“Windows – repair, renovate, upgrade, circulate?”

Purpose and Objectives

The purpose of the project is to develop a practical and reliable decision‑support tool for the renovation, reuse, or replacement of existing windows. The objective is to provide property owners, consultants, and contractors with improved decision‑making support for resource‑efficient and climate‑conscious choices through structured inventorying, quality assessment, and life cycle assessment (LCA).

Challenge

Windows are resource‑ and energy‑intensive to manufacture new, while at the same time being complex to reuse due to stringent requirements related to energy performance, airtightness, safety, and indoor environmental quality. Today, standardized methods for assessing remaining technical service life and actual performance are lacking, which often leads to functioning windows being replaced unnecessarily. This results in increased climate impact, more waste, and the loss of valuable resources.

Solution

The project addresses the question: When is it most appropriate to renovate, reuse, or replace windows?
The solution is a methodology that combines systematic inventorying, laboratory testing, and life cycle assessment. By validating inventory data through laboratory testing, a robust knowledge base is created and compiled into a guidance document with practical tools. The methodology can be applied in maintenance and refurbishment projects as well as in new construction where reused building products are sought.

Impact

The project is expected to contribute to reduced climate impact, lower resource consumption, and increased reuse of windows within the construction sector. For property owners, this means reduced uncertainty, improved decision‑making support, and potential cost savings. The societal benefits are linked to the Sustainable Development Goals, particularly Goal 11 (Sustainable Cities and Communities), Goal 12 (Responsible Consumption and Production), and Goal 13 (Climate Action), by enabling a more circular and knowledge‑based construction industry.