To reduce material waste and carbon emissions, the manufacturing industry of exterior window frames (aluminium, PVCu and timber) could transition from recycling to remanufacturing. This paper investigates to what extent reclaimable window frames from 1970 to 2010 are technically upgradable to meet current thermal and airtightness requirements, and if the existing (linear) supply chains are able to perform these upgrades. To answer these questions, a multi-method approach was used. Historic window frame designs were retrieved from standard literature. These were assessed to see what minimum upgrades they require to comply to current regulations. Retrieved process models of the existing supply chains were then used to investigate to what extent the existing factories are able to perform these upgrades. The results show that based on the assessed historic window frames, it is possible to upgrade aluminium, PVCu and timber window frames of around 25 years old, depending on the window size. However, from a remanufacturing perspective, all three existing supply chains lack essential steps to perform these product upgrades. Also some existing manufacturing processes can't be used for remanufacturing, as they are designed to process unencased, individual profiles. This makes reclaimed encased frames incompatible with the first processes of the linear supply chains. PVCu and aluminium profiles are manufactured in respectively two and three factories, which is a notable impediment for re-finishing the profiles. Two identified opportunities for upgradability and remanufacturing are standardization of interfaces and modularity. Future multi-lifecycle circular window frame designs could benefit from further implementation of these design approaches.