Opportunities and barriers to pre-assembled and/or pre-casted systems in retrofitting actions

The introduction of severe requirements concerning energy efficiency, combined with the need to boost retrofitting actions while reducing time, impacts and costs, offer new fields of action for pre-assembled and dry construction systems in the building sector, especially in the refurbishment of the residential stock. This paper describes the initial results of a study run by a research team of the University of Bologna, Department of Architecture, concerning this topic. The study was carried out in two stages: the first investigated the barriers affecting the application of preassembled and/or pre-casted systems to retrofitting, such as law, technical and geometrical constraints; the second investigated the most effective solutions to be pursued. The following factors were key drivers for the refurbishment techniques: lightweight of components and systems suitable when a small residual loading capacity is still available; open implementation process, aimed to allow further upgrade in a future stage; controlled and monitored construction process; strong reduction in construction time as well as in the environmental impacts of the building site. The paper describes how pre-assembled systems could be adapted to the constraints of existing buildings, while offering the benefits and advantages of an effective management during both the design and construction phase.