Homeland Hempcrete

On this episode of iHemp Hour, we sat down with Matt from Homeland Hempcrete to explore how prefabricated hempcrete panels are making sustainable building faster, more accessible, and more affordable than ever before.

Hempcrete is a bio-composite building material made from the woody inner core of the hemp plant (called hemp hurd) mixed with a lime-based binder and water.

Unlike traditional concrete, hempcrete is lightweight, breathable, and remarkably sustainable. It’s carbon-negative, meaning it absorbs more CO2 than it produces during manufacturing.

But here’s the challenge most builders face: How do you get clean, consistent hemp hurd for construction?

As Matt explained during our conversation, the US Hemp Building Association (USHBA) is actively working to establish standards for building-grade hemp hurd. The general consensus? As close to zero percent dust as possible, with fiber content at five to ten percent maximum—and no clumps.

“The fiber is what you’d use for textiles, paper, or hemp board. The inner woody core—the hurd—basically looks like wood chips. Cleaned up and sized properly, that’s what goes into hempcrete.”

Here’s exciting news for anyone considering hempcrete construction: Hempcrete was officially approved for inclusion in the U.S. International Residential Code (IRC) as “Appendix BA” in 2024.

This landmark achievement makes it significantly easier for building departments to review and permit hempcrete projects.

The IRC is the basis for residential building codes in most U.S. states and applies to one- and two-family dwellings and townhouses.

This approval recognizes hempcrete as a non-structural wall infill system—similar to straw bale and cob wall construction.

Matt shared that while the USHBA submitted the appendix to help standardize hempcrete building practices, current recommendations focus on single-story construction to simplify the approval process:

“There’s a lot more forgiveness and variability acceptable in a one-story building. We want to make sure you have a well-established process in place for people to follow.”

Traditional hempcrete building—called “cast in place”—is labor-intensive and time-consuming. That’s where Matt’s innovation comes in: prefabricated hempcrete panels that dramatically reduce construction time while maintaining all the benefits of hempcrete building.

Panel Specifications:

• Dimensions: 3 feet wide × 8 feet high
• Thickness: 9.25 inches standard; up to 12 inches for residential (achieving R-24 insulation)
• Weight: Approximately 380 pounds per panel
• R-Value: Approximately R-2 per inch

Why Panels Beat Traditional Methods:

“Even a full-size house with two people—as opposed to five or six—you should be able to put together in less than two days. Probably about a day and a half of assembly.”

1. Superior Thermal Performance

Hempcrete provides excellent insulation against temperature fluctuations, potentially reducing heating and cooling costs significantly.

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But here’s what makes it truly special: thermal mass.

Unlike spray foam insulation (which has a higher R-value on paper), hempcrete stores thermal energy in the wall itself. Solar heat coming through windows gets captured and slowly dissipates, naturally regulating indoor temperature.

“With spray foam, when there’s temperature fluctuations, you’re basically at zero. The only way to change temperature is by controlling the thermostat. With hempcrete and thermal mass, you can capture heat from the sun and slowly dissipate it over time—requiring less energy to maintain indoor climate.”

2. Fire Resistance

Hempcrete is inherently fire-resistant. When finished with lime plaster, hempcrete walls become essentially stone—offering exceptional protection.

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3. Pest Resistance

Bugs and rodents don’t like hempcrete. As Matt noted from his cabin experience: “The lime essentially becomes stone. That’s very protective.”

4. Carbon Sequestration

Hempcrete sequesters carbon, actively offsetting the construction industry’s carbon footprint.

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This makes it one of the most environmentally responsible building materials available.

5. Moisture Regulation

Hempcrete is breathable, contributing to healthier living environments by naturally regulating moisture levels.

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6. Wind and Weather Resistance

The density and weight of hempcrete structures provide natural stability against high winds—particularly important in regions like Michigan and North Dakota.

The cost of hempcrete construction can vary based on climate, wall thickness, and labor availability.

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Current Market Pricing:

For Matt’s prefabricated panel system, a 530-square-foot exterior wall envelope runs approximately $15,000-$18,000—competitive with cast-in-place hempcrete while offering significant labor and time savings.

The Long-Term Value Proposition

While hempcrete may cost 10-12% more upfront than traditional construction, the performance benefits create a crossover point where ownership becomes cheaper:

“You’re going to pay initially 10% more for a hempcrete house. But the performance you have every single month, year over year—it’s going to perform better and require less energy to maintain. My estimate is five years or less before hempcrete becomes the cheaper option.”

Exterior Finishes:

• Lime plaster (recommended): Provides air-tightness, fire protection, and pest resistance while maintaining breathability
• Siding: More affordable but doesn’t offer the same performance benefits

Why Lime Plaster Is Ideal:

“Hempcrete is not airtight—it’s a super-aerated infill material with lots of micro pockets of air. You need some kind of air barrier without affecting permeability. Lime plaster is perfect because it blocks wind and is fully fireproof.”

Interior Considerations:

The panel system includes studs on both sides, allowing for:

• Standard hanging of kitchen cabinets
• Any siding choice on the exterior
• Easy electrical routing (channel with a router, install conduit, cover with lath and plaster)

One challenge Matt highlighted—and one that resonates strongly here in Michigan—is the lack of hemp processing infrastructure in many states.

Currently, Matt sources hemp hurd from:

• Kansas
• Minnesota
• Montana (hopefully soon)
• North Dakota (the goal for the most regionalized supply)

His vision? Every state should have one or more processors for their own material.

For those interested in starting processing operations, Matt mentioned two equipment options:

• Formation Ag (Colorado) – relatively affordable decorticator equipment
• Ag Processing (Montana) – unique system that can accept CBD-type stocks, processing differently than traditional methods

Estimated equipment costs range from under $500,000 for scalable equipment to over $1 million for complex systems with established reputation and minimum output requirements.

While hempcrete is now recognized in the IRC, local building officials may still need education about the material. Matt’s experience in Fargo, North Dakota, offers a roadmap:

“It takes extra time because almost all building officials haven’t seen or come across hempcrete. But once they understand it and see what it’s already done successfully within the bounds you’re setting for your project, they’re usually pretty receptive.”

Timeline: Expect approximately six weeks of back-and-forth documentation for initial approvals.

The USHBA is leading several critical initiatives:

1. Standardized testing protocols for hempcrete performance
2. Comparative testing projects to quantify energy savings versus traditional construction
3. ASTM testing standards for hemp hurd quality

Matt is personally leading a comparative testing project launching this spring—building two identical 300-square-foot structures 15 feet apart: one traditional construction, one hempcrete with lime finish. Long-term analysis will help quantify exactly when hempcrete becomes the more economical choice.

Contact Homeland Hempcrete: Visit homelandhempcrete.com for inquiries about custom hempcrete panel projects. Matt works with clients to adapt existing house plans to the panel system, typically requiring only minor modifications to match preset panel sizes.

Join iHemp Michigan: Stay informed about hemp building developments in Michigan, upcoming hempcrete workshops, and advocacy efforts to develop local processing infrastructure. Membership is just $100/year at iHempMichigan.com.

Key Takeaways

✅ Hempcrete is now IRC-approved for residential construction in most U.S. states

✅ Prefabricated panels reduce construction time from weeks to days

✅ 10-12% higher upfront cost pays back within approximately 5 years through energy savings

✅ Thermal mass advantage means better real-world performance than R-value alone suggests

✅ Fire, pest, and moisture resistant with lime plaster finish

✅ Carbon-negative construction actively fights climate change