Project CARBON Advances Scalable Biobased Insulation For Housing Renovation
The Netherlands faces the challenge of improving the energy performance of 2.5 million homes. Although biobased insulation materials are technically suitable for this task, their use in renovation remains limited. The CARBON research project by TNO aims to overcome practical and commercial barriers by developing affordable, reliable and scalable insulation solutions for floors, façades and roofs.
Removing Barriers To Biobased Insulation
Materials such as cellulose from recycled cardboard, biopolymers, hemp and straw offer effective thermal insulation while reducing dependence on fossil-based and energy-intensive alternatives. They may also store biogenic carbon during their service life and provide new markets for agricultural and secondary raw materials.
However, building owners, housing associations, contractors and installers still lack sufficient long-term performance data to confidently specify these materials or provide guarantees. Questions remain around moisture behaviour, ventilation, fire safety, installation methods and durability under real-life conditions.
Running from 2025 to 2027, CARBON brings together TNO and 14 partners from across the Dutch renovation supply chain. The consortium combines expertise in material research, product development, architecture, prefabrication and installation.
Testing Materials Under Practical Conditions
The project will investigate how biobased insulation performs over time and under varying environmental conditions. Researchers will measure the effects of moisture, ventilation and installation techniques on thermal performance. They will also assess fire safety, building physics, environmental impact, costs and the requirements needed to support warranties.
The research covers a broad range of renovation methods, including internal insulation systems, cavity-wall insulation, blown-in roof insulation and prefabricated elements. Demonstration projects will help translate laboratory findings into practical design and installation guidelines.
Among the solutions being developed are renovation roofs insulated with hemp, biobased systems for flat and pitched roofs, cavity-wall insulation, underfloor insulation for crawl spaces and digitally measured prefab systems for renovating buildings from the inside. The consortium is also working to optimise cellulose insulation production to further reduce its environmental cost indicator.
Building Confidence Through Demonstration
CARBON is expected to deliver insulation applications that are technically, economically and practically feasible at scale. By providing verified performance data and clear guidance for design, specification and installation, the project could increase confidence among architects, contractors, suppliers, housing associations and property owners.
Although the primary focus is existing housing, the findings may also support the wider adoption of biobased insulation in new construction. In this way, CARBON could contribute to lower-carbon renovation while accelerating the transition towards a more circular, biobased construction sector.
Source: TNO
Photo: iStraw