Hempcrete is a bio-composite made from hemp hurds (the woody core of the hemp stalk), a lime-based binder and water. It is a non-structural material, used as insulating infill around a structural frame. BIOMATERRA supplies low-carbon and high-performance building materials: hemp hurds and lime binders, wood fibre and hemp insulation, plasters and finishes, and membranes, tapes and sealing accessories.

Plants absorb carbon as they grow, and that carbon stays stored in the material, which can substantially lower a building’s embodied carbon. Bio-sourced materials are also vapour-open and hygroscopic: they buffer indoor humidity and help wall assemblies dry. Many have low VOC emissions, which each product’s data sheet documents.

It depends on the material. Manufactured products such as insulation and membranes come with test reports or evaluations used to show code compliance. Hempcrete is not yet referenced in the National Building Code, so it is generally permitted as an alternative solution, which usually requires documentation from a professional and acceptance by the local building authority. We can supply technical documentation and connect you with professionals who have done this before.

Material costs are typically higher, and the difference varies by product. Part of the premium can be offset by energy savings and, in some assemblies, by fewer layers. We keep our pricing as accessible as possible and offer discounts for projects with a social, community or affordable housing dimension.

Hempcrete has been used in buildings in France since the late 1980s, and wood fibre insulation has been used in Europe for decades. The lime binder in hempcrete continues to carbonate and harden over time. As with any wall, durability depends on design: the assembly must be protected from prolonged wetting and finished with vapour-open materials.

Building with these materials differs from conventional construction and benefits from experience, but it is accessible. We provide resources and guidance for self-builders. We can also connect you with licensed partner contractors for a full build, work alongside you in a hands-on learning approach, or organize a workshop build open to volunteers and community members.

Wood fibre and hemp insulation provide roughly R-3.5 to R-4 per inch, comparable to mineral wool and cellulose. Hempcrete is closer to R-2 per inch, so hempcrete walls are built thicker. These materials also store more heat than light synthetic insulation, which slows summer heat gain, and they can absorb and release moisture when the assembly is designed to dry.