“Passive House takes you back to the fundamental principles of shelter: orientation, seamless enclosure and insulation. Our forebearers utilized these principles instinctively. As technology advanced we began using it to replace smart thinking instead of enhancing it. Passive House does just the opposite and does it in a way that is not only unobtrusive but which promotes a simple, timeless beauty.” – Jarrod Denton, Architect
When it comes to Passive House, I’ll be the first to admit I’ve drank the Kool-Aid.
If you’ve never heard of Germany’s ultra-efficient (oh, how they love efficiency) super-low-energy building standard, have you been under a cold, non-insulated rock?
Basically, to build a Passive House you create a simple house structure, make it really air-tight, wrap it in a ton of insulation and use fans with filters to bring fresh air in and take stale air out. By doing that, you eliminate the need for any major heating or air conditioning systems. A few little heaters here and there in the winter, and windows open in the summer and you’re as comfy as a bug in a rug.
Several cities in Europe have gone so far as to adopt it as their building code, and it’s slowly creeping its way up in popularity here in North America. On one hand people are drawn to it for it’s environmental benefits (no carbon emissions), but I think a huge draw is what I would call a luxurious level of comfort and quiet.
The ultimate test: cold, dark, northern British Columbia
Sure it’s worked well for those moderate-climate folks in Belgium, but how about snowy northern Canada? Well in 2015, construction was completed on the Fort St. John Passive House. It’s a small, northern Canadian town, featuring long, cold winters. What better place to show it off! The house consumes about 90 percent less heating and cooling energy than a typical code-built house because it’s essentially wearing a big, uninterrupted blanket of insulation over top a Goretex-like membrane that keeps air and water out.
The residents pay only $600 a year in utility costs, compared to owners of a typical house that fork out $2,000 more on top of that in annual bills! And money savings aside, think of the simplicity: no furnace to maintain and upgrade, no swings in temperature or noise of fans switching on and off. Just quiet, even-temperature, draft-less, simple living.
A final bonus: since it just uses electricity, the house creates 0.05 tonnes of GHG’s each year – a 99 percent reduction compared to a typical detached single family home.
Yeah that’s great, but it sounds expensive to build.
It is absolutely more expensive off the bat, but cost studies (here’s a one-page summary from Vancouver, Canada) on existing projects have shown a break-even point after only a few years. There’s lots of variables of course, but think about it: you pay way less for energy and you don’t need to install a big furnace or air conditioner.
And remember, the cost to build these has nowhere to go but down. Once builders get a feel for how to do it, they will charge a smaller premium. And the more people that build them, the more local suppliers that will sell Passive House certified components.
But think of all the additional materials needed! Doesn’t that offset the benefits of using less energy?
For the longest time, I thought this was the Achilles heel of Passive House: it takes a lot of energy to make all that extra insulation. However, a University of Michigan study looked at the breakdown of energy for the entirety of a house’s life:
“The primary life cycle energy consumption for [the house] was 15,455 GJ. This is the energy equivalent of burning 2,525 barrels of crude oil. Of this, 6.1% (942 GJ) was consumed in the pre-use phase, 93.7% (14,482 GJ) in the ‘use’ phase, and 0.2% (31 GJ) in the end-of-life phase.
Nearly 94% of the impact of the home occurs when people are simply living there! And of that 94%, the study says the vast majority is from electricity and burning gas. So it’s pretty safe to say that by adding more insulation and thicker windows is a relatively negligible impact compared to the energy savings over the lifespan of the house.
It’s the best form of resilience, especially in places of extreme weather
There are a lot of snazzy ‘smart’ gadgets and green gizmos for homes out there, but in the end, ‘simplicity is the ultimate sophistication.’ A Passive House can ‘weather’ chaotic weather by staying warm on a cold winter night if the power goes out. It is simple, elegant and crazy efficient, so obviously for me it’s a nerdy engineer’s dream. I hope it catches on.