ADU rules in Grants Pass

Detached backyard ADUs are expressly allowed. Section 22.725 lets an ADU be created on a lot that has one single detached dwelling unit either by converting detached space (a detached garage or storage shed) or by adding a new detached unit, which the code says includes a unit built on the second story of, or beside, a detached garage. Article 12's Schedule 12-2 codes 'Accessory Dwelling Unit, per 22.720' as S-I-A in the R-1-12, R-1-10, R-1-8, R-1-6, R-2, R-3 and R-4 zones, covering every zone where a detached single dwelling can be built. There is no lot-size or density gate: section 22.730 exempts ADUs from the residential density standards, and section 22.732(1)(a) allows up to two ADUs per single dwelling unit per lot.

Attached and internal ADUs are allowed on the same terms as detached ones and through the same Type I-A building-permit path. Section 22.725(1)(a) permits conversion of attached space such as an attached garage, basement or attic, section 22.725(1)(c) permits converting an existing legal non-conforming structure so long as the non-conformity is not increased, and section 22.725(2)(a) permits adding new space attached to the single dwelling unit. Section 22.732(1)(b)(i) actually favors interior conversions by lifting the 1,000 sq ft cap for a converted whole floor. The single attached-specific design rule is section 22.732(1)(b)(ii): fire escapes or exterior stairs serving an attached upper-level ADU may not be placed on the front of the primary dwelling. Article 30 confirms an ADU plus its primary dwelling is not treated as a duplex.

Section 22.732(1)(b)(i) sets a flat 1,000 square foot ceiling with no percent-of-primary-dwelling formula and no per-zone variation. The exception is unusually generous: an ADU created by converting an entire level or floor of the primary dwelling (basement, attic or second story) may occupy that whole level even where the resulting floor area exceeds 1,000 square feet. Section 22.732(1)(a) permits two ADUs per single dwelling unit per lot, so one lot can carry up to 2,000 square feet of accessory dwelling. There is no ADU-specific height limit or setback reduction; the base zone standards apply, meaning 35 feet in R-1-12, R-1-10, R-1-8, R-1-6, R-2 and R-3 and 45 feet in R-4, R-4-2 and R-5 under Schedule 12-6, plus the yard setbacks in Schedule 12-5. For scale, the city's three pre-approved ADU plan sets are 728, 576 and 416 square feet.

The Development Code imposes no owner-occupancy requirement on either the house or the ADU, at application or on an ongoing basis. The only ownership rule is section 22.735(3), which bars subdividing or otherwise separating ownership of the ADU from ownership of the primary residence: that blocks a separate sale or condominium split but does not require anyone to live on site, and both units may be rented to tenants. State law backs this up. ORS 197A.425(1)(b)(B) provides that 'reasonable local regulations relating to siting and design' does not include owner-occupancy requirements of either the primary or accessory structure, so a local requirement would be void in any event. Grants Pass rewrote its ADU language in Ordinance 19-5757 (April 17, 2019), which the city's amendment log describes as its SB 1051 update. One narrow carve-out exists in principle: ORS 197A.425(2) lets cities require owner occupancy for vacation occupancies, but Grants Pass has not done so in its Vacation Rental Dwelling standards.

Two independent provisions make this a firm no. Section 22.731 states that accessory dwelling units are exempt from the off-street parking requirements of section 25.042; it still cites the repealed ORS 197.312(5), whose substance now sits at ORS 197A.425(1)(b)(B). Separately, Ordinance 24-5902 rewrote section 25.042 on May 15, 2024 so that, under Oregon's Climate Friendly and Equitable Communities rules at OAR 660-012-0420, off-street parking is not required by the Development Code for any use; the old parking table now reads as merely 'recommended' standards. Only the accessible-parking requirements of the Oregon Structural Specialty Code still apply. The one place parking still bites is short-term rental use: Article 14 section 14.830(5) requires off-street parking for a Vacation Rental Dwelling and caps vehicles in the driveway and on the street, which ORS 197A.425(2) expressly permits for vacation occupancies.

In every zone where a detached single dwelling can exist (R-1-12, R-1-10, R-1-8, R-1-6, R-2, R-3 and R-4), Schedule 12-2 codes an ADU as S-I-A. The table legend reads 'S = Secondary Use' and 'I-A = Type I Procedure, Building Permit Serves as Development Permit, Section 2.035', and section 2.035 confirms that Type I-A uses may use the building permit as the development permit provided the Code is met. There is no separate land use application, no public notice and no hearing, and the section 22.735 approval criteria are objective: meet the section 22.732 standards, meet building and fire safety codes, and do not separate ownership. The city's published ADU fee example (rates effective January 1 through December 31, 2026) is consistent, listing only building plan check, structural, electrical, mechanical and plumbing fees plus a 10 percent planning review surcharge and system development charges. Two narrower paths exist: Schedule 12-2 routes ADUs through a Planned Unit Development in the high-density R-4-2 and R-5 zones and codes them S-I-C (Type I, Director's decision with a public comment period, section 2.037) in the NC, GC, CBD and OR commercial zones. ADUs are not permitted in the BP, IP and I industrial zones.

Nothing in the Development Code sets a minimum lease term, caps how many ADUs may be rented or requires the owner to occupy either unit, so an ADU may be rented long term without restriction. Short-term rental is expressly allowed but regulated: section 14.830(6)(a) makes single family dwellings and accessory dwelling units the only structures eligible to be a Vacation Rental Dwelling, and Schedule 12-2 requires a VRD permit through a Type I-C procedure (Director's decision with a public comment period) in the R-1, R-2, R-3, R-4, GC and CBD zones, S-I-C in R-4-2 and R-5, and not at all in the NC, OR, BP, IP or I zones. VRD standards cap a stay at no more than 27 days in any 30-day period, limit overnight occupancy to two people per sleeping room plus two more up to a maximum of twelve, require off-street parking, and require a guest register, solid waste service and front-yard landscaping. The city's lodging tax under Municipal Code Chapter 4.05 applies. Finally, section 22.735(3) forbids subdividing or otherwise separating ownership of the ADU from the primary residence, so the ADU cannot be sold off, condominiumized or split onto its own lot.