Potential of existing prefabricated components for sustainable renovation of buildings

Since 2015, energy performance requirements in Flanders (Belgium) also apply to existing buildings undergoing major renovation works. In this context, prefabricated façade components have a large potential for renovating the existing building stock in a fast and repeatable way. Benefits of this technique are functionality during renovation works, possibility of integrating HVAC systems and the limited number of activities on site. On the other hand, the preparatory work is more extensive and there is a lack of experience with the application of prefabricated components in renovation projects. Consequently, prefabricated systems are seldom applied. A recently started research project aims to stimulate the development and use of these systems by providing tools that permit to make a founded assessment of the effectiveness of prefabricated systems: a decision tool, a cost calculator and technical solutions including air- and watertightness, acoustics, fire safety and guidelines for a minimal risk on hygrothermal damage will be developed. This paper can be seen as a first step: an overview of the multiple systems that are described in commercial and academic literature is presented. The paper not only elaborates on timber frame systems, which are most frequently used, but also modules constructed of cold formed steel, composite and concrete systems are discussed. Next to that, a first test set-up in the research project, focussing on the air- and watertightness of wide junctions, is discussed. The main purpose of the test is to compare several existing systems for the creation of an airtight layer at the exterior surface. In the future, this test will be executed and other research scenarios will be elaborated