Policymaker Starter Kit
Empowering policy makers leaders with the tools to understand and implement single-stair reform.
Single-Stair Building Code Reform in North Carolina
For several years, North Carolina lawmakers have considered updates to the State Building Code that would allow single-stair apartment buildings, but those proposals have not yet been adopted. As housing costs continue to rise and population growth accelerates, Senate Bill 492 represents a renewed and more clearly defined effort to modernize building safety rules in a way that expands housing options without weakening life-safety standards.
SB492: North Carolina’s Single-stair Bill
This proposed legislation updates how small and mid-sized apartment buildings may be designed by allowing a single exit stairway under strict conditions. The goal is to make it easier to build safe, lower-cost, neighborhood-scale multifamily housing—the kind of housing North Carolina built historically and that remains common in many U.S. cities and abroad today.
What are Single-stair buildings?
Single-stair legislation will apply to buildings in Group R-2. In the North Carolina Building Code, Group R-2 refers to multifamily residential buildings where people live independently in separate dwelling units. This category includes:
- Apartment buildings
- Condominiums
- Mixed-use buildings with residential units above non-residential space
Group R-2 does not include:
- Single-family homes
- Duplexes, triplexes, or fourplexes regulated under the Residential Code
Single-stair reform applies only to Group R-2 multifamily buildings, which are already regulated under the commercial Building Code and subject to higher fire-safety standards than small residential structures.
What the Legislation Does
Allows Single-Stair Apartment Buildings
The bill permits certain Group R-2 buildings to be served by one exit stairway instead of two, when enhanced fire protection, smoke control, and egress requirements are met.
Defines Which Buildings Qualify
The reform applies only to buildings that:
- Contain 5 to 32 homes
- Are 75 feet tall or less
- Are located on a single lot
- Exclude 3–4 unit buildings governed by the Residential Code
Two Building Types Are Eligible
Mid-Rise Single-Stair Buildings
- Up to 8 stories total (7 above grade)
- Maximum 4 homes per floor
- Two-hour fire-rated construction
- Full NFPA 13 sprinkler system throughout
Low-Rise Single-Stair Buildings
- Up to 3 stories total (2 above grade)
- Maximum 6 homes per floor
- One-hour fire-rated construction or full NFPA 13 sprinklers
Safety and Egress Requirements
All qualifying buildings must meet additional life-safety standards, including:
- Residential-type sprinklers in all dwelling units
- Pressurized interior stairwells or approved engineered equivalents
- Maximum 20 feet from any apartment door to the stair
- Maximum 125 feet total travel distance to the public way
- Fire-rated doors and protected stair openings
- Exit discharge paths that do not pass through other occupancies
These measures are designed to provide a level of safety comparable to—or greater than—many existing multifamily buildings that already meet the Building Code.
Limits on Mixed Uses
- Non-residential uses must be fully separated from the residential portion
- Parking garages and occupied roofs may connect to the stair
- Exit stairs may not discharge through other occupancies
How This Fits Into the Building Code
- Buildings that meet these requirements are deemed compliant with state and local means-of-egress rules
- The legislation provides temporary authority to allow single-stair buildings
- The NC Building Code Council is directed to adopt permanent, substantively identical rules
- Temporary provisions sunset once permanent rules take effect
Why This Matters for North Carolina
Allowing single-stair apartment buildings makes it possible to:
- Build smaller, neighborhood-scale apartment buildings
- Deliver family-sized homes that are difficult to achieve under current rules
- Reduce construction costs without reducing safety
- Support walkable, mixed-income communities
- Increase housing supply without changing local zoning or density limits
This legislation focuses on building safety reform, not land-use mandates—giving communities more flexibility to meet housing needs while maintaining strong life-safety protections.
Single-Stair Housing: Proven and Nationally Adopted Standards
Across the United States, cities and states are modernizing building codes to allow small, well-protected apartment buildings to be served by a single exit stair. These reforms respond to housing shortages while maintaining — and in many cases strengthening — fire and life-safety standards.
North Carolina’s proposed single-stair reforms align closely with what has already been adopted in peer jurisdictions.
Where Single-Stair Housing Is Already Legal
Single-stair residential buildings are permitted today in:
- Seattle, WA
- New York City, NY
- Honolulu, HI
- Nashville, TN
- Austin, TX
- Baltimore, MD
- Denver, CO
- Montana (statewide)
These jurisdictions include a mix of:
- Large cities
- Growing Sun Belt metros
- Dense urban environments
- Statewide code systems
Importantly, these reforms were adopted by local governments and legislatures, not as experimental pilots.
What These Jurisdictions Have in Common
Despite local variation, nearly all adopted single-stair codes share a common safety framework. These measures appear consistently across cities and states:
- Limited building height (typically 4–6 stories)
- Residential use only (Group R-2 apartments, not hotels)
- No more than 4 dwelling units per floor
- Full-building automatic sprinklers
- Very short distance to the stair (commonly 20 feet from unit door)
- Maximum exit access travel distance (typically 125 feet)
- Fire-rated stair enclosure (often 2-hour rated)
- Fire-rated corridors and unit doors
- Separation from other uses (retail, parking, etc.)
- Emergency escape windows in every unit
In many cases, these jurisdictions add protections beyond standard code requirements, such as stair pressurization, smokeproof enclosures, or enhanced sprinkler coverage.
Fire Service Concerns and How Codes Address Them
Fire officials across the country have raised consistent concerns about single-stair buildings. The adopted codes directly respond to those concerns.
Common firefighter concerns include:
- Loss of redundancy with only one stair
- Potential stairway compromise from smoke or heat
- Evacuation and fire attack occurring in the same space
- Higher dependence on building systems performing correctly
How adopted codes respond:
- Buildings are small by design, limiting occupants and fire size
- Sprinklers control fires early, often before evacuation is required
- Stairways are fire-rated, enclosed, and often pressurized
- Travel distances are far shorter than in many two-stair buildings
- Uses are restricted to avoid higher-risk occupancies
The result is a re-balancing of safety, not a reduction.
How North Carolina Compares
North Carolina’s proposed single-stair standards are consistent with national practice:
- They follow the same building size limits
- They require the same core fire-protection measures
- They align with jurisdictions that have already implemented reform
- They remain within the framework of modern U.S. building codes
In short, North Carolina is not lowering standards it’s catching up.
Why This Matters for North Carolina
Single-stair housing enables:
- Small apartment buildings that fit existing neighborhoods
- More family-sized units and better layouts
- Lower construction costs without compromising safety
- Incremental, “missing middle” housing that large projects cannot provide
These outcomes are already being delivered elsewhere — safely, legally, and at scale.
Key Takeaway for Policymakers
Single-stair housing is:
- Not new
- Not experimental
- Already regulated
- Already built safely across the U.S.
North Carolina’s proposed reforms meet the same standards that other cities and states are already using to expand housing supply while maintaining strong life-safety protections.