Among Allin’s case studies are The Triangle, a housing project designed by Glenn Howells Architects in the UK town of Swindon that features timber frame units filled with poured hemp concrete, and Case di Luce in Bisceglie, Italy. , an apartment building designed and built by Pedone Studio and Pedone Work in which hemp was used in the plaster and precast blocks.
Hempcrete was first launched in France in the 1990s, but construction certification issues and stringent agricultural licensing requirements have hampered progress. However, as the climate crisis deepens, the urgency to find positive design solutions for the planet is driving architects to experiment. At Margent Farm, a hemp farm in the UK county of Cambridgeshire, Practice Architecture used hemp harvested from the surrounding fields to build a house for the owner and his family in 2019. Flat House was built using panels precast timber planed and engineered I – joists, with hempcrete infill carried out at HG Matthews’s Brickworks in South Buckinghamshire.
Last year, Practice Architecture’s sister company Material Cultures teamed up with Studio Abroad to build a 968-square-foot timber-framed house in Somerset called Block House. Made from locally sourced wood, hempcrete blocks and wood fiber insulation, the house sits on flint foundations designed to have minimal impact on the environment. Often, hempcrete is hidden from view by heavy lime plasters, but architects have chosen to express hemp textures inside buildings, integrating them clearly into the material palette.
“Hempcrete is versatile, beautiful and breathes moisture,” says George Massoud, director of Material Cultures and Studio Abroad. “Essentially, it’s also natural and speaks to a future where we could cultivate all the materials we work and build with.”
Elsewhere in Cambridgeshire, Jonathan Tuckey Design last year received planning permission for Hempcrete House, a contemporary extension to a Victorian villa in a conservation area, and more recently a new home built from hemp blocks on top of a hill in Surrey, which is currently Under construction. Hempcrete is not certified as load bearing, which means it requires a structural system made from a material such as wood, but Jonathan Tuckey Design made it a virtue in the design of the Surrey house. “We leave the wooden beams exposed, in a nod to some Arts & Crafts country houses,” says project architect Rob Leechmere.
The practice was drawn to hemp concrete because of its carbon capture qualities, insulating value, thermal mass and breathability. “It requires a change of mindset from the traditional building science of wrapping buildings in membranes,” adds Leechmere. “You have to understand that this is a type of construction that facilitates the movement of moisture.”
In America, the use of hempcrete in architecture has been held back by bureaucracy, but the United States Hemp Building Association submitted hempcrete insulation for certification in building codes earlier this year. Companies such as HempBlock USA and Hempitecture already supply hempcrete products, and researchers at Texas A&M University are working on a plan to 3D print new “resilient buildings” using the biocomposite, exploring its potential to increase the availability of affordable housing while reducing its environmental impact. .
The cultivation of industrial hemp is legal in 47 US states, so we can expect to see a new crop of hempcrete buildings sprout in the years to come.