Circular demolition
This Replication Package describes the performance of the two CityLoops guides, Pre-Demolition Audit Guide and Guide for Selective Demolition, in total and partial demolition. The purpose of the pre-demolition audit is to prepare for selective demolition by providing a detailed assessment of building material fractions with respect to their amount, quality, purity, and suitability for circularity (reuse, recycling, recovering). The purpose of selective demolition is to sort the demolition materials in clean fractions for optimisation of circularity of the materials, according to the highest level of the waste hierarchy.
The pre-demolition audit guide explains how a pre-demolition inventory and material audit can be conducted to identify building components and materials with reuse or recycling potential. The guide can be used, when planning demolition projects, with sufficient time and coordination among actors, to make a pre-demolition screening (and subsequent selective demolition) required in the procurement of a demolition contractor. The screening procedure aims to recognise reusable and recyclable materials and building elements and to give recommendations for how to handle them. Identification of materials (as containing harmful substances, or as having residual value and potential for other uses) is the key first step to preventing their treatment as waste.
The selective demolition guide explains how a selective demolition can be conducted to select and preserve value of building components and materials with reuse or recycling potential, following a series of chronological steps to dismount components or materials without damaging them. The guide can be used, when planning demolition projects, with sufficient time and coordination among actors, to ensure that selective demolition is required in the procurement of a demolition contractor. The selective demolition procedure guide gives recommendations to manage material removal and treatment. By removing harmful substances and salvaging construction materials with recoverable value, a more circular demolition can take place, thus reducing the total CDW generated on site and creating secondary construction material supply.
Lessons learnt
The two guides have been tested and evaluated in the CityLoops demonstration actions and recommended for replication in all renovation and demolition projects. A general recommendation is that the screening and selective demolition both need to be planned for well in advance and are incorporated when tendering. Once contracted, contractors will not voluntarily carry out the screening – so any foreseen use should be clearly intended in the demolition planning phase.