Rare Forms Aims to Create Healthier Homes

Sustainable by Design

President Greg Bossie

Greg Bossie jokes that negative ideas around building with straw starts in childhood.

“We all grew up with the Three Little Pigs,” he said. “So people have a lot of misconceptions about the viability of straw as a building component.”

But no one’s huffing, puffing, and blowing houses down that are constructed or renovated by Rare Forms, a unique, mission-driven construction company that Bossie launched in 2020.

At the heart of the business model are what’s known as seed straw panels, which are assembled to form the exterior of a house or business.

“I really felt that I wanted to push further into a values- and mission-based structure, particularly around the use of bio-based building materials and internal structure.”

“We build a wood frame, so they are structural. We build it in a steel jig table, and then the straw gets compressed with a pneumatic press,” he explained. “So there’s no binder, there’s no lime or cement or anything like that in it. It’s just compressed straw, which performs really well in terms of the comfort and insulation of a structure.”

And straw is not hay, he added, knocking down another one of those misconceptions. “Straw is just the woody stalk of the grain plant, which could be wheat, rye, oat, rice, any grain that has a woody stalk. We use rye from Plainville Farm in Hadley.”

He explained that the hard, compressed straw, wrapped in a sealed panel, has the same base molecular structure as wood, and is not prone to decomposition, partly because of the way it’s airtight, yet ‘vapor-open,’ allowing any water entering the structure to exit quickly, preventing moisture damage.

The straw panels are also fire-resistant, whereas foam insulation is flammable, he added.

“Lots of people worry about fire, justifiably. But compressed straw, when compressed in a panel, behaves like timber, which means that, when exposed to fire, it chars on the outside and protects its inner core. With a straw panel, we can get a one- or two-hour fire rating, so it’s actually far less fire-prone than, say, any fluffy insulation that allows air movement, because you need oxygen movement to fuel fire, and when you’ve got this incredibly compressed structure that doesn’t allow any air movement through it, it’s really fire-resistant.

“Straw-based building systems have been used for millennia,” Bossie noted. “But actually encasing straw — compressing straw into a wood frame and panelizing it in this way — is really an innovation of the last maybe 12 years or so. It’s a combination of two well-worn building technologies — wood frame and straw bale building combined into one system.

Compressed straw panels, like those in this home under construction, are both structural and insulating.

“That allows us to utilize the advantages of off-site construction methodology, meaning that we can do all of this in a climate-controlled environment,” he went on, while walking BusinessWest through the shop where bales of hay are stacked, ready to be compressed and panelized.

“One of the risks of traditional straw bale building, particularly in our climate, is that, during construction, it can be exposed to a lot of moisture. Straw panels allow us to work in a controlled environment,” he noted. “We can compress the straw into these wood panels, wrap those panels in weather-resistant barriers, and then install them on site in a relatively short period of time, so that we can limit any potential water exposure during that time. Roof panels tend to take a little bit longer than wall panels, but we can basically assemble this high-performance envelope very quickly.”

Building a Passion

Bossie went to school for architecture and worked in that field for a number of years, but when he moved to Massachusetts from California in 2011, he ended up co-owning a company called Stone Soup Concrete, which specializes in concrete countertops. Later, he was project manager for a design-build company working in the residential sector.

“That got me into building science and high-performance building. But I really felt that I wanted to push further into a values- and mission-based structure, particularly around the use of bio-based building materials and internal structure.”

That idea became Rare Forms, which was just Bossie at first, actually doing the construction before the company started to grow; it now totals about a dozen employees.

“Operational carbon is really important; it adds up over the lifetime of a building. But all of that embodied carbon happens now.”

“We were doing residential design-build, primarily retrofit and addition work to start, and then got into doing some new construction homes,” he explained. “And then, a year and a half ago, we actively pushed into the straw panel aspect of things, which had been my goal for quite a while.

“Straw panels allow us to build homes and additions that actually store more embodied carbon than they emit in the construction process,” he went on. “The construction industry has been focused on what we call operational carbon for a long time, which is energy usage — and trying to reduce our energy usage — and we’ve made incredible strides with that over the last 30 years or so.

Greg Bossie says his company’s values extend to environmental impact, homeowner health, community support, and more..

“But in the last 10 years — really, the last five to seven years — people started to seriously look at embodied carbon and realize that, in the current state of climate crisis, operational carbon is really important; it adds up over the lifetime of a building. But all of that embodied carbon happens now. And lots of buildings get built in such a way that they have an incredibly high embodied carbon footprint.”

What Rare Forms does, Bossie explained, is use bio-based building materials to substantially reduce or even invert the embodied carbon aspect of building, while also maintaining high building performance and the low energy usage. Another motivation is better indoor air quality, meaning greater comfort and health for building occupants.

“There’s a lot of asthma issues that are caused by building materials from all the foams, so we’re trying to build with completely foam-free assemblies wherever possible, which, in new construction is very achievable; with retrofits, it can be a little bit more difficult with older structures.”

While the straw to create the wall panels is sourced from Hadley, the company’s roof panels are insulated with a product called TimberHP, a wood fiber insulation product manufactured in Madison, Maine, from waste timber from that state’s sprawling timber industry.

In short, “we think about sustainability pretty holistically,” Bossie told BusinessWest. “There’s the materials side of things, which is choosing what you build the house out of. There’s also the waste management, doing as much selective deconstruction as possible, meaning saving fixtures, finishes, any building materials you can, keeping as much out of the landfill to begin with as possible, either saving materials for use in the project or donating those materials.”

Meanwhile, the company works with local sawyers to source timber locally, and also strives to reduce transportation emissions. For example, while Rare Forms mainly works in the 413, it’s currently working on a project in Peru, Vt., and has come up with a way to lessen travel impact on the environment.

“Our team meets here at the shop, and they carpool in one vehicle up there. They stay overnight during the week and then drive back so that we don’t have a team of four people each taking individual vehicles two hours each way every day,” he explained. “Trucking building materials is an incredibly high emissions aspect of building.”

Mission Driven

The seed panel system was designed by New Frameworks in Essex Junction, Vt., one of three founding member companies — Rare Forms and Building Integrity in Columbia, Mo. are the others — in the Seed Collaborative, a partnership that aims to create a broad network of companies using local materials to build carbon-positive systems.

“The function of buildings is to provide shelter for people. Ultimately, I think that how we relate to other human beings is what defines our lives. How we take care of each other is what defines the value of a society. How we shelter people defines our culture of care.”

“We share the methodology of manufacturing straw panels, as well as other shared services — we’re sharing marketing services and business consulting services, and trying to consolidate a lot of the infrastructure of each individual business to make this endeavor more accessible from a business perspective, and also to help make the kits and panels themselves more affordable, so these homes can be more accessible to middle-class homeowners,” Bossie explained, adding that the Seed Collaborative will continue to expand across the U.S., starting with the next set of partners in Colorado, Maryland, and Washington.

Rare Forms has also carved out a niche in prefabricated accessory dwelling units (ADUs), tiny homes that blend efficiency, sustainability, and aesthetics. The company recently won an award in an ADU design competition staged by the North Adams Partnership and AARP.

Greg Bossie says Rare Forms essentially combines two well-worn building technologies, wood frame and straw bale building, in innovative new ways.

“The state is really inclined to push ADU expansion right now; it’s one way that we can increase housing density and available housing units,” he noted. “We have a housing affordability and availability crisis, and ADUs are one way that we can increase housing density in existing neighborhoods without substantially impacting the character of those neighborhoods.

“It is, unfortunately, a really expensive way to do that,” he admitted. “The cost per housing unit for ADUs is high because you’re taking essentially all of the infrastructure that you need for a 1,500- or 3,000-square-foot house and compacting it into, say, a 600- or 900-square-foot house. You’ve still got all the utilities, all the electricity, all your mechanicals and plumbing and kitchen and bath. So the cost per square foot for an ADU tends to be substantially higher than for a larger house. But we’re working hard to find ways to make them accessible to middle-class homeowners.”

The company’s values extend beyond building materials and environmental impact; they include work in the community as well. Rare Forms donates 1% of all its revenue each year to nonprofit organizations, including the Hitchcock Center for the Environment, the Connecticut River Valley Conservancy, Leave No Trace, the Venture Out Project, and Community Involved in Sustaining Agriculture.

“We focus on both donating monetarily to local organizations and also using our space to help build communities,” he noted, which includes hosting events focused on everything from building science to promoting women and people of color in the trades.

From a broader perspective, “it’s about people,” Bossie said. “The function of buildings is to provide shelter for people. Ultimately, I think that how we relate to other human beings is what defines our lives. How we take care of each other is what defines the value of a society. How we shelter people defines our culture of care.

“And I wanted to — both personally and from a business perspective — really invest in building something that can care for people, both in terms of what we build and how we build it and how we build the business as well, making sure that we are investing all of our resources back into the people that are here, employees of Rare Forms, but also our trade partners, our clients.”

So when Bossie calls Rare Forms a mission- and values-based business, he’s got a lot on his mind.

“I like people,” he said. “I also have three daughters, and, while I don’t spend a lot of time thinking about legacy, the way that I want to define the success of my own life is — like a lot of people, I think — can I leave the world a little bit better for my kids than I found it?”