Circularity of existing aluminium unitised curtain wall facades

Abstract

The circular potential of existing aluminium curtain wall facades is investigated in this study. The focus is primarily on reuse, refurbishment and re-manufacturing, aiming to raise the value of materials that have not yet reached the end of their service life. The increasing concern about resource depletion, damage to the ecosphere and the need for sustainable development increases the demand for sustainable strategies in many industries. The building industry is one of the most polluting industries at current times and with governments incorporating laws regarding these topics, the need for methods to reduce the impact in this industry is needed. Facades have a great impact on the whole life carbon impact of a building and show potential for reuse. Scheldebouw, a facade producer in the Netherlands, connected to Permasteelisa, is looking for possible ways to make the construction industry more sustainable. This study aims to reduce the take-make-dispose culture, by creating circular strategies for existing curtain wall facades. It was observed that those facades lose their function before their end-of-life stage is reached. The remaining value and potential that was wasted in this case could be avoided.
The objective of this thesis is to develop strategies to reuse existing aluminium curtain wall facade elements, to diminish waste and reduce resource depletion. To quantify the impact of these strategies the life cycle analysis is used to calculate the amount of emitted carbon. A mixed-method research was conducted, which involved integrating interviews with experts in the facade and material industry along with a review of literature, resulting in the development of a qualitative understanding. Integrating this with reference studies, the application of reuse was further examined. Lastly, strategies have been formed, which have been applied to a relevant case. Facades do have the potential for reuse, as demonstrated in this study. Facades play a crucial role in enclosing indoor spaces, which leads to various specific characteristics that make both facade structures
in themselves and in their reuse rather complex. Facade systems are often uniquely developed, making it difficult to locate a match for reuse. Eight general strategies have been defined to create incentives for reuse. A method for calculating the avoided carbon was created to quantify the potential of the strategies and provide an incentive for clients to include these circular strategies. Overall, the research outcomes offer a framework that has the potential to reduce resource depletion and increase value retention in the facade industry. Crucial elements were determined and components that show potential for reuse were defined. Risks and uncertainties have been identified, as well as the need for
incentives for producers, clients, and policymakers. As mentioned above, finding a receiving project that matches the donor material and designing with these materials still appears to be difficult. Regarding carbon emissions, beneficial strategies were defined. Refurbishment can achieve an 86% carbon reduction with 99% of the materials being reused. Re-manufacturing offers a 49% overall carbon reduction with a 59% material saving. Challenges lie in glazing reuse, particularly sealant and spacer components. Implementing re-manufacturing with glass replacement saves 27% embodied carbon and reduces waste by 21% at the donor building and 28% in the product and construction
stages.