Are recycled materials as durable as new materials? To find out the answer, we collaborated on a ground-breaking study of three apartment blocks that were built over 30 years ago using recycled materials.

Between 1990 and 1994, three apartment buildings were constructed in the cities of Horsens, Odense and Copenhagen in Denmark using 80 to 90 per cent of materials recycled from demolition waste.

Three decades later, the buildings’ owners, Realdania commissioned WSP (formerly Golder Associates A/S) and ØLLGAARD Rådgivende Ingeniører A/S to assess the condition of these buildings.  

Through our study we determined that if recycled materials are carefully selected and tested prior to construction, they will have the same durability and properties of similar new materials. Therefore it makes no difference whether the materials are old or new, what matters is their quality.

Maximizing the use of recycled materials for construction is an important step in achieving a circular economy. The results of this study give new insight into these materials and will help to increase confidence in using recycled products on large scale developments. 

The recycled building materials are often mentioned at residents' meetings, which creates joy and social pride, especially among the younger residents.
Copenhagen resident
Marlene Thorman
Denmark

The Recycled Houses – 30 years after construction

Discover how buildings constructed using recycled materials have fared over the past three decades and how the findings support recycling and a more circular construction sector.

Download the report

Appendices

You can read more detail about the project in the appendices:
 
- Quality requirements 
- Interviews with operators and residents 
- Condition assessment – Copenhagen house
- Condition assessment – Horsens house
- Condition assessment – Odense house
- References