Low-carbon.
Breathes like
a living wall.
Hempcrete is not a new material. It has been used in construction across Europe for three decades. Wales has the crop, the lime geology, and the construction sector to become a leader in it. What it has lacked is the domestic supply chain to make it viable at scale.
Beth yw e · What It Is
Hemp hurd.
Lime binder.
Water.
Hempcrete is a composite of hemp hurd (the woody inner core of the hemp stalk) mixed with a lime-based binder and water. The mixture is cast into moulds or sprayed onto a structural frame to form walls, floors, and roof insulation.
It is not a structural material in the load-bearing sense. It requires a timber or steel frame. But as an infill and insulation material it performs strongly against conventional alternatives on thermal comfort, vapour permeability, acoustic performance, and embodied carbon.
The lime binder continues to absorb CO₂ as it cures, so hempcrete walls become more carbon-negative over time, not less. A well-built hempcrete wall will continue sequestering carbon for decades after construction is complete.
Perfformiad · Performance
Low embodied carbon
The hemp stores carbon absorbed during growth and the lime binder reabsorbs CO2 as it cures, giving hemp-lime walls a very low, and potentially negative, lifecycle carbon footprint depending on the binder and build.
Breathable Wall
Vapour-permeable construction regulates internal humidity naturally, reducing condensation and eliminating the need for mechanical ventilation in many applications.
50-Year Lifespan
Hempcrete walls harden and strengthen over time as the lime binder carbonates. Buildings constructed in France in the 1990s show no material degradation.
No Cement
Lime binder replaces Portland cement entirely. Cement production accounts for approximately 8% of global CO₂ emissions. Hempcrete eliminates that input from the wall build.
Local Material
Grown and processed in Wales. Lime is abundant in Welsh geology. The material supply chain can be almost entirely domestic, which keeps embodied transport emissions low.
Hygrothermal buffering
Hemp-lime moderates both temperature and humidity, smoothing internal conditions and reducing heating and cooling demand.
Enghraifft · Precedent
A proven method.
Wales next.
Hemp-lime construction is not experimental. Hempcrete and structural hemp-block systems have been used to build homes and commercial buildings across Europe and North America, and the methods are well established. What Wales has lacked is not the material science but the domestic supply chain to make building with hemp viable at scale. That is the gap Hemp Cymru is working to close, so that hemp grown in Wales can be processed in Wales and built into Welsh homes.