Frequently Asked Questions

Where are you located?

Northampton, Massachusetts

What is the R-value of hempcrete?

Hempcrete has a conservative R-value of 2. Although its R-value isn't incredibly high, hempcrete is generally used in vapor-open wall assemblies, so it allows the building to naturally self-regulate its relative humidity. In addition to this, hempcrete is really beneficial in that it has lots of thermal mass. It keeps buildings cool, but can also store and release heat as needed!

Can you help me build my home?

Yes indeed! We offer hempcrete and lime plaster installation services for all of New England. For those outside of New England, we are happy to connect you through our Nimble Network to hempcrete and lime plaster servicers in your area. if there are none, we’ll support you in getting interested building professionals up to speed on how to build with hempcrete. Hempcrete and lime plaster act as insulation and finisher, so the rest of the house is up to you and your General Contractor.

Can you teach me to build with hempcrete?

Absolutely! HempStone offers beginning, intermediate, and advanced trainings geared toward building professionals and homeowner enthusiasts who are looking to use natural building materials. We specialize in helping construction crews and design teams learn to specify and use hempcrete, and are willing to travel and train on-site as needed to build networks of hempcrete building professionals across the country.

Where do you source your materials?

Currently, we source our materials from Europe and Canada. Hemp was illegal to cultivate in the US until 2018 and consequently, the industry is in a very nascent stage. However, we think that in the next 2-4 years, there will be a sufficient domestic supply chain and hope to support farmers, processing facilities, builders, and all other involved in the hemp world along the way.

Is it sustainable to source hemp from Europe and Canada?

Hemp just happens to be the best carbon storing biomass solution we have at industrial scale. Because of this, the impacts of adding Lime (a carbon intensive process), harvesting, processing, and transportation do not significantly move the needle away from the carbon benefits. The answer of precisely how much carbon can be stored is measured, primarily in the form of an Environmental Product Declaration (EPD). This is a voluntary certification process, completed by 3rd party, to evaluate the impact of the production and use of a product or material. In the US, EPDs are not established in the hempcrete world, but in Europe, they are a standard practice. Therefore, we can use that data to compare the impact of using one product or the other, particularly when we are importing those materials. An EPD does not include the ecological impact of transportation to the US, but that can be calculated. Cargo shipping is rather efficient, compared to ground shipping. The factoid that sticks in my brain most easily is that it's more efficient to transport things across the Atlantic by boat than it is to go from the East coast west past the Mississippi River, by truck.

I’m from North Carolina and want to build with hemp! What are some resources?

This may be weird for non-North Carolinians, but at least ⅓ of our inquiries come from North Carolina because it is a very exciting place for hempcrete. The state is fortunate to have a robust agricultural hemp community, and North Carolina has some great hempcrete history, with the Push House in Asheville. The designer and builder is still around, though they don't work exclusively on hempcrete nor are very active. The company that provided guidance and material is based out of Chicago.

There's an ecovillage in North Carolina that has been gaining speed. Common Ground has a hempcrete champion named Katy Ansardi. Katy is a member of the US Hemp Building Association, an organization devoted to the promotion of hemp building materials. I encourage you to reach out to the group for local enthusiasm and support.

There's an architect in South Carolina that is focused on natural building, and in particular, rammed earth and hempcrete. April Magill of Root Down Designs held a training with Chris Magwood in 2019. If you don't know about Endeavour Centre, I encourage you to check it out. It's in Canada, but the work that Chris and Jen do there is wonderful and well worth your time.

Can I smoke my hemp house?

No. Hempcrete does not burn.