REuse, REcycling, Refabricated and Refurbishment
The construction sector is responsible for the largest waste stream in Europe, generating approx. 800 million tonnes of Construction and
Demolition Waste (CDW) every year. The EU Waste Framework Directive 2008/98/EC requires of all member states to achieve 70% reuse,
recycling or other recovery methods of non-hazardous CDW by 2020.
In response, an international team of researchers and experts developed an innovative, holistic RE4 design for a 100% prefabricated, energyefficient,
seven-storey residential building, constructed from reused elements, with an average of 80% recycled CDW materials. The concept
can be adapted to specific project requirements, including office buildings. Recycling rates for structural concrete were increased by 100%
through innovative sorting and the successful handling of varying incoming CDW qualities, whereas a new approach for waste wood handling
led to 80% to 90% higher replacement rates of structural timber. Furthermore, RE4 showcases a solution on how to construct a fully dismantlable
and reusable building so that future generations of waste are limited to a bare minimum. Proof of concept was delivered by constructing
two two-storey demo buildings, one in the cold and one in the warm European climate. The developed solutions reduced the environmental
impact by 38% to 64% respectively in comparison to conventional ones.
RE4 has been developed while accounting for market expectations and scientific aspirations to find a suitable balance between stakeholder
requirements and the developed technical solutions.