Pleun Bertrams, Michiel Jongmans & Jochem de Ruijsscher

Pleun Bertrams (left) en Jochem de Ruijsscher (right)

Affordable and sustainable homes, combined with the maximum preservation of biodiversity. At Bosplaats Thijsse, people live together with nature. “It is a complex, challenging, distinctive and educational project, in which we share core values and ambitions with diederendirrix,” say Pleun Bertrams and Michiel Jongmans of CRA Vastgoed.

Normally, client CRA Vastgoed knows exactly which tenders are coming up. This time, however, it was diederendirrix that called Pleun Bertrams, Head of Acquisitions at CRA Vastgoed, about the municipal tender for the “Development of the School Strip on Bram Streeflandweg.” Whether this assignment could be of interest to them? Diederendirrix saw an opportunity to realise a biobased plan together. The project involved the design of sixty to eighty affordable homes with maximum preservation of biodiversity on a former, overgrown school site between Heelsum and Renkum, an ecologically valuable area within the rolling historic Veluwe landscape.

“This project fits us perfectly. It aligns seamlessly with our field of expertise and our core values,” says Managing Director Michiel Jongmans. “CRA Vastgoed positions itself emphatically through a sustainability strategy in which nature-inclusive and biobased construction are central. This far from conventional development project offers the opportunity to further strengthen our knowledge and experience in these areas.”

Shared Ambition

Family-owned company CRA Vastgoed was keen to participate in the tender together with diederendirrix — which they ultimately won. “We have a long-standing collaboration with diederendirrix on projects such as Roserije Kwartier in Maastricht, De Bankier in Tilburg and De Jonkvrouw in Geldrop,” says Bertrams. “We know each other well, enjoy working together, trust each other’s expertise and immediately understand the direction the other wants to take. In addition, we share a strong substantive drive and ambition, with diederendirrix demonstrating a great sensitivity to quality and context.”

Living with and in Nature

“As a socially engaged area developer, with Bosplaats Thijsse [the name refers to Dr. Jac. P. Thijsse — writer, teacher, conservationist and namesake of the school site], we aim to create a place where people and nature coexist,” says Bertrams. “A place focused on nature conservation, strengthening the local ecosystem and fostering community.”

Sustainable development is about working with what is already there and designing with awareness of energy and materials. This proved to be surprisingly complex. “Together with diederendirrix, we entered partly unfamiliar territory, which turned out to be a valuable learning experience. It is by no means a standard development project,” says Bertrams. “Bosplaats Thijsse is not a neighbourhood of streets and houses with back gardens; here, you truly live with and in nature.”

The challenge lay in balancing quality, requirements and financial feasibility — between the ambition for a regenerative plan, regulations and assessment criteria, and keeping the homes affordable. Diederendirrix designed a progressive scheme comprising 64 homes (10 private-sector homes, 34 affordable owner-occupied homes and 20 social rental homes), distributed across three ‘forest chambers’. The (underground) parking solution proved to be a determining factor for both the landscape quality and the project’s financial viability. Although eighty homes formed the upper limit, a conscious choice was made for a less-is-more approach.

“Diederendirrix is a renowned practice with a strong reputation throughout the Netherlands,” says Bertrams. The architects approached this balancing act with creativity and flexibility. “They are not confined to a single way of thinking and are able to communicate a narrative with conviction — designing something distinctive and exceptional,” Bertrams explains.

“To respond to such a complex combination of factors, you need a partner who thinks in the same way, adapts smoothly and continuously coordinates with all parties involved,” adds Jochem de Ruijsscher, area developer at CRA Vastgoed, who became involved in the project immediately after the tender phase.

Multidisciplinary Team

Landscape architect Buro Harro designed a plan that strengthens the existing green structure, with approximately 130 new native trees and shrubs. The result is a truly diverse forest landscape — a wild fragment of the Veluwe with inhabited ‘forest chambers’ — that meets all requirements, including accessibility.

Together with the contractor and engineering consultancy Volantis, the selection of structural systems and biobased materials, such as CLT, was technically developed and aligned with the established KPIs.

Three Ambassadors

During the tender phase, the team had already carried out extensive research, including studies into the reuse of materials from the existing buildings and the plant and animal species present in the area. An inventory map of recoverable materials was compiled, and, based on the Municipality of Renkum’s Biodiversity Assessment Framework, an ecological vision was developed.

Ecologist David de Vos worked with three ‘ambassadors’: the squirrel, the speckled wood butterfly, and the smooth newt. By designing the area to suit these species, many other animals would automatically benefit as well, including hedgehogs, insects, birds and bats, he explains.

Reflecting on One Another

“From the tender phase to the planned start of construction, our shared conviction about what we want to create, why we are doing it and what we will leave behind has remained intact. We continuously reflect on one another to ensure we do the right thing in the most efficient way,” says De Ruijsscher. “And we will certainly call each other again when another exceptional project comes along,” Bertrams concludes.

Written by: Viveka van de Vliet