Accessory Structures in Pasco, WA (2026)
4 verified accessory structures rules for Pasco, Washington, sourced directly from the municipal code and official government pages.
Verified from official government sources
ADU Rules
Pasco allows one attached or one detached ADU on any residential lot with a legal single-family home, processed as a ministerial or administrative permit with no public hearing. Size is capped at 1,000 square feet or 55 percent of the primary home, whichever is less, with a 25-foot height limit.
Pasco Accessory Dwelling Unit Zoning Rules
Some RestrictionsPasco Municipal Code § 25.161.040(1), (5)(b)-(c)
Number of ADUs Per Parcel. A maximum of one attached or one detached ADU is permitted on residential parcels with legally permitted and conforming single-family dwellings; provided, that all the requirements of the PMC and applicable development regulations are met. ... Unit Size. The size of the ADUs shall not exceed 1,000 square feet or 55 percent of the total square footage of the primary re...
ADU Owner Occupancy
Pasco does not require owner-occupancy to build an accessory dwelling unit, but it offers owner-occupancy as one path to a reduced fire-separation standard for an attached ADU built inside an existing home. Choosing it means recording an owner-occupancy agreement on the property title.
Pasco ADU Owner-Occupancy Fire Option
Light RestrictionsPasco Municipal Code § 25.161.040(6)(d)(ii)(B)
Applicants may consider the following alternatives from the above if documentation meets all three criteria below per Washington State Amendments to the IRC: ... Either the accessory dwelling unit or primary dwelling unit is owner-occupied. This will require recording on title of an owner occupancy agreement to assure proper use now and with potential future ownership.
ADU Rental Restrictions
Pasco requires accessory dwelling units to be occupied on a long-term residential basis only. PMC 25.161.040(3)(b) bars transient or short-term vacation rental use and requires occupants to live in the unit more than 180 days each calendar year.
Pasco ADUs Barred From Short-Term Rental
Significant RestrictionsPMC 25.161.040(3)(b)
(3) Occupancy and Use. (a) Occupancy of ADUs shall be reserved for residential uses only. (b) Occupancy of ADUs shall be used for long-term residential purposes and may not be used for transient occupancy or short-term/vacation rental purposes. Persons residing in ADUs shall live in such residences for longer than 180 days each calendar year. (c) Use of ADUs for uses outside of the permitted us...
Shed & Carport Rules
In Pasco's R-15 low density district, storage buildings are capped at 480 square feet total and 15 feet in height, with container storage barred entirely. Citywide, accessory structures like sheds must sit at least 5 feet from rear and side lot lines under the standard setback table.
Pasco Backyard Shed Size and Setback Rules
Some RestrictionsPasco Municipal Code § 25.30.030(3)
Storage buildings cumulatively not exceeding 480 square feet of gross floor area and 15 feet in height; provided no container storage, as defined in PMC 25.15.210, shall be permitted;
Looking for Franklin County county-wide rules?
County ordinances apply to unincorporated areas and may supplement Pasco city rules.
Accessory Structures in Franklin County →