Vermont Architect Builds First Permitted Hempcrete Structure in Denver

Photo Credit: John Hames
Heady Vermont Staff 11 Dec 2017

DORSET, Vt. — Vermont Architect Bob Escher certainly didn’t set out to become a cannabis pioneer and on the surface, the buttoned up, straight-laced, “Baby Boomer” appears closer to financial planner than Phish fan. However, Bob Escher does have a radical cannabis agenda: pragmatism.

In an exclusive and comprehensive interview, Escher talked to Heady Vermont about literally stripping down the cannabis plant to its woody core in the form of industrial hemp, and how his discovery, design, and building process in Denver, highlight both the potential for hemp as a sustainable building material, and how he overcame the misconceptions and obstacles that come with the legal status of industrial hemp in the United States.

What the reader won’t find is any association between Escher personally or professionally with hemp’s well known first cousin marijuana. All the more interesting, this is an interview strictly about industrial hemp and how an open minded professional Architect has been impacted by a cannabis epiphany inspired by his “Millennial” son and how his all-star team made hemp history by building the first permitted Hempcrete structure in Colorado’s capital.

Heady Vermont (HVT): Tell us a little bit about your background and how you were first introduced to the idea of hemp as a building material?

Bob Escher (BE): I’ve been an architect for 25 years and lived in Dorset since 1987. My practice is around 90% residential work and 10% commercial. I also work out of state and am licensed in NY, NJ, VA, and CO soon.

A little over a year ago my son Alex told me that we should explore expanding my practice using hemp as a building material. His presentation convinced me that not only was hemp an incredibly diverse plant, it was also a market that was going to open up in the US as the laws for growing were changing.

We went out to Denver and Boulder, studied the laws, attended some conventions, met some people, and then we started making some phone calls.

HVT: I know from meeting that you didn’t strike me as the ‘hippy’ type and that Dorset isn’t exactly a commune community, so did you personally have any reservations about getting involved with cannabis?

BE: I’m involved in the industrial hemp industry in order to develop a new building type and design within my architectural practice. In order to accomplish this goal, I need to educate my clients that hemp has nothing to do with marijuana and that it has been used as a building material for centuries throughout the world.

Left Hand Hempcrete workshop flier, image courtesy of Bob Escher, AIA

HVT: I know that you’re working with a group called Left Hand Hemp out in Colorado, so when you guys got connected up out there in Colorado, what were the steps?

BE: Alex and I met the two principals of Left Hand Hemp, Kelly Thornton and Alli Cloyd at the NOCO Hemp Expo convention back in April. They teach classes on how to build with Hempcrete so we figured the best way to learn, was to sign up for a class, get our hands dirty and build something!

When I called Kelly, he said that his next class would be in October for hemp entrepreneur named Eric McKee who wanted to build a 16 foot by 20 foot post and beam Hempcrete barn for himself in the suburbs of Denver…and he was looking for an architect!

Eric’s goal was to use his workshop to develop materials for the ski industry using hemp technology and bioplastics.

HVT: Let’s talk about Hempcrete 101 – the basic concept of Hempcrete and what it really is as a building material.

Finished Hempcrete, consisting of shredded hemp hurds, lime, and water – image courtesy of Floyd Sutton

BE: Hempcrete is made from the material in the core of the stalk, called the hurd. After it’s been processed, it basically looks like shredded wood chips, but when you mix it with a lime binder and water it becomes Hempcrete.

Once the mix is complete, the Hempcrete walls are created by packing it between removable forms very much like what you see in concrete foundation wall construction. Basically, the Hempcrete is the insulation in the walls and once it has cured, it will give you an R-value rating WAY beyond anything you can get with standard insulation materials. At this point, the only thing you can’t build with Hempcrete is the foundation and slab.

Hempcrete insulation packed into forms surrounding the post and beam frame of the building – image courtesy of Floyd Sutton


HVT: So, no slabs and no foundation, those are the only limitations pretty much?

BE: At this point, yes.

Interior view of completed Hempcrete walls between the post and beam frame” – image courtesy Floyd Sutton
“Exterior view of completed Hempcrete walls between the post and beam frame” – image courtesy of Floyd Sutton

HVT: You mentioned an “R-Value Rating” before, which I think is some sort of the efficiency rating right? I’ve also read that Hempcrete is fireproof, mold-proof, and pest-resistant?

BE: The R-value is a measure of how an insulating material resists the flow of heat. The higher the number, the better the insulation value.The fire rating is the measure of time it takes a material to catch on fire. Typical ratings are 30 minutes, one hour, etc…

Hempcrete is fireproof, it’s mold-proof, it’s pest resistant and is carbon-negative, meaning it absorbs carbon in the atmosphere. It also absorbs the impurities in the ground and then releases nutrients back into the soil. Every part of the hemp plant can be used in products ranging from medicines to electronics

HVT: Can you give us a sense of the scale of this project and the neighborhood in the suburbs of Denver.

BE:The Hempcrete workshop is a 16 foot x 20 foot post and beam barn and it’s located in the back yard of a home in suburban Denver. It’s a thriving neighborhood of young families and professionals that was built in the 1930s and 40s, in the shadow of the old Stapleton Airport. All the houses have private fenced in backyards.

HVT: So how did your building become the first permitted Hempcrete structure in Denver?

BE: We didn’t realize this was going to be first permitted Hempcrete structure in Denver until we went down to City Hall and applied for the building permit.

When I told the zoning officer the building was made of Hempcrete, she said, ‘what’s that?”. I said, “it’s hemp mixed with lime and water and it’s a building material.” She said, “you mean like pot?”

We realized at that point that our project was not only going to be the first hempcrete structure in Denver, but it was also going to introduce a building material that was associated with a rural environment (out in the desert or up on a mesa) and bringing it into a suburban and urban neighborhood.

The Denver zoning officer also realized that this was something new and sustainable, so we were bounced upstairs and worked directly with one of the city’s supervisors who was just as excited as we were to introduce this product to their city.

One of the issues we ran into during the permitting process was the “fireproofing”. The location where Eric wanted to put his workshop was in an area that the zoning required a ‘Underwriters Laboratories (UL)’ fire-rating of ‘one hour’. Knowing that Hempcrete is totally fireproof, we didn’t think it would be a problem. The zoning supervisor agreed, but because it is a new building material, he required we provide certification that our building conformed.

After many hours of research, I could not find any ‘UL’ listing stating that Hempcrete has a rating of a half-hour, one hour or two hours! There’s data in Europe, there’s data in Canada, but in the United States, the certification process hasn’t been done yet.

Luckily, by shifting our building 18” to get it out of the 1 hour rated zone, we were able to get our building permit.

This issue identified how important it is for Hempcrete to conform with National Standards. The criteria to build an “out-building” is a lot less restrictive than building a house, and as an architect, I need to be able to tell a client that their house is built up to the standards of the US Building Industry.

The US is now in the process of certifying Hempcrete so we should have an official ‘UL’ listed fire rating and insulation ‘R’ rating in the near future. Everywhere else in the world that builds with Hempcrete has had these certifications for years.

HVT: What kind of resources did you have as far as education in learning about Hempcrete yourselves, but also educating people like the zoning board about Hempcrete?

BE: There are a lot of great books out there plus the Internet is full of information and videos. However, the best way to educate the public and state officials is to build a Hempcrete structure, put it out there on social media and invite them to come out see it!

HVT: One of the themes that I noticed with your process was the technology and the fact that this was a multigenerational project with you and your son.

Father and Son team, Architect Bob Escher and son, Alex – image courtesy Bob Escher

BE: It’s a wonderful collaboration using my years of experience as an architect and combining it with Alex’s entrepreneurial knowledge and experience with multimedia and social media tools. Alex started a blog on Hempcrete starting back in August and he’s already gotten over 100,000 hits! It blows me away how social media can get things out there and make it so easy to share information.

HVT: Where is the project at now and what has the reaction been?

BE: We started the design in the beginning of May and applied for the building permit in July. Eric hired Mark Cover from Forbes Road Sawmill & Woodworks to fabricate the post and beam frame and together with master carpenter Onefree Foster and Eric, they built the workshop structure so it was ready for Left Hand Hemp and Eric to have their Hempcrete class in late October.

We had the most amazing diverse group of people attend the class and we owe a great deal of thanks to the core of probably eight or ten people who were there every day! Overall, there was maybe 200 people that came to help or observe the process. It was absolutely amazing.

Left Hand Hemp workshop attendees mixing hemp hurds, lime, and water in Fall 2017 – image courtesy of Floyd Sutton

The Practical Challenges of Building With Hemp in Late 2017

HVT: So where did you source the hemp to produce 16’ x 20’ building?

BE: This is where the sustainability factor was challenged by political reality. We ended up getting the hemp from overseas, because we wanted the highest quality material to build the workshop, and at the time, this was the best source.

The problem is that in the U.S. there is a limited amount of hemp being grown and there are only a few companies that can provide the services to process the raw hemp. I can’t tell you how many people I talked to in Colorado who said they have a crop of harvested hemp that is just sitting in their barn because they can’t process it to get it to the market. That’s what’s got to change – and luckily it is changing.

HVT: This seems like the kind of project that can change that and show people that here’s a kind of tangible, understandable, universal, nonpolitical example of what this plant can do – it can also do all these other things and it’s carbon-negative and if the language from certain regulations was changed in a few different ways, everybody could do this on an industrial scale.

Interior view of completed Hempcrete walls between the post and beam frame” – image courtesy Floyd Sutton

HVT: So your interest is presumably in the hurd inside the stalk, right? Is there variability in the cellulose from one strain to another or other differences?

BE: There are many strains of the hemp plant. The strain we use for Hempcrete is totally different from the strain that is grown for food, medicinal purposes, or bio-plastics!

HVT: I think it’s really exciting as far as the sustainability and that’s where hemp seems almost too good to be true in some of the things you hear about: hemp fuel, and hemp building materials that are carbon negative and fire-proof, pest-proof, and even mold-proof.

Not only that, but up here in the northeast where we’re from, it’s all about energy efficiency and reducing the use of heat and electricity, and this is the ultimate efficient building material.


HVT: So, I want to end by asking about your future goals with Hempcrete, more structures in the suburbs, something in the northeast, or something different? Where do you go from here?

BE: Right now, I have three other Hempcrete projects in the works, two in Colorado and one in Vermont. Our post and beam workshop out in Denver happened because Eric had the foresight to know that building his workshop would garner an enormous amount of interest and could then be used as a vehicle for educating the public about the benefits of hemp.

My goal is education, not only for the common person, but also for the government regulators and building industry officials so they can get on board to not only change the laws allowing our farms to grow hemp legally, but also to certify the many products that can be produced from this amazing plant.

It’s also important that the Hempcrete structures we build are of the highest quality design and made from the best building materials. When you look at the workshop that we built in Denver, it is a simple post and beam structure that showcases the aesthetics and utility of the Hempcrete walls and ceiling. Just wait until it’s finished!

HVT: So, if you build it, they will come?

BE: Exactly. It’s getting people to see it and touch it.

HVT: We have brain-drain to Maine and Massachusetts and out of everything, we as Vermonters can’t be losing cannabis people to Massachusetts!

BE: My son Alex is a good example of growing up in Vermont and leaving the state once he was done with college to find work. He came back because he saw an opportunity to build a business in a budding industry! Vermont needs to create the environment where young entrepreneurial people his age can explore new ideas and build businesses.

HVT: This is really such a cool project and so “cutting-edge” that we love getting to learn about it and I think that people will look back at this in the future and maybe say that Hempcrete was a turning point in thinking more seriously about sustainability and maybe take the knowledge that’s been around for centuries with this plant.

BE: Whoever thought a plant that has been grown around the world for centuries would be “cutting edge”! Once it’s harvested, it’s uses are unlimited!

HVT: And that you yourself come from a relatively conservative background in terms of cannabis and what has historically been the cannabis culture. It’s the fact that this is a plant that’s so multi-faceted it could connect you and your son across the generations. As well as link together, people interested in horticulture and agriculture, building, design, all of these things — this to me is the perfect story to looking about and thinking about this plant in a different way.

HVT: So where is the project at as of right now in early December?

BE: As of last week, the windows and doors have been installed. Mark, Onefree and Eric are working on the interior and exterior details to get the workshop finished by the end of the year.

Progress photo of the Hempcrete workshop as of December 2017, complete with chairlift swing for extra style points… – image courtesy of Floyd Sutton

HVT: What’s the best way for people to follow what you’re doing and your friends and partners in Colorado and Vermont?

BE: If you go to my website at your first impression will be…this guy does Hempcrete design??? What you will see is my portfolio of custom homes, country clubs, libraries and apartments I’ve done throughout the country. I have added a new “Hemp” section to my website that showcases the Denver workshop and will highlight my future Hempcrete designs.

Both Left Hand Hemp at and our post and beam contractor, Mark Cover at have excellent websites and Facebook pages.

Here in Vermont the best source of hemp information is The Vermont Hemp Company at and of course, Heady Vermont!

HVT: It’s funny you mention not being a stereotypical hemp guy, maybe this project will be your gateway to dreadlocks and Phish tour!

BE: I think it’s too late for me to consider dreadlocks but I will be happy to join you at the next Phish concert in the Heady Vermont front row box seats!

HVT: Whether it’s with the CBD or building materials or nutraceuticals, it seems like every acre of hemp that replaces an acre of corn is better for the planet. It’s a very cool time to be alive, thank you again for your time and for sharing this. I hope we can look back on this in the future and be happy that we’ve moved forward and laugh that it took us so long.

BE: Let’s talk again, because it’s going to be changing every month…

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