In Sweden housing shortage is a rising issue. Within a ten year period scientists predict that the Swedish population will increase from 10 to approximately 11 million people. Due to this increase in the Swedish population, the production of multi-dwelling buildings should be expanding, though instead building development is now decreasing. The Swedish government recently stated upon a climate strategy, to have no excessive emissions of greenhouse gases until the year of 2045. Regarding this climate strategy and the increasing need for housing, the need to build time-efficient, low cost buildings that have minimal environmental impact is in a greater demand than ever before. The purpose of this degree project is to elucidate the environmental effects, costs and assembly time for multi-dwelling buildings with prefabricated wooden and concrete frames. The study, based on literature and interviews, displays that prefabricated cross-laminated timber frames are more expensive than prefabricated concrete frames. However, choosing a timber frame does not necessarily result in a higher production cost compared to a concrete frame. Due to the dehydration time with concrete frames, wooden frames are almost 20 % more time efficient to assemble. Although wooden frames take less time to assemble, they often need more post-production work to withhold quality demands in comparison to concrete frames. The difference in environmental effect between the two materials is significant. Wood is an organic and renewable material and therefore has a low environmental impact. Concrete, which is a non-renewable material, has a higher environmental impact because of its cement component. Today 90 % of the newly developed multi-dwelling buildings are constructed with concrete. To reach the climate strategy in 2045, an increase of wooden constructions is one solution to lower the greenhouse gas emissions. Regarding that most of today’s construction building companies are using concrete as their primary frame material, this way of construction will have to change. Due to this future change, a decisionmaking model for selecting framework material has been developed. The model aims to guide clients and construction companies in an early process to get a first indication on what type of material that would be most beneficial to use in a project. The model is based on three different key factors; environmental effect, investment cost and time. When using the model, these key factors will be compared to each other and prioritized in a hierarchy setting. The outcome specifies the most preferable material to use in a project.