The Marnix, Brussel: Deck‑VQ vacuum insulation as an effective solution

Photographer: Ulrich Schwarz

Architect: Moreno, A2M Architects

Contractor for Roofing Works: ZDP Sud

In contemporary renovation projects, space is often the most scarce resource. You want efficient insulation, but on flat roofs, roof terraces, and floors, the available construction height is rarely unlimited. This is precisely why Deck-VQ® vacuum insulation offers an interesting, high-performance solution: Deck-VQ combines an ultra-thin construction with exceptional thermal performance. In the Brussels project The Marnix, this advantage was maximized.

Preparing an Iconic Building for the Future

The Marnix is an iconic building in Brussels that has been thoroughly and sustainably renovated over several years. The ambition went beyond mere energy efficiency, starting from a broad vision of transparency, well-being, art for everyone, and innovation and sustainability. This comprehensive approach is reflected in high certification objectives, including BREEAM Outstanding and WELL Platinum as clear benchmarks.

When Every Millimeter Counts: The Challenge of Limited Construction Height

Flat Roof Renovation: Insulation Without Height Loss

In the renovation of a flat roof or roof terrace, the construction is often defined by existing thresholds, door heights, and connections. Additional insulation thickness can then lead to issues with drainage, upstands, and the risk of thermal bridges. Therefore, it is crucial to think about a solution that combines high efficiency with a limited roof construction already during the design phase.

During renovation and repurposing, there is often a tension between stricter energy requirements demanding more insulation, while the available space is limited. Especially for roof terraces and outdoor spaces, height differences, thresholds, railings, drainage, and connection details play a crucial role. In The Marnix, there were areas where the construction height was so limited that traditional solutions would quickly lead to compromises in comfort, thermal performance, or architectural quality.

Deck-VQ Vacuum Insulation as a Performance Solution

VIP Panels (Vacuum Insulated Panels): Ultra-thin Insulation with an Exceptional Lambda

The roof terraces of The Marnix were chosen for Deck-VQ®: a solution with VIPs (Vacuum Insulated Panels) that insulate 5 to 10 times better than traditional materials. The core of a VIP consists of fumed silica and is encapsulated under vacuum, resulting in extremely low thermal conductivity (λ 0.006 W/mK in the core). This performance allows for an ultra-thin build to still achieve a high level of insulation: ideal when space is limited, but the standards are high.

To make the panels robust and workable in practice, the VIPs are integrated into high-density PIR boards. This protects the vacuum core during transport and installation, allowing for safe handling on-site. Additionally, Recticel always creates a layout plan with Deck-VQ® tailored to each project and assists designers and contractors with detailing and correctly integrating the solution.

What architects or construction professionals can take away from The Marnix

• Map out critical height zones early: thresholds, connections, drainage, railings, and existing structures determine where ‘traditional’ insulation hits a snag. In such situations, Deck-VQ vacuum insulation is a problem solver.
• Use Deck-VQ vacuum insulation strategically and exactly where millimeters make a difference. This way, it is still possible to achieve the required thermal performance.
• Combine smartly: in complex renovations, a hybrid construction (e.g., vacuum insulation in critical zones, supplemented with other insulation where more space is available) can deliver a strong overall result. A combination of Deck-VQ vacuum insulation with sloped insulation is also possible.
• Detail with confidence: with project-specific layout plans and technical support.