In most of Canada, low- and mid-rise apartment buildings are designed like hotels and dormitories: long hallways with units on either side, capped off with staircases at the ends. Once you see it, it’s everywhere; the design forces buildings into the particular shape and dimensions that now fill Canadian cities, and for those living in them, there are consequences, too.

Because the hallway has to connect every unit to two staircases, the typical building design can’t allow for cross breezes, and units with more space are rare.

The layout is baked into provincial housing codes, which require two staircases for fire safety, typically two floors and up. But architects and urban planners stress that buildings can be fire safe with just one staircase: a change that would allow more density and livability, while bringing a host of climate-related benefits. The province of British Columbia is currently exploring the possibility of updating its building code to make them legal.

Most of the world builds multi-family housing with what are called “point access blocks,” explains Michael Eliason, founder of Seattle-based architecture think tank Larch Labs. Instead of building apartments around two staircases (which is the norm in Canada and the United States), compact buildings are constructed with just one staircase. He points to walk-up buildings, rife with character and community, in places like Berlin, Mexico City and Tokyo.

“The way we build housing in the U.S. and in Canada as well, where we typically have at least two stairs, a corridor separating them, and then units on either a little bit of an anomaly,” he explained.

In most of Canada, low- and mid-rise apartment buildings are designed like hotels and dormitories: long hallways with units on either side, capped off with staircases. However, other countries show there is another way: a single set of stairs.

Ditch the second staircase, and receive a host of benefits, explained Eliason, who was commissioned to produce a report on the buildings for the City of Vancouver in 2021. You can build more housing on smaller lots, and the units typically have more light and can accommodate more bedrooms with less square footage. Instead of apartment buildings mostly made up of studios and one-bedrooms, in point access blocks it’s more typical to have three-bedroom units that can accommodate families and other living arrangements.

Cross breezes and embodied carbon

The skinnier single-stair buildings also contribute to climate action and adaptation, Eliason has learned through his work in North America and Germany. He’s especially interested in the intersection of climate and urban planning, and is writing a book on “low-carbon ecodistricts” that also address housing shortages.

Instead of large buildings with apartments that are blocked off from air flow, the layout of point access blocks allow for cross breezes, which are typically reserved for houses.

Cross breezes are an important way for people to stay cool at home as heat waves intensify due to climate change. During the heat dome in 2021, more than 600 people in B.C. died due to extreme heat. New Westminster experienced disproportionate deaths due to extreme heat. Those who died mostly lived in older apartment buildings: in particular, three and four-storey walk-ups with no cross-breeze and no cooling unit.

Another benefit related to climate is that single-stair buildings have less embodied carbon emissions (which are the emissions associated with building materials). He explains that there is a lot of wasted space in typical larger units, which are filled with walk-in closets and other “things you don’t need” because they’re unnecessarily large to fit the dimensions offered by the building plan.

“You have a smaller footprint for an equivalent number of bedrooms...less floor area means less cost, especially if the cost of the two building types is somewhat comparable. It's significantly less embodied carbon,” he explained, stressing that the units should also be more affordable.

“There's less surface area, there's less floor area. All of these things start adding to the embodied carbon of the building.”

Even the pipes make a difference, he said, noting that there is a reduction in the length and number of pipes needed, which also leads to less embodied carbon. About 11 per cent of global emissions come from the embodied sector, which includes the production of building materials such as cement, along with the construction process.

Changing building codes

If B.C. decided to update its building code, it could be following in the footsteps of other North American cities that have pushed back against the double staircase standard. In Seattle, for example, single-stairway buildings are allowed for buildings up to six storeys.

Graphic courtesy of Conrad Speckert

B.C.’s Ministry of Housing says it’s currently “exploring options to enable” one staircase buildings, and it expects to share more information soon.

“We’ve seen research from around the world that has shown single-stair residential buildings can be designed with more opportunities for natural cross-ventilation in apartments,” said Minister of Housing Ravi Kahlon.

“We know the building code needs to evolve to allow for designs that are more climate-friendly and employ passive cooling, and we’re looking to other jurisdictions around the world on how to make that happen here in British Columbia.”

Meanwhile, there is also a push for Canada’s National Building code to allow for single staircase buildings. Architect Conrad Speckert, who developed his graduate thesis at McGill University on point access blocks across the world, submitted a code change request at the national level, which will be prioritized in the next cycle of building code priorities between 2025 and 2030. His thesis found that Canada is the second most restrictive country in the world when it comes to constructing single-staircase buildings, only behind Uganda.

Specifically, he asked the government to update its code to allow for “single exit multi-unit residential buildings of up to six storeys, requiring additional life safety measures and placing limits on the occupant load and number of dwelling units per storey served by the single exit.” Translated, that means allowing for buildings with a single stairway, where instead of two main fire exits there are additional fire suppression systems and limits on the number of people who will need to evacuate all at once.

If it’s nationally accepted, provinces will still need to adopt the code, noted Speckert. However, a handful of chartered cities in Canada – Saint John, Winnipeg, Vancouver, Lloydminster, and Montreal – have the power to municipally implement bylaws that would allow for single staircase buildings.

It’s because of that power that Montreal has more “missing middle” housing than other major cities in Canada: multiplexes, townhouses, and apartment buildings less than five storeys.

An apartment in Montreal's Mile End neighbourhood. Photo courtesy of Alain Rouiller / Flickr

“What Montreal does is they have two very efficiently dimensioned stairs, and you're basically allowed to make them spiral stairs, which, in the national code you're not allowed to have a spiral staircase serve as an exit,” Speckert explained.

However, since it’s a municipal bylaw, “if you're an architect in Montreal, you can use a spiral staircase as an exit for a small building. But if you're in Laval or Brassard, you can't.”

To Speckert, it’s a timely moment for the national building code to take leadership on single staircase buildings in hopes that provinces will adopt the measure. The first building codes were written in the 1940s, and largely based on what American cities such as Chicago were doing at the time: not to prevent fires, but to allow people to escape when fires often occured in timber frame buildings.

Now, fire safety requirements are much different, explained Speckert. Newer buildings have fire alarm systems, fire-rated walls, sprinkler systems, and more.

“These requirements — that come from a time 100 years ago, where the risk level was different — sometimes aren't appropriate today,” Speckert said. “I'm the first person to say that surely larger buildings should have two exit stairs. But, on small, constrained sites, there's a better way to achieve an acceptable level of safety.”

Ultimately, single stair buildings make sense in the present day, which is much different than the time when Canada was first designing its building codes, Eliason agrees: now, Canada doesn't just need more housing, but homes that consider density, affordability, livability, and climate change.

Keep reading

Great article that provides hope both for homeless families and climate-better buildings. One question I had was how "buildings can be fire safe with just one staircase". It took quite a while to find an answer so I thought I'd post it here: several reports indicate that the second exit is by fire truck ladder.

As a retired residential building inspector I agree. Having traveled around the world there are mire options


Setting aside the bemusing, hyperbolic headline, there were a few instances in this article that appear to have some faulty logic.

Cross breeze ventilation is nothing new and I’d suggest is not determined by whether an apartment is served by one or two stairways. The only condition for cross breeze, I believe, is that there is a sufficient air pressure differential between one point of access to the outside and a second point of access (nominally windows or doors). Typically, this pressure difference is realized by wind (and, I hasten to add, there is no pressure difference if the wind is orthogonal to, let’s call it, the axis of ventilation and, therefore no breeze (without assistance)). Thus, building orientation relative to prevailing winds is also important.

Also note that cross-breeze is, in any event, not the be-all and end-all: 35C air is still 35C air, even when moving.



“a change that would allow more density…”
The only density gain by removing a second stairway is due to the floorspace not taken up by a second stairway.

“…and livability…”
If this refers to cross-ventilation, one stairway doesn’t necessarily lead to that result. If it refers to other measures of livability, I don’t think they were mentioned.

“…while bringing a host of climate-related benefits.”
A “host”?

If comparing to European, centre-ville norms, of course you will find a larger percentage of family-accommodating apartments in Europe; those urban districts and the buildings therein were largely designed and built before sprawl and urban flight was a thing. There was (and remains) demand for family-sized units; so, of course it’s more typical to have larger units.
If anyone needs a reminder of the Euro-norm, here’s a Google map link to a specific block in Stockholm where I had the good fortune to live while on secondment for a few months some time ago. Note, also, the “interior courtyards” that are also quite common. I can’t recall if there was more than one staircase in my building but I’m quite sure that not all units had lateral cross-ventilation. There may have been other ventilation devices built-in; don’t know.



(It sems I can't post google maps links... sorry. Just take a gander in Google maps/Earth/Streetview at the city centers of a few major European cities and you'll get the idea.)

Another example in Stockholm of a district, recently re-developed from a sizeable brownfields site, formerly a port.

Another example, of a rowhouse type, BedZED in the UK (watch the video and note one method of ventilation included):

It is obvious, in all these examples, that any notion of sustainability is achieved by intentions going FAR beyond a single building type.

“Another benefit related to climate is that single-stair buildings have less embodied carbon emissions (which are the emissions associated with building materials).”

This is flat-out bollocks and truly throws your reporter’s reputation into question, awards notwithstanding; that said, it’s obviously not solely the fault of the reporter, although I note they have a record of credulous acceptance of what they are told.

In this case, their architect subject is totally misleading. For example, the architect is quoted as saying, “There's less surface area, there's less floor area. All of these things start adding to the embodied carbon of the building.” Absolute crap! Building floor area is a totally different animal than the size of an apartment in the building. If one requires a purpose-built 500 sq m building, sure one can then build a 450 sq m building and say it’s got less embodied carbon; but it’s not a 500 sq m building, is it? If you are going to make meaningful references to embodied carbon, compare based on carbon per sq m, regardless of how many sq m the building is.



Removing one of two stairways doesn’t magically rain rose petals upon the concrete, the spray foam, and anything other construction materials. Nor does adding a stairway to a well-conceived, (near) zero-embodied carbon building diabolically mutate it into a carbon-spewing pariah.

Here’s a terrific video to watch for an introduction to embodied carbon, in the context of choice in heating system, in residential construction. It’s worth watching in its entirety but the core take-away, for me, is from 07m00 to 12m00.

I dislike throwing bricks at reporters, but the topic of urban and building design is so important, particularly because we are starting into whole-city retrofits of R1 zoning, that dodgy reportage, such as this example exhibits, can only set incorrect expectations in the minds of readers without the background to sift out the BS, and cause problems as we densify existing urban areas.

I will say that I generally agree with the last phrase, though I would slightly alter it to read:

“Canada doesn't just need more housing, but homes that consider ecology, livability, and affordability.”


I'll add one more observation that I was reminded of yesterday.

Dwelling construction in hot climates has been going on for a very long time, and there are lessons to be (re)learned from such indigenous architecture.

If you have a WaPo subscription:

If not, you might have WaPo available via your public library. This article's title is: "Ancient elements of Cool", published Dec 28, 2023.

Or, just search more broadly:

Some very intuitive comments, Ken. I think there is some validity in the author's consultations, knowing also that the piece wasn't written by an architect.

The "smaller building footprint" idea is legitimate when you consider that a stair shaft occupies a fairly large piece of land on smaller lots. The greater the vertical distance between floor plates, the longer the stair shaft and its footprint are. Codes require staircases to have breaks with landings every so often to break up long stair climbs, which increase the overall length. The tread width required minimums are also greater in multi-family, multi-storey buildings, often 1.2-1.8 m instead of the standard 0.9 m of single family homes. Ergo a larger footprint. A stair shaft also requires enclosure for fire codes, including self-closing doors with bottom and top landings that accommodate traffic and door swing space, and need to be attached to very solid structural walls. Wall thicknesses add up quickly.

I worked out some basic stair shaft spatial concepts to illustrate this.

For the basic minimum 2.4 m (8 ft) interior floor-ceiling height in a cast concrete or mass timber building with laminated slabs for 15 cm (6") floor plates, the elevational differential between finished floor elevations is 2.6 m (8'-6"). Then: 15 cm (6") stair risers, 1.2 m (4') tread length, 30 cm (12") tread width, a 1.5 m (5') landing at top and bottom, a 90 cm (3') mid-landing, and a 15 cm (6") wall thickness. Total per floor area: 14 m2 (150 ft2), or nearly 100 m2 (1,080 ft2) over seven floor plate levels from the basement to the roof. This excludes parallel hallways, essentially another 1.5 m flat area devoted to circulation. For every foot increase in ceiling height, the staircase floor length increases by two feet.

The area occupied by stairways is one reason why developers don't often take on small lots for multi-family, especially if they are narrow. Getting smaller developers to build on smaller sites is a key issue. Double-loaded vs. single loaded halls and the number and the placement of elevators are also important parts of the calculation. A single-loaded hall / stairway configured to one side allows for larger units on small lots. You cannot run a hallway down the centre of a narrow building without cutting up valuable living space. Eliminating a back staircase and entry could allow an extra unit to the total apartment count, should they have an exterior back wall.

Today it's feasible to replace the concrete above the foundations with mass timber construction, and that goes for modular wall panels built to Passive House standards in climate-controlled factories then trucked to the site and craned, bolted and sealed into place very quickly. Mass timber and PH energy ratings are far, far superior to concrete construction in terms of low carbon and energy specifications. The ratings are even better when these buildings are located in transit-rich walkable neighbourhoods where car ownership and $60,000 underground parking stalls are unnecessary. Essentially, the basement levels only need to accommodate the building's utilities and excess resident storage.

Your links to Stockholm show images of new residential projects not unlike the urban design of Vancouver's Olympic Village. Now, if only housing could explore non-strata concepts.....

Lastly, the CBC did a really interesting piece providing one of the best explanation why so many highrise condos on Canada's big cities are sitting empty. They are too small for average owners!

Stair configuration also plays a role. Scissor stairs are essentially the width of a double hallway and still require a large landing to change directions. Unidirectional stairways require a parallel hallway to access the next level. This doubles the above floor plate areas.

Thanks for your comments, Alex.

I agree that reporters should be consulting experts; in this case, either the reporter didn't understand what was said or the architect was blowing smoke. I have no idea which.

I totally understand that within a building envelope of a specific size, a second set of stairs will reduce the amount of space that could otherwise be used for living area. I don't have a problem with single stairway buildings where it makes sense and is safe; that wasn't what got my eyes rolling.

My primary objection was the clearly stated, but absolutely false, notion that removing a stairway reduces the embodied carbon of a building. The embodied carbon, of a building of a certain size, is a function of the building materials selected and method of construction, nothing more.

If you've not had a look at that video I linked to of Chris Magwood giving a community talk, have a gander; the conclusions he arrived at regarding embodied carbon in residential construction, compared to operational carbon, is eye-opening.

"... the best explanation why so many highrise condos on Canada's big cities are sitting empty. They are too small for average owners!"

I can't agree with that. If a unit is sitting empty, then whoever owns it obviously didn't buy it for it to be occupied. If a condo is unoccupied, in a housing crisis, how can its purpose be anything other than investment? Sure enough, the video confirms they were investment properties.

In the CBC video, Andrew Chang says, "...there's a ton of condos, like this, struggling to sell."

Give me a break. I'd be struggling, as well, to sell an old pair of socks for a thousand bucks. The condo wouldn't be a hard sell if the price was reasonable. For some unknown reasons, there's this received wisdom that whatever price we want to sell something for is "reasonable" and, when it doesn't sell, it's a "struggle".

At 07:43 Andrew compares condo sizes (then and now). then: about 1,000 sq ft. now: about 650 sq ft. Well, look at the two floorplans he shows: the large one (then) was a 2BR; the small one (now) was a 1BR. Apples and oranges. When I rented a 2BR 30 years ago in Ottawa, it was about 900+ sq ft. I have no idea what my 1BR rentals have been over the years, but 500-650 sounds about right.

I have very little sympathy for investors that bought those tiny condos: when interest rates were abnormally low; when they didn't care what they were buying because the value was just going to keep going up and up, right, and tenants would be lined up to pay whatever exorbitant rents were demanded. Of course, gov't policy ought to have provided some guardrails (see my assertion below).

So, now we have, potentially, another bubble, and who knows what might result from that.

Another reason that residential real estate must not be treated as an investment, except for multi-unit rentals and a large percentage of those, preferably, would be publicly owned to keep all rents reasonable over time. Buyers of single-family residences should be buying to occupy. Plain and simple.

In any event, as I mentioned, the sustainability of a place (neighbourhood; city) is determined by much more than simply a building type.


In addituon, there is currently a crackdown by cities and some provinces on short term rentals. Some buildings were purposely designed for AirBnB and VRBO and are full of tiny apartments not much bigger than a hotel room.

You also have the crowd of investor-owners forming a majority on some strata councils specifically to resist the efforts of residents to clamp down on the damage and bad behaviour of short term renters.

BC has recently put short term rentals under the screws, and this has created a glut of tiny condos on the urban market the owners will never occupy to avoid the capital gains tax. Poor darlings.

The building code was initiated to insure a safe exit path in the event of fire. And 2 exits became the North American standard. Change is likely necessary but really it appears the cost savings are exaggerated to me. Do I really believe landlords will lower rent because they have 4 extra suites to amortize their costs? One comment HAH