A new Evaluation Method for the End-of-life Phase of Buildings

Waste from building and construction sector makes up for about half of the total waste. In order to reduce waste, future buildings shall be constructed in a way that they leave little to no waste behind at the end of their life time. In this work a new method to characterize buildings with respect to their deconstruction and recycling potential at the end of their life time is described. An index of recovery is deduced, which enables planers to optimize buildings in the design phase. The new assessment method provides a science-based automated system. It is based on an inventory of building components, which are virtually disassembled into "minimal blocks", i.e. the smallest possible entities which cannot be further disassembled by economically reasonable efforts. For all possible minimal blocks the algorithm provides tabularised scores, depending on current waste-treatment practice including the efforts required for separation and processing. Additionally, waste-treatment methods in development, including their technological stage of maturity and economic readiness for market are considered. Each building is decomposed into minimal blocks rated by this scheme. All rates are then weighted by the thickness of the respective minimal block and aggregated to a building indicator taking into account the area of the components. The new method promises to deliver selective results, which can be applied for the optimisation of building components. In a follow-up project the method shall be implemented as criterion "disassembly, separation and recycling" (4.1.4) in the BNB (Bewertungssystem Nachhaltiges Bauen) assessment system for the sustainability of buildings.