2 Cold Months in a Passive House

The house is not yet complete, but with the colder-than-average winter we’ve been having, I’m sure many of you are curious to know how Kingston Passive House is performing.  The building envelope is mostly complete; the only items missing are the 3 exterior doors.  Even with 2 of those doors being nothing more than 2 sheets of 0.5-inch plywood (The third is a temporary steel door) we have been very impressed with the performance thus far.  Our active heat source is a standard 4800W construction heater.  In terms of passive sources, we have a pair of dehumidifiers running and of course a few CFL bulbs during the day (basement).  We keep the house at 14 degrees; certainly not warm, but a good temperature for working.  Even on the cold days (below -20 Celsius)  The construction heater only runs about a quarter of the time to maintain temperature.  When the sun is shining, the temperature rises in the house – sometimes by as much as 3 degrees!  We have to be realistic here; it will take more energy to maintain 20 degrees, and we’re also not running the HRV yet.  Even when we consider the less-than-adequate doors and absence of inhabitants and other passive heat sources, the consumption will most likely go up a bit.  These early indicators do give us comfort that we’ve done things right; they’re a glimpse into the future, a taste of what’s to come in a super-insulated, air-tight home and it’s really quite exciting.

Using an IR thermometer, we have also measured internal glass temperatures of the tri-pane windows.  With the sun shining, we get readings of 21 – 23 degrees on windows with a hard low-E coating (better solar heat-gain coefficient) and glass temperatures on the shaded side of the house (soft low-E coatings) were about 1.5 degrees cooler than the ambient air temperature.

The house is currently ready for drywall inside, and the metal roofing, soffit and facia arrive this week!  Here are a few pictures showing progress made over the past couple (cold) months:

The OBC doesn't allow Air-Admittance Valves in new construction, so we kept the pipes low in the insulation layer, with a single stack

The OBC doesn’t allow Air-Admittance Valves in new construction, so we kept the pipes low in the insulation layer, with a single stack

Putting the raised-heel to use... Cellulose blown in at 36" deep = R-105!

Putting the raised-heel to use… Cellulose blown in at 36″ deep = R-105!

We tarped (and heated) the exterior in sections to apply the Stucco (EIFS)

We tarped (and heated) the exterior in sections to apply the Stucco (EIFS)

The water-proof layer under the EIFS was a festive RED... Sure got the neighbors talking!

The water-proof layer under the EIFS was a festive RED… Sure got the neighbors talking!

Once the EIFS was complete, the porch roof could be built.

Once the EIFS was complete, the porch roof could be built.