Bio-based Materials and Indoor Comfort: A Residential Project in Beersel

In Beersel, this single-family house illustrates a coherent approach to sustainable construction, where material choices contribute both to reducing environmental impact and improving indoor comfort. Without aiming for demonstrative effects, the project relies on proven solutions, implemented with rigor.

A hybrid structure with a CLT upper floor

The building is based on a traditional structural system, topped with an upper floor made of CLT (Cross Laminated Timber). This structural choice addresses several key challenges.

From an environmental standpoint, CLT helps reduce the carbon footprint of the structure while relying on a renewable resource. From a construction perspective, it allows for a high level of precision through prefabrication, limiting on-site uncertainties.

Its relevance also extends to interior use. Left exposed, CLT contributes to the spatial atmosphere while supporting natural humidity regulation. This approach reduces the need for additional finishing layers and maintains a direct expression of the material.

A building envelope designed for hygrothermal performance

The building envelope combines bio-based insulation materials: wood fibre and Gramitherm. This pairing offers a balanced approach to thermal insulation, inertia, and moisture management.

Compared to more conventional insulation systems, these materials provide effective thermal lag, helping to reduce overheating during warmer periods. They also contribute to more stable indoor conditions.

A lime-based exterior render completes the system. Its vapor permeability allows the wall assembly to remain breathable, which is consistent with the use of bio-based insulation. This type of construction reduces the risk of internal condensation and supports the long-term durability of the envelope.

Facade detailing: expanded cork and bamboo cladding

The facade design reflects careful consideration of both durability and architectural expression.

Expanded cork, used as an exposed finish in certain areas, provides an effective protective layer.

Naturally resistant to moisture, pests, and aging, it requires no additional treatment or maintenance. Its insulating properties remain stable over time, making it a reliable long-term solution.

Bamboo cladding complements the facade system. As a rapidly renewable material, bamboo offers good dimensional stability and durability in exterior conditions. It contributes to protecting the building envelope while introducing variation in texture and appearance.

Material continuity in the interior

Inside, the material strategy continues in line with the overall approach. Exposed CLT is combined with fermacell® finishes and bamboo flooring. These materials are characterized by low emissions of volatile organic compounds (VOCs), supporting good indoor air quality.

The result is a set of spaces that are straightforward, durable, and coherent, where materials are expressed rather than concealed.

A material-driven approach

This project highlights the value of a considered material strategy. Rather than relying on complex technical systems, it prioritizes simple, compatible construction solutions tailored to actual use.

The combination of CLT, bio-based insulation, and breathable finishes results in a building that performs well while ensuring a high level of comfort for its occupants.

This is the type of approach we support at Natura Mater: identifying materials that are appropriate, compatible, and capable of addressing both environmental challenges and user needs. Architect: Ardism