In Lanaken, the roof of a public housing unit was renovated and insulated—all while remaining in place! For this unique pilot project, Wonen in Limburg, Biesmans Group V&B Dakwerken joined forces. Innovation and creativity came together to produce this outstanding result: an energy-efficient and circular roof renovation at a low cost, with minimal disruption to residents.
Need for affordable housing
The pressure on the housing market is high. While the number of building permits for housing is at its lowest level in 22 years, the demand for energetic and affordable housing continues to grow. In Belgium, 75,000 housing units should be added each year until 2030 to meet housing demand.
Investing in sustainable renovation is therefore becoming increasingly important. This is all the more true for social housing. Because finding affordable housing solutions is a huge challenge, the waiting lists testify to that.
Leveraging existing materials for affordable housing
As part of this initiative, Wonen in Limburg (WiL) renovated a home in Lanaken, a unique project with no precedent. The existing EPDM roofing, which had been on the roof for nearly 20 years, was reused. The ballast (gravel) was moved to one side of the roof, the EPDM was loosened and rolled up. This allowed for the installation of additional insulation. The EPDM was then replaced and secured to the roof edge using Certefix, a component of the BossCover System. The ballast was replaced. The other side of the roof surface was then treated in the same manner.
Certefix is a system Biesmans Group by Biesmans Group in which the EPDM membrane is snapped into place in the roof edge without the use of adhesive. This ensures that the roof remains fully removable for future use.
The works were carried out by V&B Roofworks. Manager Gerry Briers is proud of the result: "The work progressed quickly because the ballast and the EPDM remained on the roof. The residents experienced minimal disruption."
Filip Biesmans, director of Biesmans Group, adds: “Scientific research confirms that EPDM has a service life of at least 70 years. So you don’t just throw away a 20-year-old EPDM membrane! Thanks to the BossCover System, we can install the EPDM membrane as a loose-lay system and reuse it in the future.”
William Nelissen, WiL's technical innovation expert confirms, "The EPDM was still perfectly usable technically. By reusing it, we limited waste and reduced costs. And at the same time, we created a sustainable, circular roof. And that is exactly our mission".
EPDM repurposed: more durable, lower cost, fast execution
The decision to reuse the existing EPDM roof waterproofing led to a successful trial run:
The circular roof structure proved significantly more economical than a complete renovation, accounting for an 18% savings.
In addition to the financial benefit, the implementation also proved to be practically more efficient. Thanks to the light weight of the additional insulation, it could be brought up by hand, eliminating the need for a mobile crane. Moreover, the existing EPDM layer and shingles did not have to be removed or transported from the roof. The residents were satisfied with the result: the site did not cause any nuisance in the garden and the lawn was not damaged.
One of the questions yet to be examined concerns the legal aspect of reuse. In principle, when renovating with new materials, a 10-year warranty period applies again. How do we address this when reusing materials that are already 20 years old? In this particular case (a 98 m² roof), the risk was considered manageable, thanks in part to the high level of confidence in the EPDM material. Moreover, several techniques exist today to test the waterproofing of a roof. On a larger scale, this remains a focus for the further application of circular principles in the construction industry.
This realization shows that circular construction is not only more sustainable, but also economically attractive and technically feasible. The project is thus a powerful example of how smart choices can make the construction sector more sustainable.
The project in Lanaken was an initial trial, but it will certainly be continued. Wonen in Limburg and Biesmans Group now Biesmans Group how this circular approach can be rolled out more widely.
About Living in Limburg
Wonen in Limburg (WiL) is the housing association for those looking to rent, buy, lease, or take out a loan for social housing in the province of Limburg. As part of its mission—“Together, we create sustainable and affordable housing solutions throughout Limburg”—WiL actively seeks out sustainable and innovative renovation solutions. By collaborating with partners such as Biesmans Group , Wonen in Limburg Biesmans Group not only to improve the existing housing stock but also to integrate circular principles into the social housing of tomorrow.
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