Reuse-Woodhouses – Approaches to Circularity for prefabricated Timberhouses

Abstract

This contribution focusses on recent efforts toward fundamental understanding about strengths, weaknesses, opportunities, and threats of the reuse of prefabricated components (walls, slabs) from existing prefabricated residential building. While the typical usage time of prefabricated timber detached houses can be observed to be 30 to 50 years, the Austrian standards that define rules for timber house construction stipulate 100 years of lifetime for such houses. As of today, such buildings are demolished rather than demontaged and reused. We believe that there is large potential for reusing of timber house components, given that such factory-made components follow an industrial production and mounting procedure, which could easily be extended toward deconstruction / demounting. However, to emphasize the circular use of these components, we observed the reuse of a detached house originally erected in a demonstration settlement for potential purchasers. This building was sold, deconstructed and 1:1 re-erected on the site of a client. This case alone, however, would not justify a in-depth implementation of circular economy approaches into production, construction and business procedures. Rather, the demounting and reassembling should happen with different components of different houses. Toward this end, the following aspects require attention: (i) Design for Deconstruction of Buildings and Components; (ii) a stringent data repository offering information about demounted and ready-for-reuse components; (iii) Know How of required (thermal, acoustical, fire safety) updates the components should be subjected to; (iv) Development of a business model that would clarify who should offer the reuse of prefabcomponents in future, (v) Clarification of potential legal liability issues, organizational aspects, and end-user acceptance, as well as approximation of the ecological and economic impact of the reuse of prefabricated timber components.