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Writer's pictureKate Hamblet

Hempcrete: A Homeowner's Guide to Sustainable Building

By Kate Hamblet


Photography by Oscar Proctor

Imagine building your dream home with a material that's not only eco-friendly but also provides superior insulation, longevity, and comfort. Enter hempcrete, an amazing building material that’s making waves in sustainable construction. If you've never heard of hempcrete, you're in for a treat. This guide will introduce you to the benefits of using hempcrete for your new home or renovation/addition and why it’s worth considering.


What is Hempcrete?

Hempcrete is a natural building material made from the woody core of the hemp plant (called shiv or hurd) mixed with a lime-based binder. Despite its confusing name, hempcrete is not like concrete because it’s not a load-bearing material. With hempcrete, you still need to have wall framing. Hempcrete is used between the framing and acts as the insulation and substrate. The hempcrete material is then covered with plaster on the interior and exterior wall surfaces, and voila, you’re done. A typical wall assembly has many layers of materials that include plastics and other synthetic materials. A hempcrete wall assembly removes the need for any synthetic materials, so you can have a wall that is entirely natural and healthy. Why Choose Hempcrete for Your Home?


Photography by Hempstone

Eco-Friendly and Sustainable


Renewable Resource: Hemp grows rapidly and requires minimal pesticides and herbicides, making it a sustainable choice.


Carbon Negative: Hemp plants absorb CO2 as they grow, and the lime binder captures more CO2 as it cures, making hempcrete carbon-negative over its lifecycle.


Regional Adaptability: Hemp is a hardy plant and can grow in many climates and soil conditions, making it available regionally, which cuts down on transportation emissions. Its hardiness also makes it a great rotator crop for regenerative farming.


Energy Efficiency and Comfort


Superior Insulation: Hempcrete’s excellent thermal properties keep your home warm in the winter and cool in the summer, reducing energy bills.


Thermal Mass: A hempcrete wall is thick - about 10” depending on your climate. Its thickness helps absorb heat during the day and then release it into your home at night. This keeps your home at a consistent, comfortable temperature without needing mechanical heating or cooling.


Moisture Regulation: Controls moisture in the most amazing way: If you live in a humid climate, this material will make you cry joyfully. It wicks moisture out of the air and moves it to drier air. So if it’s humid inside the house, it’ll pull it out to the outside. It can also store moisture without leading to mold (similar to sheep’s wool).


Healthy Living Environment


Breathable Material: Hempcrete allows moisture to pass through, preventing mold and mildew and contributing to better indoor air quality.


Non-Toxic: Unlike some traditional building materials, hempcrete doesn't release harmful chemicals or toxins, making it a healthier choice for you and your family. It replaces the need for many petroleum-based products.


Durability and Longevity


Pest Resistant: Hempcrete is naturally resistant to pests, including termites.


Fire Resistant: The material is highly fire-resistant, providing an added layer of safety for your home.


Low Maintenance: Hempcrete structures are long-lasting and require minimal maintenance, reducing long-term costs.


How Hempcrete is Used in Home Construction

Hempcrete is essentially an insulation material. You still need floor, wall, and roof framing since it’s not a structural material.


It is most commonly used as wall insulation, but you can use it as floor and roof insulation. However, it tends to be pretty cost-prohibitive for floor and roof insulation, so it’s usually better to use a natural batt or blown-in insulation material (such as wood fiber, sheep’s wool, or hemp batts) for roof and floor insulation.


Hempcrete is amazing for a wall assembly because the entire wall can be made up of natural materials.


In a traditional wall assembly, you have many layers of synthetic materials, starting with the drywall on the interior side of the wall, then a plastic vapor retarder, then some (usually) synthetic insulation between the wall studs, then a chemical-infused plywood substrate, then a petroleum-based house wrap, then a potentially synthetic exterior siding material. In contrast, a hempcrete wall is a hempcrete and plaster. The plaster can be the interior and exterior finish of the wall.


Photography by Hempstone

What to Consider Before Building with Hempcrete


Initial Costs: While hempcrete can be more expensive initially due to limited availability and production scale, the long-term savings on energy and maintenance often offset these costs.


Construction Time: Hempcrete requires a longer curing time compared to traditional concrete, which might extend your building schedule. However, the long-term benefits often outweigh this initial inconvenience.


Availability of Expertise: Since hempcrete is still relatively new in many regions, finding builders and contractors experienced with the material might be a bit more challenging. Look for professionals who have experience with sustainable building practices.


Final Thoughts

Building with hempcrete offers a unique opportunity to create a home that is not only environmentally friendly but also beautiful, comfortable, durable, and healthy. While the initial costs and construction time might be higher, the long-term benefits make it a worthwhile investment. If you’re passionate about sustainability and looking for innovative ways to reduce your environmental footprint, hempcrete could be the perfect material for your new home or addition.




By, Kate Hamblet

The Wellness Architect Balanced Architecture


Kate helps health-conscious families create homes that support and promote health, happiness, and longevity. You'll find her at www.balancedarchitecture.com


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