Lorraine Quast hopes her new house with straw bale insulation encourages people to dream about non-conventional homes in urban areas.
And even though the southwestern Santa Fe-style house, with sun-baked wood and desert colours in Oakville isn’t finished, it’s already attracting attention from people around Ontario.
Quast says they get a constant stream of visitors—architects and people interested in building their own straw bale homes, who have heard about theirs through word of mouth.
“People think we’re hillbillies,” she says. “We’re a curiosity but then when they see us they realize we’re ordinary people.”
The idea for this type of home grew from visits out west, to Arizona . Quast and her husband Michael were enthralled with the colour, light and architecture of authentic western houses, with distressed corbels, posts and clay. This style, combined with their passion for healthy, energy-efficient materials, led to the decision to build a straw bale home.
Set on a mature street a couple of blocks from Lake Ontario, this house will be ready in a couple of months for Lorraine, Michael, and their children Parker, 7, and Mikayla, 5.
“What excites me is that more and more people are coming by and want to do this (build with straw bales),” Quast says.
The house is almost 4,000 square feet, but Quast says, “a lot of that is the 16-inch-wide walls” – a result of the straw bale plus 16 ½ inches of cement/lime plaster on the interior and exterior of the bale. The two-storey home has three large bedrooms and a basement, and although the labour costs were higher, they were offset by less expensive materials. Michael Quast figures it cost about the same to build as a traditional home.
Lorraine says the reaction from neighbours has been mixed.
“It’s an eclectic street, with million dollar homes and little wee cottages. One woman caught me off guard at a Christmas party and told me she hates that we’re imposing an architectural style on the street. I recognize there are issues but I think we’re adding to the spirit of the street.”
Overseeing the job is Mike Holmes, from HGTV’s Holmes on Homes, and a friend of the Quasts. This is his first experience with a straw bale home and he has been surprised at its natural R-value of 40.
Michael Quast, who did extensive research on straw bale homes in order to get building permits and insurance, says the R-value on an average home with two by four inch framing is 12 and the R-value for two by six inch construction is 22.
Mark McInnis, national manager, underwriting for the Canadian Mortgage and Housing Corporation, says R-2000 homes, which are the most energy efficient homes being built today, have an R-value of 40.
(An R-value—or its metric equivalent RSI-value—is a measure of a material’s insulation capability. The higher the R-value, the greater resistance to heat loss, according to CMHC.)
Holmes is also impressed by the straw bale walls’ ability to breathe, which allows for excellent air exchange.
“With a straw bale home you don’t need an HRV (heat recovery ventilator) that R-2000 homes need,” he says. “It’s surprising to see how the house holds cold air in the summer and heat in the winter. This house is a great example of a home built above and beyond the code.”
The straw bale walls and plastering were done by Ben Polley of Harvest Homes in Guelph . Polley, who also lives in a straw bale house, says that the walls gain strength over time because of the addition of carbon dioxide.
“The lime content of the plaster absorbs carbon dioxide over its life cycle,” he says.
He has been building this type of home for six years in Ontario , and turns down a dozen straw bale home requests a year because he can’t get the trained staff he needs.
Polley attributes the increasing interest in straw bale homes to their superior energy efficiency, fire retardancy, cost-effectiveness and freedom from toxins.
“The insulation from straw makes these homes three times better than conventional homes and almost twice as good as an R-2000 home, considered to be the best on the market for energy efficiency,” he says.
As for fire safety, Polley explains that the bales are so dense they don’t have the air needed to catch fire.
“The Canadian Mortgage and Housing Corp. put the straw with the lime plaster in a furnace and blew flames at it,” he says. “The minimum time allowed for the material to resist is half an hour. After two hours at 1,400F, there was no ignition.”
Polley also says that straw and plaster have 10 times the weight carrying capacity of standard two by six framed houses and four times the lateral strength, which protects against wind loads and hurricanes.
As for cost, Polley says that when he’s been bidding for a house against a traditional builder, they’ve been in the same range.
“Straw bale insulation is more labour-intensive as you’re dealing with material not designed for construction, but the straw costs less than conventional insulation.”
“You may spend more on construction, but you’ll save on heating and cooling years down the road,” Holmes says.
Most of Polley’s clients are women, which is unusual in the building industry, and a significant number of them are interested in the health benefits of straw bale insulation. Women contact Polley initially, on behalf of their families, after discovering the benefits of this type of construction.
“The materials are inert,” Polley says. “They don’t off-gas (give off fumes). A large part of my market is families with kids who have asthma.”
Holmes says the pros for building with straw bales are far greater than for traditional materials.
“People don’t know about off-gasses,” he says. “Wood, steel, foam, drywall produce off-gasses. Straw has no off-gasses. And mould likes to feed on the composites of drywall. Straw is resistant to mould, bugs and mice.”
Lorraine Quast points out that straw bales offer no food value for pests like termites, as they’re a waste product from a farmer’s field.
Straw bale insulation is just one of the many new self-sustaining construction methods that Holmes believes will become an important part of the housing industry’s future.
Four years ago, Polley says a study was done that found 1,000 straw bale homes in Canada . There has been no research since then, but Polley says the number of starts has grown exponentially since. He builds eight to 10 straw bale homes a year and is already taking bookings for 2006.
“There’s so much to learn, not just for the builders,” Holmes says. “People will make the change faster than builders. The funniest thing is that it’s not a lot more money to build a self-sustaining home.”
If you’re interested in starting a unique housing project like the Quast’s, Holmes says you should slow down and have patience.
“If you don’t educate yourself on the possibilities, how can you follow up on a builder?
“You should find someone who is using new techniques or wants to learn new techniques. There are not enough builders doing this kind of thing yet, but it’s growing.”
If you’re interested in straw bale construction, you can get in contact with the Ontario Straw Bale Building Coalition through their web site: www.strawbalebuilding.ca. This will also provide you with a list of builders who do this kind of construction.