A Halifax Apartment Built with Hempcrete Walls
Noel Taussig works as a home designer, builder, and renovator in Halifax, Nova Scotia, Canada. When he posted an ad to rent out the new hempcrete apartment unit he built, he got 50 responses in a single day. We can see why so many people were interested in the apartment. This place is beautiful.
Noel built a second suite onto his existing house, creating a duplex. The walls of the addition are made of hempcrete, a remarkable natural building material. It’s a mixture of hemp fibers and lime, with a little water to make it workable. Pounded into forms, it makes a solid wall with a warm, earthy look. It can also be finished with smooth lime plaster.
Hemp is a fast-growing plant that is easy to grow without pesticides. Its fibers are used to make everything from the rope, to clothing, and now walls. Hempcrete is made using ‘hemp chips’, which come from the core of the hemp plant and are a byproduct of the hemp fiber industry. Hemp hits all the high points of sustainability. It’s a renewable natural material that takes little energy to produce. It’s so earth-friendly that if the building is ever demolished, it can just be ground up and spread on a field for fertilizer.
Because of the lime in the mix, hempcrete walls are highly resistant to attack by insects, rodents, dampness, and mold. It’s also breathable – it stops drafty air movements but allows humidity to diffuse out of the house.
Hempcrete is a reasonably effective natural insulator, with an insulating value of R2.5 per inch. These walls are 12 inches thick, reaching R28 and meeting Canada’s Energy Code for Buildings. And it’s continuous insulation, with no thermal bridges to lose heat. To go that extra level and make a Passive House style wall with R40, it can be made thicker or wrapped with another breathable insulation type such as rigid mineral wool boards.
From a sustainability perspective, the most amazing thing about hempcrete is that it hardens and strengthens over time. The lime slowly reacts with carbon dioxide in the air and turns to limestone. Over 50 years, the walls will harden like stone.
" “I say, be brave if you want to try a new sustainable material like hempcrete. Before I tried this, I didn’t know how people would react, but they love this building.” Noel Taussig, Home Builder"
- Hempcrete addition to an existing house, creating a duplex.
- 900 square feet (600 on main floor, 300 in loft)
- Cost: $200,000 (about $220 per square foot)
Why We Love it
- Hempcrete – beautiful and sustainable
- Magnificent special features of stone and wood embedded in the walls
Wayne Groszko is a consultant, researcher, and teacher in Energy Sustainability with 13 years of experience. He has taught at Dalhousie University and the Nova Scotia Community College, in the Faculties of Engineering, Environmental Science, and Energy Sustainability Engineering Technology. Wayne is also President of the Community Energy Cooperative of New Brunswick, and has worked as Renewable Energy Coordinator with the Ecology Action Centre in Nova Scotia. He holds a B.Sc. (Hon.) from the University of Calgary, and a Ph.D. from Dalhousie University.