Despite all the fuss about on detached housing in Ã¼ber cold climates, there have been several projects recently that seemingly disprove the fussers.
Now, that’s not to say that meeting the Passivhaus standard in certain localities is a walk in the park – it’s certainly difficult in many places, like Siberia; the north slope of a steep, east-west valley (GraubÃ¼nden!); Fairbanks… That being said, there are projects (certified, even) that meet the Passivhaus standard in climates north of 7,000 heating degree days (HDDs) – and with the advent of something like – well, much of that nonsense could become completely moot.
In the next year, I’m certain we’ll see several more projects that disprove the cost-ineffectiveness of meeting 15 kWh per square meter in cold climates. It is definitely something that merits debate – but hey, it’s not like anyone’s been , or anything…
Chris Corson’s Maine Passivhaus
The first project is the house that Chris Corson (the owner of ) recently wrapped up in Knox, Maine. The project has seen some good press (including a GBA story) and great praise recently – I ran into many people at the recent Passivhaus conference in Hannover, Germany, discussing it, including some Canadians and Germans.
The 1,600-square-foot two-bedroom house sports a treated floor area of 1,140 square feet (106 m²), which some would say falls under the “small” category. It also happens to be a detached home in a really cold climate (modeled at 7,345 HDDs). Chris was able to bring the cost of construction to under $130/sf.
The modeling bests the specific space heating demand, coming in at 3.11 kBTU/ft²a (9.82 kWh/m²a). This was done through a combination of superinsulation, phenomenal windows (from Intus) and a phenomenally low blower door test of 0.286 ach50.
The most impressive bit about getting the space heating demand so low, outside of achieving affordability in a difficult climate, was leaving wiggle room for future additions or modifications. Furthermore, cost savings may have been realized by dialing back the insulation closer to 4.75 kBtu/ft²a.
G•O Logic’s red house
The second project is G•O Logic’s 1,500-square-foot, three-bedroom Passivhaus in Belfast, Maine – just down the road from the project above (by the way… WTF is up with Maine?!?).
This one also garnered , and recently snagged a LEED for Homes Project of the Year award. Yup, they were able to garner PH and LEED Platinum certifications for ~$160/sf. You can read up more on the project at .
The NewenHouse Passivhaus in Wisconsin
The third project throwing a wrench in the ever-weakening argument is the Ã¼ber-compact NewenHouse in Viroqua, Wisconsin (7,795 HDDs), with Carly Coulson as the certified Passive House designer. This tiny (968-square-foot) kit house has a treated floor area of 888 square feet (82.5 m²).
This project sports local windows and Cardinal triple-pane glass, while the doors are Energate. Like the Knox, Maine, Passivhaus, the NewenHouse is wrapped in a jacket of cellulose – and similarly comes in well under the specific space heating demand.
Carly recently presented the project at the Hannover Passivhaus conference. Here are some of the project specs:
- Space heating demand: 11.4 kWh/m²a (3.61 kBTU/ft²a)
- Primary energy demand: 104 kWh/m²a (32.9 kBTU/ft²a)
- Blower door: 0.51 ach50
- Wall U-factor: 0.09 W/m²K (R-63)
- Slab U-factor: 0.10 W/m²K (R-57)
- Roof U-factor: 0.06 W/m²K (R-94)
The project is also rocking a solar domestic hot water system (Velux) that is expected to provide nearly two-thirds of the domestic hot water needs, and a PV system for site net zero energy.
The project went through , for Passivhaus certification, is Energy Star certified, and is expected to hit LEED for Homes Platinum.
Total cost for NewenHouse – including solar DHW, PV, and accessory structures – is a whopping $173/sf. If there was a LEED Titanium, this Ã¼ber-tiny Passivhaus in an “extreme” environment would surely qualify.
While these may not be the – these are sound, extremely cost-effective houses and further proof that there is more of a in extremely cold climates – rather than a detached housing one. And if locally made PH windows and glass ever become available, that cost-effectiveness will only improve.
If you haven’t yet signed the to protect the Passivhaus standard in North America, then mosey on down and drop your digital signature.
Mike Eliason is a designer at in Seattle, Washington.