Patrick Sisson at reports on the ground breaking (no pun intended) work of  two Vancouver locals~Joseph Dahmen, a professor of architecture at the University of British Columbia, and mathematician Jens von Bergmann of MountainMath Software. They’ve developed the “teardown index” by determining the ratio of land to home value. Relative Building Value, or RBV needs to be 60 to 70% for a new residence “but when the RBV drops below 10 percent, the chances for a teardown increase dramatically.”. 

How dramatically? Based upon their formula, the researches estimate that 25% of the current single residential houses in the city could be gone in the next twelve years.

Due to skyrocketing home prices, half of all single-family homes in Vancouver currently have an RBV of below 7.5 per percent, and research showed that roughly a quarter of all single-family homes sales were tied to teardowns. Absent any zoning changes or dramatic shifts in the Vancouver housing market, the tool predicts that roughly 25 percent of the detached homes in the city will be torn down by 2030.

To Dahmen, these findings suggest the city needs to have a serious conversation about zoning and density.“Do we want very limited numbers of units for a certain number of rich people?” he says. “With another million expected to move to Vancouver in the next 20 years, what do we do? This is an example of why zoning needs to catch up with radical changes. Vancouver needs to understand what the city is, not what it was.”

With the index being applied to the “RS” or single family housing zones of the city, the two researchers postulate that these zones contain 68,000 houses and that 40 per cent of the heritage stock has been demolished since 1985. Allowing for multi-family housing in the RS zones would “tip” the teardown index as the profit from several units on a lot would raise its relative value and increase density. And that means thinking about the single family housing zones in a novel, but not unique way.

As Dahmen states “To create the kind of multi-unit, low-rise housing that you see in Berlin, Paris, or Montreal would require letting go of the kind of single-family home that’s sacrosanct in North America.”

Of course there are also environmental cost savings to producing more density on the same lot, and utilizing renovation instead of demolition to produce more units would be favoured.   You can take a look at Jens von Bergmann’s interactive map of single family house teardowns here.


Images: The Tyee and Vancouver Real Estate Podcast


  1. How about relative building value vis a vis proximity to Skytrain? Look at Brentwood or Joyce/Collingwood vs Nanaimo Station or 29th. Why do the former have towers and the latter single detached?

    1. When I asked Gordon Price that same question, he said the local residents have successfully resisted density. It’s shocking that we have SFH that you can spit to from a Skytrain station that has been around for decades.

      In the same conversation, I asked him if row housing had ever been proposed in Vancouver. He said the city floated the idea in Marpole and the residents were looking for a rope and a tree. I would love to move from my house into a fee simple row house, less land value more money in the structure, but the days of doing that affordably have of course long gone.

      1. The Renfrew/Collingwood vision is based on a survey sent out in 2003. That’s a long time ago. Even then, approval for new housing types in a random survey fell short of approval by just .7%. The general survey received majority support.

  2. 25% tear down in 12 years sounds like a big number until you remember that those houses are mainly on the older end of the spectrum — pre-1960s and in many cases pre-second world war. Those houses are already 60-80 years old and there is very little economic life left in them, not to mention that very few people want to live with the inconveniences of homes that old. I find it more useful to look at it as a function of total turnover, in which 25% in 12 years equals about 2% per year, which means a 50 year or so turnover of the whole single family stock. Not unexpected in wood frame houses in areas where affluence has been rising dramatically.

  3. Our house is 2.2% of the value of our property. Yikes.
    But it’s not going anywhere. It’s a simple straight gable vernacular, but whoever built it before WW1 included a huge bay window – a real one that includes the floor – not the erzatz plug-ins in rough openings you see today. Makes a huge difference – it creates space and diagonal views – which increases the perception of space. Yet no one is building them.
    It also has a foyer. You can keep your idiotic granite counters and dreadful open concepts. Give me a foyer – and a separate kitchen. How people can stand to live in a house where the kitchen and living room are one? It’s awful.
    And the lowest part of the house is a foot above grade. Basement flooding is impossible. I suspect that the future will bring a leaky basement crisis.
    Vancouver’s building stock is being torn down because it is built so crappy – design and execution.

    1. Blame Vancouver’s zoning bylaws for the lack of proper bay windows. The truncated ones are not the choice of designers or builders. They’re harder to build. But you’d have to set the entire facade back by the projection of the bay for it to be allowed. You have to give up real space for the perception of space.

      1. Oddly enough, the bay in our house is in the side yard – which is over 7’ wide. It gives a real sense of spaciousness – not cheek by jowl with the neighbour. The view is to the mountains in the NE. How someone planned this out back in 1912 is a mystery – and it’s 9’ wide. That’s huge for a house this size. It had a covered porch that was filled in, as were so many, who knows when, in the interest of a bigger interior.
        Insofar as setting the facade back to allow the projection, can’t you get the same overall footage? I like the cantilever acting as a rain cover over the entry
        Re. bays being harder to build – I’m no carpenter, but watching a Larry Haun DVD on framing – boom boom, no sweat. Fast. Bays with built-in seating – so useful.
        The best book I’ve read on perceived vs actual space is architect Duo Dickinson’s first: Small Houses – really a delightful read.

        1. Well, good framers are pretty fast – even with tricky assemblies. But it’s still easier to cantilever the floor and plunk the the bay on top of that. And if you want storage in the seat you have to do it that way.

          Back in the 90’s Vancouver planners reigned in allowable building depth (bigger back yards) among other strategies to curtail “monster houses”. The result is that a house built to it’s permissible floor area almost completely fills the allowable envelope for width, depth and height. It’s often a challenge to get enough articulation in the facades.

          Meanwhile we’re working on an addition and restoration of an older house and opening up the closed-in veranda as part of the package. That will be a big improvement to the streetscape.

  4. On the positive side, new houses in Vancouver probably need half the energy to heat and will withstand much stronger earthquakes. The building envelopes (and therefore the likely life of the building) are also improving by the week. We’ve learned a lot since the days when you kept a house from rotting by blowing hot air right out the walls.

  5. The article is talking about 1 million new comers to the Greater Vancouver area over 20 years while quoting the number of RS zoned lots in Vancouver itself (68,000). Just making a clarification.

  6. Why the aribitrary decision to limit new homes to a height of 29.5 feet above grade. Seems that allowing for a height increase would greatly alleviate the shorting of housing and allow for folks to stay in single family homes rather than tearing them all down and building townhomes that lack the sense of privacy that one can enjoy in a single family home.

  7. Trying to make sense of the Renfrew/Collingwood Plan – based on a survey that was given out way back in 2003. I understand the general survey part, but not the random survey part. That doesn’t have much in the way of numbers attached to it. It reads that the ‘agree to new types of housing outnumbered the disagree part by almost two to one’, but that it falls .7% short of outright approval. ?
    This needs to be revisited. Joyce/Collingwood, 5 min away, is densifying at warp speed – including a new building by Henriquez – while the areas around 29th and Nanaimo Stations are positively bucolic. It makes no sense. There should be tens of thousands of people living here.

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