This article presents the metric avoided carbon for the reuse of aluminium unitised curtain wall façades, that are to be taken from a donor building an applied onto a receiving building. The metric is used to compare seven proposed circular reuse strategies, each showing a different level of reuse. Based on literature and reference studies, we identify those parts of the façade where reuse has the most impact and is technically feasible. The seven reuse strategies and the avoided carbon method are applied on a real case study building as donor project and a fictitious building as receiving project. We conclude that reuse is technically feasible, saves carbon, and that the proposed metric can help to incentivize building owners and project developers to adopt circular reuse.