Effective Jan. 31, the Oregon Residential Specialty Code allows a stacked, two-family dwelling to be attached to another stacked two-family dwelling (for a total of four dwelling units), without sprinklers. Previously, four-unit housing buildings were required to be built under the more stringent standards of the Oregon Structural Specialty Code, which applies to commercial buildings.
Three or more stacked two-family dwellings (for a total of six or more dwelling units), attached to one another, will require National Fire Protection Association (NFPA) 13D sprinklers throughout all units.
The separation wall between each stacked two-family dwelling will resist the spread of fire for at least two hours.
This project type is limited to two-story structures. First-floor units must be accessible to wheelchair users. The City of Portland, through its Building Code Guide for townhouses (BCG 19-11), allows three- and four-story two-family dwellings to be attached to one another under some circumstances.
In its temporary administrative order, BCD noted, “This temporary rule is intended to meet the stated industry desire of simpler, small footprint, ‘apartment-type’ designs being available while the division supports our Governor’s housing initiatives and related statewide housing production goals before the permanent amendments can be filed. The approach is intended to accomplish this while still accommodating simple designs, easy to follow prescriptive provisions, flexible options and reasonable levels of fire and life safety.”
Permit requests for these new types of housing units are now being accepted by the City of Portland. Those interested in building these types of units are encouraged, before submitting a permit application, to schedule two separate 15-minute appointments with City development review staff:
- With a city planner to discuss zoning allowances and requirements
- With a residential building code reviewer to discuss building code requirements
When applying for a permit for attached, stacked two-family dwellings through Development Hub PDX, customers should select a residential new construction permit for a two-family dwelling property and indicate the new single family residential (NSFR) intake process.
These new types of residential developments are allowed through a temporary administrative rule adopted by BCD that is in effect through July 29. BCD is expected to engage in a permanent rulemaking process on this topic before the expiration of this temporary rule. Those interested in engaging in that rulemaking effort should contact BCD for more information.
Learn more about the temporary rule adopted by BCD for stacked and attached duplexes (two-family dwellings).