CECC member SAR+ engages with the Colorado House of Representative to help create this act.

Excerpted from the Denver Post article of February 24, 2024.

As Sean Jursnick traveled through Europe, he marveled at its buildings. The Denver-based architect was particularly struck by a type of development that’s largely illegal in the United States: taller apartment buildings with just a single staircase.

Such buildings often feature apartments or condos situated around a central flight of stairs, with front doors opening directly onto landings. The layout allows flexibility and new development options in tight urban spaces, but it runs counter to decades-old fire-safety rules here that require housing developments rising higher than three stories to have at least two stairways.

The result has been that larger apartment buildings typically follow a standard, hotel-like model that calls for construction on big lots and, on the inside, long central corridors with units on either side. Often, each unit gets sunlight through its windows from just one direction.

“It’s a wild discrepancy between what we can do in the U.S. and what the rest of the world does,” said Jursnick, who works primarily in multi-family housing.

Under a bill introduced in the Colorado House this month, Jursnick and a growing group of single-stair evangelists see reason for hope. The measure would allow single-stair developments to reach up to five stories in the state’s cities and counties, potentially making Colorado the first U.S. state to do so.

The measure, backed by Denver Democratic Rep. Alex Valdez, is part of a broader effort by state legislators to embrace denser development and to pursue nontraditional policy avenues to solve the state’s housing crisis. The shortage of apartments has been estimated to run into the tens of thousands statewide.

Valdez called single-stair development the “anti-slot home” — referring to the boxy, sideways-facing townhomes that proliferated in Denver in the 2010s — because it allows more apartments or condos to be built on similarly sized lots. But for now, that layout is available only up to three stories for new construction.

Jursnick, after seeing so many taller structures of that type in Europe, traveled to Seattle, one of the few U.S. cities that’s legalized mid-sized single-stair buildings. He looked at that city’s unique housing types, the use of smaller lots and the fire safety rules modified to allow them.

He came away determined.

“I wanted to bring that back to Denver and create something that good in Denver,” he said.

Excerpted from the Denver Post article of May 13, 2025.

Gov. Jared Polis signs law that will bring more single-stair apartment buildings to Denver

House Bill 1273 will allow five-story buildings with one staircase instead of two.

Single-stair reform has come to Colorado — or it’s on its way, by Dec. 1, 2027.

That’s when Colorado cities of at least 100,000 residents will have to adjust their housing codes to allow for up to five-story apartment buildings with just one stairwell exit, under legislation signed into law Tuesday by Gov. Jared Polis.

“It’s simply by design — smart design — that we are necessarily creating more affordable housing options for Coloradans in a way that is safe and meets our expectations for what community should look like here in our state,” Rep. Andy Boesenecker, a Fort Collins Democrat, said during a bill signing ceremony in Denver. He stood outside a three-story, single-stair development near East Colfax Avenue and Colorado Boulevard.

Boesenecker and three other Democratic lawmakers sponsored House Bill 1273, which advances single-stair reform statewide. Current law allows for up to three stories for single-stair buildings, with a second stairwell required for taller buildings.

Proponents argue that allowing for larger developments with a single stairwell will spur the building of more housing units. And more uniquely designed properties — freed from double-barreled stairwells — will open up small urban lots for infill development.

Boesenecker also argued that building a second stairwell not only chews up space that could be used for apartments, it also adds between 6% and 13% to the total cost of the development.