Life cycle assessment of prefabricated timber frame 'open-renovation-systems' for rooftop extensions

摘要

Compact building design is a key challenge in Flanders. Additional housing is required due to the growing Flemish population combined with decreasing household size. Seen the current problems of urban sprawl, densification of the current residential area offers a solution to address these extra housing needs and to avoid further fragmentation of remaining valuable open space. Therefore, the emphasis in this research is on designing and evaluating affordable and innovative ‘open-renovation-systems’ for low-energy rooftop extensions on residential buildings. In preliminary research, a screening of a current Belgian timber frame system for a rooftop extension has been made at both the element and building level through a life cycle assessment. The wooden based parts of the timber frame were identified as hotspots. This paper builds further on these results and focuses on how to reduce the environmental impact of prefabricated timber frame renovation systems. The results of this paper show that optimizing the wooden sections in timber frame walls by means of using I-joists instead of solid studs can slightly reduce the environmental impact. Furthermore, this study confirmed that the modelling of the wood preservatives has an important influence on the results and hence a correct modelling is necessary.