Reuse and Recycling of construction and demolition waste
Innovative prefabricated elements with high degree of recycled materials
Reuse structures from demolished buildings
Minimize environmental impacts in construction industry
Develop a RE4-prefabricated energy-efficient building concept
Developing of prefabricated components that can be easily assembled and
Disassembled for future reuse

Project Background and Purpose

The main purpose of project is to develop a RE4 prefabricated energy-efficient building concept that can be easily assembled and disassembled for future reuse, containing up to 65% in weight of recycled materials from CDW (ranging from 50% for the medium replacement of the mineral fraction, up to 65%). The reusable structures will range from 15-20% for existing buildings to 80-90% for the RE4 prefabricated building concept.

Approximately 750 million tons/year of CDW is generated in Europe Recovery rate below 50%

Construction and demolition waste (CDW) is one of the priority targets of European Commission, because of the large volume of generated waste and its high potential for re-use and recycling. Moreover, a negligible percentage of waste is destined to reuse mainly because the majority of the existing buildings was not designed for disassembly and reuse.

So the mission of the European Union is very clear

  • increase the percentage of recycled materials and reused structures from CDW
  • increase the technical and economic value of CDW-derived materials and structures
  • minimize future CDW coming from the next generation of buildings
  • increase the building energy efficiency

RE4 project aims to promote new technological solutions and strategies for the development of prefabricated elements with high degree of recycled materials and reused structures from demolished buildings. The main aim of the project is to develop energy efficient building produced from CDW, thus minimize environmental impacts in construction industry.

The building component will be suitable for both new construction and building refurbishment. The final building design will be used to demonstrate the developed solutions and support the dissemination of the project. The demonstration activities will be carried out in Spain and Ireland to validate concept indifferent climatic conditions.

Overall concept

The innovation is firstly focused on the development of new sorting technologies. Such first stage of the recycling process establishes the amount of recycled material and also the possibility to properly close the product chain maximizing the product value. Such fraction/material/structure from CDW will be studied and processed with 3 different technologies (casting, extrusion and moulding) and transformed in the new or adapted prefabricated components highlighted in Figure below. The prefabricated component developed in the RE4 project will be finally assembled into a RE4 prefabricated energy-efficient building concept designed for an easy installation and dismantling.

Project objectives

  • Development of innovative design concepts for smart installation and disassembly of the pre-fabricated elements into a prefabricated energy-efficient building unit The concepts will be designed in such way that multiple applications for different building typologies (e.g. residential, commercial) will be easy to implement.
  • RE4 demonstration in industrial environment, testing and evaluation, replication Demonstration of the proposed RE4 solutions for new constructions will take place in two specifically constructed mock-ups representatives of building archetypes across Europe consisting of a two storey building.
  • Enhancement of the sustainability and future applications of RE4 prefabricated products From a quantitative point of view, the following objectives are targeted in relation to: CO2 savings (over 30 %), energy savings (20%), higher resource efficiency (minimum share of recycled materials in final product up to 65 %), less waste generation, less CDW disposal in landfill.
  • Development of a BIM-compatible DSS and platform for CDW estimation and Management A BIM-compatible tool will be developed with the aim of supporting owners and construction/demolition companies by providing an estimation of the types and quantities of CDW that will be generated during construction/demolition, with possible utilization options and related logistic references.
  • Development of business models for industrial exploitation The expansion of size and attractiveness of CDW recycling and reuse for energy efficient buildings construction and refurbishment will promote an efficient value chain, creating attractive business opportunities for the involved stakeholders.


Demonstration of the RE4 solutions will take place in two specifically constructed mock-ups (residential or non-residential demo buildings) in two different climatic regions (UK, Spain). Demonstration of refurbishment solutions will either be realized in a suitable existing building and/or in the demo site available at STRESS. Strategy for disassembly and reuse materials and structures from dismantled buildings will be either demonstrated in a suitable existing building (if available) and/or in the Acciona demo park. Demonstration of the high replication potential of the developed solutions outside EU will be achieved through the construction of a further demo building in Taiwan.

Acciona demo park
STRESS experimental station


25.09.2020 | DGNB Sustainability Challenge winners!

The awards just keep coming! 

The RE4 project won the DGNG Sustainability Challenge 2020 in the “Research” Category!

Good feedback from the awarding authority that was impressed by the complexity of the project, the outstanding results obtained, and the proof of concept, that is quite difficult to see in projects focused on circular economy.

It is amazing to see what an important role RE4 is playing in improving the circular economy in construction. Thank you to all the partners for reaching this goal.

Read more and enjoy!

09.09.2020 | RE4 DNGB Sustainability challenge

The RE4 project has been selected by the Deutsche Gesellschaft für Nachhaltiges Bauen - DGNB e. V. (German Sustainable Building Council) as one of three finalists in this year’s Sustainability Challenge.

The official voting is now online and we would appreciate if you could give us a vote. The voting page is in German, you can make the selection on the right side of the page and click "Jetzt Abstimmen".


The winner will be announced at the conference ‘Day of Sustainability’ on the 21st of September in Stuttgart. We will be presenting our project at the conference and are looking forward to seeing some of you there. Due to the current circumstances, there are only few tickets for the event but you can also register to take part digitally.

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