All things environmental

Musings about the environment and all it touches, from education to city planning

The PassivHaus in my neighbourhood

leave a comment »

img_0533I’ve been watching  a new house emerging in my neighbourhood, near Commercial Drive in Vancouver.  It’s one of many, of course, but this one is special: it’s a full-size duplex built to the PassivHaus standard.

I had to ask to make sure, but in hindsight some of the construction details give it away.  At first it looks like a regular wood construction, with the plywood walls looking ready to get covered in its cladding: stucco, clapboard, whatever.  But the windows seem to protrude out weirdly, and there some tubes and pipes also sticking out strangely.

But a week or so later, the reason is out: an extra thick layer of insulation is added to the outside.  Only then does the outside cladding come on.  This is a house dressed for an arctic winter.

The basic idea behind the PassivHaus design is simple: make the building energy efficient.  In the Canadian context of wood frame houses, that means an extra step after the walls are up.  As in any house, wiring, plumbing, and then  a regular layer of insulation is installed.  This is what we’re used to, it’s fine, except that all the various utilities like wall-mounted electric plugs leak heat like a sieve.  So in a PassivHaus an extra layer of insulation is added to the outer side of the wall.  This really cocoons the house and ensures very little heat escapes (or enters the house during summer heat waves).

To that add high performance windows, and a seal that keeps the outside from infiltrating in.  That seal, of course, would result in very unpleasant, stale air in the house if it weren’t for the third feature of a PassivHaus system: a ventilation system that is coupled with a heat exchanger, warming the outside air before letting it in.

To be under the PassivHaus standard, a building must require less than 15 kilowatt-hours of energy per square meters of floor per year.  In other words, it can be heated by an ordinary hair dryer; that’s about one tenth of an average building.  The extra insulation and heat exchanger cost money, of course; but there’s no need of a furnace, and of course the energy savings add up over the years.

During construction (note the protruding windows, and the insulation on the left wall)

During construction (note the protruding windows, and the insulation on the left wall)

This is not the first one in BC (the first one was a luxury house built in Victoria, and there is a famous one in Whistler).  But it’s the first one I know of that is, well, just a mid-size house meant to fit in a regular neighbourhood, nothing special, not in the news.

I was going to add “meant for regular people”.  But there is no such thing anymore as a free-standing house affordable to regular people, and it’s a shame.  But that’s also an opportunity.

The main factor contributing to the cost of a house in Vancouver is land.  Sure, construction is not cheap, exactly, but it’s still much less than half of the cost of “an ordinary house”, $1.5 million as of this August.  The additional cost of the PassivHaus features is about 10% of the construction costs.  In other words, it is barely noticeable in a crazy market like Vancouver’s.

I would like to see this become a mandatory standard for new construction.  This would create a market for such things as efficient windows (currently imported), and of course more construction jobs.  For those who say that this would put homes out of reach of ordinary people, I answer that we’re already there anyways; speculation has driven this market crazy, and energy efficient features are pretty much a non-issue, specially if costs go down through economies of scale.  On the other hand, “ordinary people” are the very ones for whom a much lower heating bill makes a difference in the long run.

This fits nicely with the recent proposal by the Trudeau government to require so-called net-zero standard for new construction.  I don’t expect the idea to fly; net-zero requires solar collectors and other doodads to make a home an energy producer, and hike up the costs significantly.  Not so with PassivHaus, which I see as a reasonable first step.

It’s ironic that the very first PassivHaus was developed in Canada, back in the 70s in Saskatchewan.  The idea was never followed up here, but it caught the eye of the Germans; if the standard bears a German name, that’s why.  They, the Germans, have a knack for pushing innovation through policies that create markets.  Can’t we?

Advertisements

Written by enviropaul

October 28, 2016 at 4:51 pm

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: