The Dumont House

The first time I saw Rob Dumont’s house I was unimpressed. I was visiting an ex-girlfriend in Saskatoon, I mentioned that I was doing some research into sustainable homes, and she said “there’s one near here, we should walk by it.”

It just looked like any other house. The Dumont house is in the colonial revival style, it’s simply built and doesn’t stand out in the neighbourhood, which has a suburban feel to it (though it’s not far from the downtown). I’m used to seeing half million dollar ecohomes, so when you take away the architect and expensive finishes, solariums, thermal mass walls, radiant floors, etc., it’s hardly recognizable as an ecohouse. I arranged to go back later and visit Rob Dumont, who gave me a tour of his home and some other projects he was working on. What initially turned me off about the Dumont House (because it challenged my preconceptions) now makes it one of my favourite sustainable homes.

16 inch double wallWhen Dumont built this house in 1992 it was one of the world’s most highly insulated homes – but the house, like Dumont himself, is understated. Dumont took the double wall system from the Saskatchewan Conservation House, stretched it out to a full 16 inch wall cavity, and filled this space with blown-in cellulose insulation (which is just recycled newspaper with borax added for fire proofing and pest control). There are about 16,000 lbs of cellulose in the house – but what makes this insulation system really special is that the two walls have very little framing between them, so there are far fewer pathways to lose heat through the wall, either through leakage where the insulation doesn’t meet the wood perfectly, or by ‘thermal bridging’ through the wood itself. It may seem obvious, but it needs to be said: wood is way worse insulation than insulation is. A 2×6 stud wall with R20 insulation batts has an overall insulation value of about R13. Rob Dumont’s walls are R60, the attic is R80, and the windows are R5. The whole house is carefully air sealed. It takes less than 1/4 of the energy to heat Dumont’s house that it would for a conventional house. In 2000 Dumont wrote an article describing the energy efficiency features of his home.

Hot water heat-exchangerAs we continued the house tour, Rob showed me some things that really could be added to any existing house. The first was a drain water heat exchanger, just a copper tube wrapped around the shower drain – as hot shower water comes down the drain pipe the cold incoming water in the coil is warmed. “On a shower it will recover about half of the heat that’s otherwise going down the drain,” said Dumont. He quipped that “I’m worried that with the price of copper, in a home invasion someone will steal it.” Still, barring home invasions, the economic payback is pretty quick – if your hot water heater is electric the heat exchanger will pay itself off in 5 or 6 years, with gas maybe double that. Next we looked at the hot water heater itself, which is a standard tank but wrapped with batt insulation and a thermal blanket adding up to about R28.“Without the insulation it loses about 100 watts of heat continuously,” Dumont said, “with the insulation it’s down to about 25 watts.”

Painting of the house by Phil

Because of the simplicity of the Dumont house, it wasn’t expensive to build. The insulation, upgraded windows, and a solar thermal heating system, added about 7% to the building cost. “If I’d put brick on the outside of the house instead of hardboard siding,” said Dumont, “the brick would have cost more than all of the energy conservation features. I’d much rather have an energy-efficient house than a brick house.” In fact, the energy efficiency finished paying for itself in 2008, after 16 years – now it’s turning a profit. And he pointed out other non-monetary benefits – no draftiness, no cold feet, and the nice aesthetic of the deep window ledges.

Rob Dumont, like many of the builders and designers I’ve met, started his work in the 1970’s, and spent some time wandering metaphorically alone in the desert in the 80’s and 90’s. “Society has got a very short attention span,” he said, “there are waves of interest, but mother nature bats last. I started working in the 70’s on the Saskatchewan Conservation House, one had to really keep the faith through a part of the time since, because not many people were very interested. I must admit back in 1973, with the oil shock, I thought the reasonable thing to do would be to change the way we do our houses radically. That was my youthful naivety at the time.” He showed me a book of solar homes that was written in the late 1970’s, a sort of hippie version of what I’m trying to do, and I realized that I’m just the latest emissary of societal interest, something Dumont has seen come and go. I feel like this time it may be different, but I’m not sure. “It’s encouraging,” said Dumont, but “it’s not nearly at the level I’d like it to be. EF Schumacher put it nicely, he said the wind may not always blow but at least we should have our sails up. That’s the way I feel.”

Rob and his wife Phil took me to see a college basketball game, in which the home team, the Huskies, thoroughly trounced the competition (both women’s and men’s teams). I pictured Rob in his younger days playing basketball, fit and idealistic, believing he could change the world. And he did – it just changes very slowly. I wonder, when I look back in another twenty or thirty years, how I will remember this time. As the beginning of real change, or as lost opportunity? All I know is that my visit with Rob Dumont left me more optimistic than when I arrived.

One comment

  1. Hans Eich says:

    Great post. I’d be really interested in the details of the wall make-up on this house. Is there poly under the drywall? Did he seal the outlets (or did he even keep all the mechanicals and electricals to the inside walls only)? If there have been any air leakages into the insulation, has there been damage over the years?

    Anyways. Great to see that someone actually figured out that the increase of energy efficiency on this house, was a smaller influencer than design changes (i.e.: the brick).

    I hope, I’ll be one of the ones, doing a good job at carrying on the torch of good high efficiency home building now.

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