ZNE from scratch? Renovation or demolition? The question gets tougher every day

Lloyd AlterlloydalterOctober 28, 2019, Treehugger

Evening shot of house
© Byrn Davison/ Lanefab

Sometimes we have to decide between “neighborhood character” or carbon emissions and density. A new Passive House in Vancouver is a good example.

For years, this TreeHugger has been a proponent of preservation and renovation rather than demolition and replacement. But over the years I have renovated my own house twice, added a bit of insulation here and there but not enough to make a serious difference, because I wanted to retain that historic character of the wood and the windows. In the process I have probably spent as much money as I would have had I knocked it down and replaced it, and I have now “locked-in” fossil fuel consumption and carbon emissions, even though I pay a premium for “green” Bullfrog power and gas.

38 E 37th in vancouver

© Byrn Davison/ LanefabI started thinking about this when I got a bit of a jolt, seeing the tweet from Bryn Davidson of Lanefab, who showed a photo of the “asbestos laden fossil fuel hog” he demolished to build a new Passive House in Vancouver. It’s not that different from the house I live in, even down to the coincidental 38, my street number too.

Rear of house

© Byrn Davison/ Lanefab

The new house is 2,800 square feet, including a basement suite, so it is now multiple units instead of one. It has a flat roof, which Bryn says is a virtue, especially as we look at increasing residential density. (I still worry about leaks.)

Bryn Davidson @Lanefab@Lanefab

Roof deck at the #E37thPassiveHouse

As we move from single family homes to duplexes and four plexes it becomes more and more important that we use the roof for outdoor space (or solar / green roof).

This is why we shouldn’t require gable roofs on every new house or duplex.

View image on Twitter

9812:11 PM – Oct 26, 2019 · Vancouver, British ColumbiaTwitter Ads info and privacy22 people are talking about this

The walls are 17 inches thick and what seems like an insane R58 for the Vancouver climate, with Passive House certified windows, so this is going to be comfortable inside, no matter what the weather throws at it.

Wide open interior is lovely

© Byrn Davison/ Lanefab

It’s got a big Zehnder ComfoAir Heat Recovery Ventilator, so there will be a lot of fresh air, even when it is all sealed up in the hottest or coldest days.

Living room

© byrn Davison/ Lanefab

Every room is full of light and openness, a real graphic response to those who say Passive House makes this difficult. In fact, it has a lot more window and light than my 100-year-old house.

Windows over kitchen counters

© Byrn Davison/ Lanefab

There are even clerestory windows over the kitchen cabinets, which almost seems like an excessive luxury in a Passive House design.

Interior toward kitchen

© Byrn Davison/ Lanefab

The demolished 38 in Vancouver looks like it was in a lot worse shape than my 38, and I only had tiny bits of asbestos. Passive House barely existed when I did my first renovation, and their EnerPhit renovation standard came along years later. I didn’t know the extent of the climate crisis either. My more recent renovation involved subdividing the house into two units and doing a high performance addition, but I suspect that if I was starting the whole process today, I might have thought differently about renovation vs building new.

Windows are nice and warm

© Byrn Davison/ Lanefab

“Locked-in” emissions are going to become the question of our time when we design buildings. We have to build them now to a standard that will be acceptable in 30 years because the building will still be around. Doing that in a renovation is really expensive and challenging.

cat on stairs

© Byrn Davison/ Lanefab

I keep saying, “The greenest building is the one already standing,” but if we want a world of zero emissions, along with increased density and affordable housing, we might have to give up a bit of that “neighbourhood character” or other similar excuses that are often used to prevent new housing from being built, and learn from Byrn.