ADU rules in Salem

Detached backyard ADUs are allowed as a 'special use' in every residential zone (RA, RS, RM-I, RM-II, RM-III), and the city also lists them in the commercial, industrial, mixed-use, and Neighborhood Hub zones. A special use in Salem is not a hearing: it is an outright-allowed use carrying extra written standards. SRC 700.007(b) supplies the detached-specific standards, which are the giveaway that detached units are contemplated: side or rear yard placement only, 12 ft from a local street (20 ft from a collector or arterial), 3 ft interior side, 5 ft interior rear (1 ft along an alley), 60 percent maximum total lot coverage, and 25 ft maximum height. Only one ADU is allowed per lot.

Attached and internal ADUs are allowed on the same footing as detached ones. SRC 111.001 defines an accessory dwelling unit as 'a second dwelling unit that is attached to or detached from a single-family detached dwelling, manufactured home, townhouse, or zero side yard dwelling on the same lot,' and SRC 700.007(a)(4) speaks directly to 'attached accessory dwelling units.' The city's ADU page gives a basement apartment and an apartment over the garage as examples. Attached units are governed only by the general standards in SRC 700.007(a); the setback, lot coverage, and 25 ft height rules in subsection (b) apply to detached units only. A converted unit must be a genuinely independent dwelling with its own kitchen and bathroom and no direct interior connection to the main house.

SRC 700.007(a)(2) sets a single citywide cap: an ADU 'shall not exceed 900 square feet, or 75 percent of the main building gross area, whichever is less.' The percentage test binds on smaller houses, so a 1,000 sq ft home yields a 750 sq ft maximum rather than 900. Detached units are additionally limited to 25 ft in height, and buildings plus accessory structures plus the ADU may not exceed 60 percent total lot coverage. There is no separate minimum lot size for an ADU except on townhouse lots, which must be at least 2,500 sq ft with no more than two townhouses attached in a row. The city's free ready-build plans are drawn to under 600 sq ft, comfortably inside the cap.

Salem imposes no owner-occupancy condition, at application or on an ongoing basis. SRC 700.007 contains no such requirement in any subsection, and the city's ADU page states plainly that tenants 'can live in an ADU permanently.' State law independently forecloses one: 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.' Salem's code and the statute agree here, so unlike some jurisdictions there is no void-but-uncodified provision to work around. The owner-occupancy style test in SRC 700.006 applies to accessory short-term rentals, which an ADU may not be.

No additional off-street parking is required for an ADU, and the reason is broader than ADU policy: Salem repealed its parking minimums outright. Ord. No. 4-23, adopted April 24, 2023, repealed former SRC 806.005 ('off-street parking; when required') and rewrote SRC 806.015 so that the only remaining table, Table 806-1, is a MAXIMUM off-street parking table. The ADU row in that table reads '1 per dwelling unit', which is a ceiling on how much parking may be built, not a floor. The city's ADU page states it twice: 'No off-street parking spaces are required for ADUs.' ORS 197A.425(1)(b)(B) separately bars Salem from requiring additional off-street parking as a condition of ADU approval, so the local and state positions align. ADUs also require no bicycle parking and no loading area.

Building permit only, with no land use application and no hearing. The zone use tables mark accessory dwelling units 'S' for special use, and SRC 700.005(c) is explicit that 'a special use that complies with the standards set forth in this chapter and with the applicable standards of the UDC does not require approval beyond that required for a use that is a permitted use.' The city's ADU page says the same: 'ADU is considered a special use, so no land use application process is required as long as you can meet the special use standards. You do need a building permit.' Review is therefore ministerial against the clear numeric standards in SRC 700.007. A project that cannot meet one of those standards does not go to conditional use; SRC 700.005(e)(1) routes ADU deviations to an adjustment (SRC ch. 250) or a variance (SRC ch. 245).

Renting an ADU long-term is expressly contemplated: the city's ADU page opens by addressing readers 'looking for long-term rental income' and confirms tenants may live in an ADU permanently. Short-term rental is flatly barred. SRC 700.007(a)(6) provides that ADUs 'shall be prohibited from being used as short-term rentals or accessory short-term rentals,' and SRC 700.006 closes the loop from the other direction by barring an accessory short-term rental inside an ADU and barring one on any lot where an ADU is being operated. Salem defines short-term rental as renting for periods of less than 30 days, so the practical rule is a 30-day minimum tenancy. The unit also cannot be split off and sold: SRC 700.007(a)(4) bars separating an ADU in ownership from the underlying property, including through condominium ownership.