'Single Stair' zoning reform, technical fix for affordable housing

'Single Stair' reform is a bit of a wonky zoning reform that can significant increase density and decrease building costs for multi-family housing.
https://www.planning.org/planning/2025/nov/how-a-single-stairway-can-take-affordable-housing-to-a-new-level/

Colorado made a bold housing move earlier this year: To encourage higher-density development and enhance the quality of life for apartment dwellers, the state enacted a law in May allowing multifamily buildings of up to five stories to be built with a single staircase instead of the two previously required for municipalities with populations exceeding 100,000.

Requiring fewer staircases — sometimes referred to as "smart stair" reform — can lower construction costs by hundreds of thousands of dollars per building, says Stephen Smith, executive director of the Center for Building in North America. Updating building codes to permit just one staircase also can allow apartments to have windows on more than one side for better ventilation, more daylight, and greater comfort for residents, according to Colorado legislators, citing a 2024 George Mason University study.