Renovation for the future An investigation of environmental impact and lifecycle costs from design choices during a renovation project

Abstract

Many of the buildings made in the 1960s to 1970s are today in urgent need of renovation. To be able to reach the goal of net-zero emissions by 2045 they are also in need of improved energy efficiency. While decreased energy usage after renovations leads to lower environmental impact, it also leads to long-term lower costs. With selection of lasting materials, it is also possible to lower the cost for maintenance. By performing life cycle assessments (LCA) and life cycle costs (LCC) on different design options of a future renovation project, this thesis investigates the interrelation between building costs and environmental impact alongside architectural qualities. The thesis focuses on the renovation of an apartment building in Gärdsås in Gothenburg, where renovations have been initiated on buildings of the same type. Data from the already performed renovations will be used as reference for further investigations on one of the buildings that is still to be renovated. The previous renovations affected the facades and outside areas, and the future renovations will be including a pipe exchange and renovation of bathrooms. These actions together with the façade renovation means that the tenants must be relocated during the renovation and more extensive renovations performed. This thesis aims to present an alternative to this renovation where the design choices are motivated by the result of the cost and environmental assessments. Previous studies show that there is currently a lack of models to consider long term economical gain in public renovation projects. Since public housing companies have a larger responsibility to be socially sustainable, the balance between economical gain and increased rents becomes vital. Life cycle assessments show in a holistic way the climate impact of a building over its lifetime and can be used in an early design process to investigate different options. By simultaneously investigating life cycle costs, this thesis aims to motivate sustainable solutions with lower long-term costs over a building’s lifetime. Additionally, the thesis aims to provide a basis for further discussion on the responsibility for renovation costs.