The RE4 project is a research project funded by European Union’s Horizon 2020 programme where a consortium of 13 research and industrial organisations from 8 different countries (Fig. 1) came together to deliver innovative ecofriendly solutions for the construction market from sorting, recycling and reuse of Construction Demolition Waste (CDW). The project promotes new technological solutions for the design and development of structural and nonstructural prefabricated high-quality elements with high degree of recycled materials and reused structures from CDW. “The main purpose is to develop a RE4 prefabricated energy-efficient building concept that can be easily assembled and disassembled for future reuse, containing up to 65% by weight of recycled materials from CDW”[1].