Environmental Assessment of Residential Building Renovations

One of the methods utilized for quantification of environmental impacts of human activities is Life-Cycle Assessment (LCA). This dissertation applies the method on renovations of residential buildings in the Czech Republic. The reason is high potential for environmental savings in existing building stock and lack of such works in the Czech conditions. Therefore the dissertation deals with LCA of building renovations to increase the knowledge in this field. Moreover it also questions and evaluates accuracy of building LCA in general to increase understanding of differences and inaccuracies that are often admitted, but seldom analysed in literature. The dissertation includes five LCAs of two case studies: a block-of-flats in Brno and a terraced house in a nearby village. First case study includes LCAs of the original state and renovation of the block-of-flats. The second case study describes LCAs of the original state, partial reconstruction or demolition and new construction of the terraced house. The LCAs are performed in two software tools: Eco-Bat 4.0 and GaBi 4. Detailed models of the evaluated buildings are based on available designs. Environmental impacts are calculated in four impact categories predefined in Eco-Bat 4.0 to enable comparison of results: Ecological Scarcity, Cumulative Energy Demand (or Primary Energy in GaBi 4), Non-Renewable Energy and Global Warming Potential. The accuracy of the performed LCAs is tested in up to 324 different scenario combinations considering variable service life of building materials, construction waste quantities, waste management and transport distances. Generally, the results confirm environmental efficiency of building renovations. The renovation of block-of-flats results in 17.39% average reduction of total environmental impacts. Demolition and new construction of the terraced house result in 76.83% average savings. However, the variation of results is rather high due to tested scenario combinations: up to 56.06%