Building permits in Washington County, Oregon
Find the right authority before you build. Washington County permitting follows Oregon law — here is exactly who issues the permit and where to start.
County + cities (mixed)
Washington County Building & Development Application Services
Washington County Building & Development Application Services issues permits for unincorporated Washington County and many contract cities via its BDAS/ProjectDox portal. Some cities (e.g., Hillsboro, Beaverton) may issue their own permits — confirm with your city.
Open the official permit portal →
The county enforces the State of Oregon Building Code (ORSC, OSSC, OPSC, OESC, OMSC) with Washington County code modifications.
Permit cheat-sheet (Oregon rules)
| Project | Permit? | Authority | Typical fee | Timeline | Go / No-Go | Key notes |
|---|---|---|---|---|---|---|
| 🏠 Accessory Dwelling Unit (ADU) | Permit required | city | Valuation-based building + trade permits per the local fee schedule. | Plan review; Portland and other cities review ADUs under standard residential review (weeks). | Generally allowed | Oregon’s HB 2001 (2019) requires cities (generally those over 10,000 population) to allow accessory dwelling units in single-family zones, so ADUs are broadly permitted statewide. Local zoning still sets size, setbacks, parking, and owner-occupancy rules — verify with your city. Exempt: Oregon HB 2001 requires most cities to allow ADUs in single-family zones (size/number set locally). |
| 🪵 Deck / Porch | Conditional | city | Valuation-based; Portland permit fees follow the city building-permit fee schedule. | Over-the-counter for low decks; plan review for elevated decks. | Generally allowed | Oregon’s seismic-active status means deck ledger and connection details are inspected; footnote to local frost/soil conditions. Exempt: Porches/decks ≤30 in above adjacent grade are exempt (statewide). Portland: decks/stairs >30 in above grade require a permit. |
| 🧱 Fence / Wall | Conditional | city | Often no building permit under the height threshold; permit fee only if over threshold. | Over-the-counter / zoning review for tall fences. | Generally allowed | Pool-barrier fences are never exempt and must meet barrier requirements. HOA rules may be stricter. Exempt: Wood, wire-mesh, or chain-link fences <7 ft are exempt (statewide). |
| 🛖 Shed / Outbuilding | Conditional | city | Valuation-based when over the exemption size; small sheds may avoid a building permit. | Small exempt sheds need no permit; permitted sheds go through plan review. | Generally allowed | Even exempt sheds must comply with zoning setbacks and lot coverage; adding electrical/plumbing/mechanical needs separate permits regardless of size. Exempt: Nonhabitable, detached, one-story sheds <200 sq ft and <15 ft tall are exempt (statewide). Portland exempts up to 200 sq ft / 15 ft, or 400 sq ft on lots >2 acres set back 20 ft. |
| 🪜 Basement Finish | Permit required | city | Valuation-based; includes trade permits. | Standard plan review 2–4 weeks. | Generally allowed | Creating living space in a basement triggers framing, electrical, insulation, and egress-window requirements under the ORSC. Exempt: Cosmetic finishing (paint, flooring) is exempt. |
| 🚗 Garage / Carport | Permit required | city | Valuation-based; includes trade permits. | New-structure plan review; varies by city. | Generally allowed | Attached and detached garages over the threshold require a full building permit and plan review. Exempt: Building or moving a carport, garage, or shed over 200 sq ft requires a permit. |
| ☀️ Rooftop Solar PV | Permit required | city | Building + electrical permits; fee set by the city. Oregon has solar-ready provisions (ORSC Appendix U). | Rooftop PV review typically quick once structural/electrical docs are submitted. | Generally allowed | Oregon’s ORSC includes solar-ready provisions; structural attachment and seismic/wind loads are reviewed. The state has strong pro-solar policies but permits are still required. Exempt: No size exemption; rooftop PV requires building and electrical permits. |
| 🌡️ HVAC Replacement | Conditional | city | Mechanical permit; fee set by the city (Portland publishes a mechanical permit fee schedule). | Trade permits often issued same-day/over-the-counter for in-kind replacements. | Generally allowed | Oregon’s energy code is strict — heat pumps and high-efficiency equipment are favored; equipment must meet ORSC energy provisions. Exempt: Installing/replacing a furnace, AC, ductwork, or gas piping requires a mechanical permit. |
| 🍳 Kitchen Remodel | Conditional | city | Valuation-based when structural/plumbing/electrical work is included. | Standard review for permitted scopes. | Generally allowed | Plumbing follows the Oregon Plumbing Specialty Code; electrical follows the Oregon Electrical Specialty Code (separate from the ORSC). Exempt: Cabinet/countertop swap in the same layout is exempt. |
| 🛁 Bathroom Remodel | Conditional | city | Valuation-based when plumbing is relocated. | Standard review for permitted scopes. | Generally allowed | Ventilation to the exterior required; plumbing under the Oregon Plumbing Specialty Code. Exempt: Fixture-for-fixture swap in place is often exempt. |
| 🏗️ Room Addition | Permit required | city | Valuation-based; includes trade permits and impact fees. | Plan review several weeks. | Generally allowed | Oregon’s energy code applies to additions; seismic/wind design criteria are site-specific via the Oregon Design Criteria Hub. Exempt: No exemption — any new conditioned footprint requires a permit. |
| 🪟 Window / Door Replacement | Conditional | city | Usually no fee for in-kind swap; permit needed if opening is enlarged or structurally changed. | In-kind swaps typically need no review. | Generally allowed | Replacement products must meet ORSC energy/glazing requirements when the code is triggered. Exempt: Replacing doors/windows with no structural changes is exempt (statewide). |
| 🏘️ Roof Replacement | Conditional | city | Often over-the-counter or exempt for same-footprint re-roof. | Re-roof often processed quickly. | Generally allowed | Oregon’s wildfire-zone provisions (ORSC R327) can require fire-resistant roofing in designated hazard areas. Exempt: Re-roofing is exempt where the replacement weight ≤30% of roof live-load capacity and fire-resistance is not required; full tear-off with new sheathing requires a permit. |
| 🅿️ Driveway / Parking Pad | Conditional | city | Building permit often not required; curb-cut/right-of-way work is separate and may need a public-works permit. | Right-of-way permits reviewed by the city/public works. | Generally allowed | A separate right-of-way permit is usually needed to cut the curb or connect to the street. Exempt: Private concrete sidewalk/slab/driveway not >30 in above grade and not over a basement is exempt (statewide). |
| 🏊 Swimming Pool / Spa | Permit required | city | Valuation-based; includes barrier/fencing and electrical bonding review. | Plan review several weeks; barrier inspection required before filling. | Generally allowed | Oregon pool-barrier rules apply; electrical bonding under the Oregon Electrical Specialty Code. Exempt: Prefabricated pools entirely above adjacent grade are exempt from a building permit, but the barrier around them is NOT exempt. In-ground/permanent pools always permitted. |
| 🧱 Retaining Wall | Conditional | city | Valuation-based when over the height threshold. | Over-threshold walls need plan review (engineering for surcharge). | Generally allowed | Oregon’s hillside/seismic conditions make engineered design important for taller walls. Exempt: Retaining walls >4 ft, or supporting a slope/drive/structure, require a permit (Portland). |
| 💥 Demolition / Teardown | Permit required | city | Demolition permit fee set by the issuing authority; verify locally. | — | Generally allowed | A full teardown or major strip-out requires a demolition (building) permit. Demolition permits commonly require proof of utility disconnects (water, gas, electric, sewer) and may require asbestos/lead-paint clearance for pre-1978 homes before work begins. Verify the issuing authority for your specific property. |
| 🚰 Septic System | Permit required | state | Septic permit fee set by Oregon DEQ; based on system type and design flow. | — | Generally allowed | New or replacement onsite wastewater (septic) systems are permitted by the Oregon Department of Environmental Quality (DEQ) Onsite Wastewater Management Program — directly in Curry, Jackson, and Josephine counties, and through local contract agents in the other 33 counties. A site evaluation and engineered design are required; licensed installers perform the work and the system is inspected before backfill. |
| 🔌 EV Charger | Conditional | city | Electrical permit; fee set by the issuing authority. | — | Generally allowed | A home EV charging station (240V branch circuit + wall-mounted EVSE) requires an electrical permit and must meet the Oregon Electrical Specialty Code (Article 625). Many jurisdictions fast-track residential EVSE. A load calculation and possible service upgrade are reviewed. |
| ⚡ Standby Generator | Conditional | city | Mechanical/electrical permit; fee set by the issuing authority. | — | Generally allowed | A permanently installed standby generator requires mechanical and electrical permits (transfer switch, fuel gas/propane line). Setback, carbon-monoxide ventilation, and noise rules apply; some HOAs restrict generator placement. |
Frequently asked questions
Who issues building permits in Washington County, Oregon?
Washington County Building & Development Application Services is the permitting authority for Washington County. Permitting is split — cities issue for incorporated areas, the county for unincorporated areas. Start at the official portal linked above.
Do I go to the county or my city for a building permit in Washington County?
Permitting is split — cities issue for incorporated areas, the county for unincorporated areas.
What home projects need a permit in Washington County?
The same project types shown in the cheat-sheet above (ADU, deck, fence, shed, solar, and more) — rules follow Oregon state law. Whether the county or your city issues it depends on your property's incorporation status.
How do I apply for a permit in Washington County?
Use the official permit portal linked above. Most offices accept online submissions; have your plans, site information, and contractor details ready before applying.
Sources: Washington County, OR — Building & Development Application Services · Oregon Building Codes Division — 2023 ORSC Update Resources · Oregon BCD — About Oregon Residential Building Permits · ICC — Oregon Adopted Codes · Portland Permitting & Development — Garages, Sheds & Accessory Structures