rapid development of construction systems and solutions for residential buildings built with wood. However, knowledge about the construction details of such buildings does not always reach clients during the early stages of project development – knowledge that is important for sustainable construction. With the aim to increase knowledge on how construction details affect the environmental impact of a building, this study focus on construction details for residential buildings built of wood. The environmental impact of five buildings have been evaluated using models based on the studied details. The details were designed to meet both legal requirements as well as clients’ requests. The environmental impact was assessed with regard to resource efficiency, climate impact and hazardous substances. The results show that requirements for sound reduction, deflection of floors, heat transmission and fire are crucial to the design process. The evaluation of the buildings shows that insulation and CLT frames are the most resource-intensive components. One of the details studied contributes to higher climate impact per GFA than requirements in LFM30, and all the details contain a fraction of hazardous substance. Details with casted floors contribute negatively to the climate impact of the building and the design process greatly depends on various sheet materials. Sheet materials contribute to a significant part of the building’s climate impact. Many environmental gains can be made when buildings are constructed in wood. Nevertheless, it is not self-evident that construction details are free from environmentally harmful content and evaluation must be done on a case-by-case basis. Hopefully this study can illuminate factors that influence the design process of construction details and how they are connected to the environmental impact of the building, so that new solutions can be formed and contribute to more sustainable construction. / <p>2023-06-26</p>