Building with Hemp


Hemp has a very long association with human history. It was one of the first plants to be spun into usable fibre some 10,000 years ago. Hemp is used to make a variety of things, including rope, textiles, clothing, shoes, food, paper, bioplastics, insulation and biofuel. Also if you mix shredded hemp, with sand and lime it can be used as a material for construction and insulation. Called Hempcrete or Hemplime it is a bio-composite material. A mixture of Hempcrete is easier to work with than traditional lime mixes and it lacks the brittleness of concrete and consequently does not need expansion joints. The result is a lightweight insulating material ideal for most climates as it combines insulation and thermal mass.

Hempcrete has been used in France since the early 1990s to construct non-weight bearing insulating infill walls. Hempcrete does not have the requisite strength for load bearing construction, but with a framework of another material that supports the vertical load it can be used for internal walls. Hempcrete walls are fireproof, transmit humidity, resist mould, and have excellent acoustic performance.

In the UK a new show house has been built to show off the capabilities of hemp. Called ‘Flat House’ it is located on Margent Farm, a 53-acre farming facility in rural Cambridgeshire. Practice Architecture worked alongside hemp farmers to erect this zero carbon home, from pre-fabricated panels in just two days.


Practice Architecture additionally saw the project as a chance to trial using hemp and pre-fabricated building techniques on a large scale. “We have been working with hemp for a while but this is the first project where we have designed and employed a pre-fabricated panel system,”

“Developing an offsite system allowed us to build efficiently, at speed and to build through the colder months of the year – something that can be difficult with standard hemp construction.”


Working off-site with engineers and material specialists, the studio developed large panels made from hempcrete. These were then transported back to the farm and, over the course of just two days, erected to form the structural shell of Flat House. The property was constructed over the footprint of a pre-existing barn.

The project also saw Practice Architecture and Margent Farm develop hemp-fibre tiles, which have been used to clad the house’s external facade. Each tile is bound with sugar-based resin sourced from agricultural waste. “The materials are breathable meaning they regulate the moisture in the air, resisting damp and mould and leading to a healthier environment and air quality.”


A growing number of architects and designers are experimenting with hempcrete in the light of the current climate crisis.

Although cannabis as a drug and industrial hemp both derive from the species Cannabis sativa, Hemp has lower concentrations of tetrahydrocannabinol (THC). The legality of industrial hemp varies widely between countries. Some governments regulate the concentration of THC and permit only hemp that is bred with an especially low THC content.

There is more about the Flat House here.

One thought on “Building with Hemp

  1. just as long as drug growers don’t hide the plants in there & swear you can only trace the house & nothing growing inside the walls.!!


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