State Building Code.
The State Building Code (SBC) provides a set of minimum statewide standards and requirements for buildings.  The SBC is comprised of several different codes.  Most of these codes are international model codes that the Legislature has adopted by reference in statute, including the International Building Code (IBC), the International Residential Code (IRC), the International Mechanical Code, the International Fire Code, portions of the International Wildland Urban Interface Code, and the Uniform Plumbing Code.  The SBC also includes certain state-created standards for making buildings accessible to individuals with disabilities or elderly persons, and the State Energy Code.
 
The State Building Code Council (Council) is responsible for adopting, amending, and maintaining the SBC through the rulemaking process under the Administrative Procedure Act.  Amendments to the SBC adopted by the Council are codified in the Washington Administrative Code.  The Council periodically reviews updated editions of the model codes for potential adoption in the SBC.  For example, the 2018 model codes, with state amendments, are currently in effect.  After a multiyear review and rulemaking process, the 2021 model codes, with state amendments, are set to take effect July 1, 2023.
 
Local Amendments to the State Building Code.
The governing body of each county or city is authorized to amend the SBC as it applies within the local jurisdiction.  However, the local amendments must not result in code requirements that are less than the minimum SBC standards, with certain exceptions.  For example, a county or city may adopt amendments that eliminate or reduce minimum gross floor area requirements for single-family detached dwellings.  The Council must review and approve or deny all proposed local amendments that apply to single-family or multifamily residential buildings, with certain exceptions.
 
International Residential Code.
The IRC was created to serve as a comprehensive code regulating the construction of single-family houses, two-family houses, and townhouses.  The IRC does not include occupancy classifications.  All buildings within the scope of the IRC are limited to three stories above grade plane.  For example, a four-story single-family house would fall outside the scope of the IRC and into the scope of the IBC.  Detached one- and two-family dwellings and townhouses that are not more than three stories above grade plane have the option of complying with either the IBC or the IRC.  
 
International Building Code.
The IBC establishes minimum standards and requirements for construction of all buildings, except for detached one- and two-family dwellings and townhouses that are not more than three stories above grade plane.  The IBC classifies buildings into use groups and occupancies based on the primary purpose of the building and the nature of the hazards and risks to building occupants generally associated with the intended purpose of the building.  Throughout the IBC, occupancy classification is important for establishing construction requirements, occupant safety requirements, means of egress, fire protection systems, and interior finishes.  The residential group R-2 occupancy classification applies to buildings containing sleeping units or more than two dwelling units where the occupants are primarily permanent in nature, such as apartments and certain congregate living facilities. 
 
International Building Code Criteria for Means of Egress.
The IBC provides general criteria for designing the means of egress or exit from a building.  The means of egress from a building is the primary method for protection of people in the building by allowing timely relocation or evacuation of building occupants.  The IBC egress requirements provide an approach for determining a safe exiting system for all occupancies that works in coordination with other sections of the IBC that have an impact on life safety, such as the requirements for protection of vertical openings, interior finishes, and fire suppression and detection systems. 
 
Under the IBC requirements for single exits that apply to residential group R-2 occupancies, a single exit or access to a single exit is permitted from the basement, first, second, or third story above grade plane where the maximum number of dwelling units per story is four, and the maximum common path of egress travel distance is 125 feet.  For the fourth story above grade plane and higher, more than one exit is required.  Additionally, buildings classified as group R-2 occupancies must be equipped throughout with an automatic sprinkler system and emergency escape and rescue openings in accordance with other IBC requirements.

The Council must convene a technical advisory group for the purpose of recommending modifications and limitations to the IBC that would allow for a single-exit stairway to serve multifamily residential structures up to six stories above grade plane.  The recommendations must include considerations for adequate and available water supply, the presence and response time of a professional fire department, and any other provisions necessary to ensure public health, safety, and general welfare.  The technical advisory group must provide its recommendations to the Council in time for the Council to adopt or amend rules or codes as necessary for implementation in the 2024 IBC.  The Council must take action to adopt additions and amendments to rules or codes as necessary by July 1, 2026.

(In support) This bill allows taller single-stairway buildings.  Generally, the traditional multifamily building has two stairways for ingress and egress as a fire safety measure.  This bill takes what is legal in Washington state—a three-story single-stairway building—and increases it a little bit, with conditions.

The City of Seattle has authorized single-stairway buildings successfully with the provisions in this bill to ensure fire safety.  This is an option that can be done safely.  This applies to very small multifamily buildings where one of the stairways can be eliminated if the building complies with strict, prescriptive requirements:  four units per floor, sprinklers, and fire-resistance rating.  Some countries in the European Union do not require sprinklers until the building is a high rise.  These are not big buildings or high rises.  They have an exemplary safety record.  They vary from four units to 10 units.  They vary from studios to three bedrooms.  All of these sites are either single parcels, such as 5,000 square-foot lots or smaller.  The idea is that with a single stairway any type of urban infill project is much more viable.

This bill helps affordability because it allows more housing units out of the buildable structure without having to set aside space for a second staircase.  Having a second stairway means less windows, fewer units, less ventilation, more blank exterior walls, and ultimately higher rent because the buildings are less efficient from the square-footage standpoint.  Taller single-stairway buildings unlock more small- and medium-size development without the need for parcel assemblage, which is a process that increases costs and time of development.  This will allow infill development without needing to accumulate multiple properties, which will allow a lot of gentle density to be added.  The bill provides another opportunity to meet housing needs especially in dense areas.  Habitat for Humanity has two single-stairway projects in Seattle right now:  a four-story building and a five-story building.

This bill also allows for family units that take up an entire floor because there isn't a requirement to put a hallway down the middle of the development that would bisect the unit.  Sometimes these buildings have a staircase that wraps around the building going upward.  This is a beautiful way to do apartments that is common in Portugal.

 
The United States is an extreme outlier when it comes to designing multifamily buildings.  The building code results in narrow units that do not have daylight on multiple sides and do not have multiple means of ventilating the buildings.  This is generally not a good mix of units.  These types of building are nonexistent in Germany except as student housing and temporary housing.  In contrast, single-stairway housing from four to 10 floors is ubiquitous the world over:  not just in Europe, but also in South America, Tokyo, China, and Taiwan.  These buildings are everywhere.  In Germany and Switzerland, they make up 60 percent to 70 percent of all multifamily housing.

This bill means more affordable housing, more cost-effective construction, more compact buildings with lower embodied carbon, more climate-adaptive housing, more accessible and adaptable housing units, and more multigenerational and family-sized housing.  This bill provides a ton of flexibility for planners and developers.  The single-stairway provision will make more sites feasible and give architects more flexibility to create great buildings.

(Opposed) None.