Hemp in construction: a natural, insulating alternative

Hemp is revolutionizing the way we build our homes. Eco-friendly, insulating, and full of common sense, it is returning to the forefront as a natural ally for responsible housing. Let's find out more about it together!

Things to remember

• Hemp is an effective eco-friendly insulator, ideal for thermal and acoustic regulation.
• Its derivatives, such as hempcrete, offer healthier and more sustainable construction.
• This plant is breathing new life into a local, circular industry, from the field to the construction site.

Hemp-based materials

Hempcrete (or "chanvroc") is a mixture of hemp shives (the woody part of the stem), natural lime, and water. This material offers a unique combination of properties: it is insulating, breathable, moisture-regulating, and durable.

Unlike conventional concrete, it does not crack under temperature variations and allows the building to "breathe."

Hemp isn't limited to concrete. It can be found in several construction products, such as:

• plant fiber-based coatings for interior walls;
• thermo-acoustic insulation panels;
• eco-friendly mortars for breathable masonry;
• blown insulation for attics or floors.

These solutions replace mineral wool or polystyrene, which are often derived from fossil resources and are not very recyclable.

The advantages of hemp as insulation

Remarkable thermal comfort

The porous structure of hemp allows it to store and release heat slowly, which stabilizes the indoor temperature. Thus, it provides coolness in summer and gentle warmth in winter.

A 30 cm wall made of hempcrete has a thermal resistance comparable to that of conventional insulation materials, but with the added benefit of natural moisture regulation.

An ally of silence

Hemp fibers also absorb noise. By insulating the walls and floor to ceiling with hemp panels, you gain significant acoustic comfort.

A house that breathes

Hempcrete acts as a natural humidity regulator, absorbing moisture when the air is too humid and releasing it when it is too dry. This breathing process prevents mold growth and improves indoor air quality.

A sustainable and circular material

Hemp grows quickly (in about four months) and requires no pesticides or intensive irrigation. It can be cultivated in most regions of France and Europe. Using hemp in construction supports short supply chains and the local economy.

In addition, the entire plant can be used: the long fibers, because hemp is making a comeback in textiles, the seeds for food or cosmetics, and the hemp shives for construction.

Hemp-based materials have a negative carbon footprint throughout their entire life cycle, from cultivation to demolition. And when the building reaches the end of its life, hemp concrete is 100% recyclable or compostable.

Ultimately, a hemp house is not just a place to live: it is a concrete gesture for the climate.

Hemp on construction sites: how is it going?

Building with hemp requires real expertise. Hempcrete, for example, is sprayed or poured into formwork around a wooden frame. It takes longer to dry than conventional concrete, but the result is incomparable: a breathable, insulating, and naturally regulating wall. More and more craftsmen are training in these techniques, and the industry is rapidly taking shape in Europe.

In Ireland, several public buildings have already taken the plunge. Schools, passive houses, eco-neighborhoods, etc. Some houses built entirely from hempcrete boast exceptional energy performance (up to 70% savings on heating).

And architects are increasingly interested in it for its texture, raw aesthetics, and authenticity.

A sector with a promising future

The renaissance of hemp in construction is only just beginning. Between technical innovations, new ecological standards, and collective awareness, the industry is already attracting investors, as well as architects and craftsmen.