A building material that has been around for a century is the innovation the construction industry needs to making housing more sustainable, contends Rocksolid Building Products.
The company is working to get autoclaved aerated concrete (AAC) adopted in the Americas. The pre-cast material made of cement, lime, silica sand, and air is widely used in Europe, Asia, and Australia, but it has not yet caught on in North and South America, largely because the industry in this part of the world tends to default to softwood lumber and concrete, said Freeman Willerton, Rocksolid's interim CEO.
"The homeostasis of the industry is what's keeping it the way it is," they told Taproot, noting that traditional materials have been easy to get in Canada — at least until supply-chain squeezes during the pandemic — and tight margins breed a kind of conservatism that makes widespread adoption of new things challenging.
Rocksolid feels it's worth trying to disrupt the consensus view because AAC uses less energy than other building materials through its entire life cycle, from production to demolition (at which point it is recyclable). Its air pockets help to insulate the building, transporting it takes less energy because it is so light, and it goes up easily. All of this makes it the ideal material for building net-zero homes, Willerton said.
Rocksolid currently imports AAC products, but it is aiming to build Canada's first AAC manufacturing facility within three years, with a goal to produce enough material for more than 1,500 net-zero housing units per year.
"Because we have to import it from such a long distance … that does bring up the cost quite a bit right now," Willerton said. "So that's why our production pathway is so important. We're aggressively pursuing that."
In the meantime, there's a lot of work to do to persuade everyone — tradespeople, inspectors, estimators, architects, engineers, etc. — that AAC, sometimes known as aircrete, is a safe and viable product.
"For anything to be adopted, especially at scale, the industry needs to trust it," said Willerton, whose own background is in the trades as an electrician.
Rocksolid has taken a step in that direction by launching Canada's first training course in AAC with Portage College, which operates seven campuses in northeastern Alberta. The micro-credential program includes eight hours of online instruction and onsite labs to give students a chance to work with the material.
Rocksolid Building Materials imports the autoclaved aerated concrete that these houses are made of, but it has plans in the works to build its own manufacturing facility. (Supplied)
The pilot with Portage College is a first step to help Rocksolid develop further training as it works toward building a workforce that is used to AAC.
"It's definitely not everything that someone's going need to be able to confidently build with AAC," they said. "This is the starting point."
Besides being energy-efficient, homes made out of AAC are fire-resistant, and they go up faster, as the material comes in pre-cast panels and beams that are relatively easy to move. Other net-zero building methods are more challenging, which may account for why it is taking longer than expected to build in Blatchford, Willerton posited.
There is growing interest in building affordable housing with 3D printing or hempcrete. In fact, Rocksolid founders Dietmar Schultz and Peter Zuurdeeg met Willerton at a hemp conference. But they came to see the advantages of AAC.
"It's absolutely scaleable. A lot of these new technologies don't have that," Willerton said. "This is 100-year-old technology. So all the kinks are worked out."
That said, getting a new technology like AAC adopted may open the doors to other new building materials, Willerton said.
"This is actually a pathway, not just for bringing AAC into the market, but understanding how a market can change, a market as big as the construction industry."
Willerton believes the construction industry wants to change, but it's hard for any one player to do it alone.
"This has been really difficult to get going," they said. "Everybody's waiting for everybody else in this broken system."
Rocksolid is willing to get the ball rolling on creating the market it wants to sell into, with the support of like-minded businesses around the world.
"If not us, then who?" Willerton said. "And if not now, then when?"