Repost: Why single-stair design is important

BC has updated its building code

Last Thursday, BC updated its building code to allow single-stair apartment buildings up to six storeys, which has been legal in Seattle since 1977. This means that small apartment buildings no longer need to use a hotel-style layout with a long hallway connecting two stairwells. Instead they can have a smaller footprint and more livable apartments around a central stairwell, as is common in Europe.

• Twitter thread by Brendan Dawe. “Just to remind everyone, the thing that makes single-stair apartments a good idea is that it facilitates better laid out apartments on smaller lots.”

• Twitter thread by Ravi Kahlon, announcing the change.

• Videos by Uytae Lee on single-stair design and fire safety.

• Single egress stair building designs: policy and technical options report. By Robert Heikkila of Jensen Hughes. Daily Hive story by Kenneth Chan.

The following post, explaining why single-stair design is important, is from December 7, 2023.

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Twitter

The Ontario housing task force recommendations in January 2022 included the following:

Modernize the Building Code and other policies to remove any barriers to affordable construction and to ensure meaningful implementation (e.g., allow single-staircase construction for up to four storeys, allow single egress, etc.).

The National Housing Accord proposal in August 2023 included a recommendation for changes to the National Building Code to allow and encourage more affordable projects which require less labour (improved productivity):

These can include modular housing construction, mass timber and single egress for multi-unit residential buildings up to six storeys.

The BC government announced yesterday that it was considering allowing single-staircase designs for low-rise apartment buildings:

Over the next year, the Province will lead a discussion on enabling single-egress stairs in the BC Building Code.

Why is this important?

Right now in BC, any low-rise apartment building ends up with a hotel-style layout: a long hallway with apartments on either side. The hallway takes up a lot of space, so to spread the cost over a larger area, the building has to be bigger.

The hotel-style layout also results in narrow "bowling alley" apartments. Adding another bedroom means adding a lot of space between window and hallway, so 2BR and 3BR apartments are expensive.

In Europe (and in Montreal), it's common to see low-rise apartment buildings with a single central staircase. This makes it possible to build livable apartments on a small site.

Apartments don't have to be as narrow. You can have windows on multiple sides of the apartment, providing cooling via a cross-draft. You can have bedrooms away from the street.

Single-stair designs are common in Europe and in Montreal (Montreal provides a second exit via an external staircase). Seattle has allowed them since 1977.

With single-stair design, fire-resistant construction and sprinklers are important. From Seattle’s building code:

(7) Not more than 5 stories of Group R-2 occupancy are permitted to be served by a single exit under the following conditions:

(7.1) The building has not more than six stories above grade plane.

(7.2) The building does not contain a boarding house.

(7.3) There shall be no more than four dwelling units on any floor.

(7.4) The building shall be of not less than one hour fire-resistive construction and shall also be equipped throughout with an automatic sprinkler system in accordance with subsection 903.3.1.1. Residential-type sprinklers shall be used in all habitable spaces in each dwelling unit.

Conrad Speckert has a detailed proposal for a change to Canada’s National Building Code.

He points out that there's a number of fire safety measures, like sprinkler systems and fire-resistant materials, that didn't exist when building codes were first being developed 100 years ago, and that European countries (which don't require two exits for a small apartment building, like Canada and the US do) have a good fire-safety record.

He’s also posted photos of the European apartment building where he grew up:

Mike Eliason has been trying to persuade state and local governments to allow single-stair designs for a long time. A report that his consulting firm (Larch Lab) prepared for the city of Vancouver, from January 2022.

More

• Conrad Speckert’s secondegress.ca website

• Video: Conrad Speckert discussing the current building code. Unlike continental European countries, which had to start over after WWII, the rules in the Canadian building code go back 100 years.

• Earlier posts: single-stair design, European middle-class flats

• Originally posted as a Twitter thread