'Grey energy' from reusing building materials could significantly reduce waste, study says

A Swiss study has shed light on the efficiency gains of so-called “grey energy” from reusing materials from houses and other buildings, Jürgen Dunsch writes for the Frankfurter Allgemeine Zeitung. Construction is a highly resource-intensive sector but reusing materials such as windows, doors or stone slabs can produce substantial gains in energy efficiency, making buildings a “man-made raw material warehouses,” Germany’s Environment Agency (UBA) says. Barbara Ettinger-Brinckmann, President of the Federal Chamber of Architects (Bundesarchitektenkammer), estimates that grey energy can absorb up to a quarter of the energy required for buildings. Reusing parts of old buildings for new ones is often hindered by the limited uses for the materials, the small volumes that can be extracted, or a lack of assurances about compliance with current standards, the article says.

Despite the barriers, the process is gaining momentum as people become more conscious of energy efficiency, the paper writes. The study by the Federal Office for the Environment in Switzerland said that wood and glass materials topped the recycling list, including materials such as windows, floor coverings and glazing.