MEP permit drawings in Washington.

The Washington State Building Code Council adopts the building, residential, mechanical, fuel gas, plumbing and energy codes statewide, with Washington amendments. The 2021 Washington State Energy Code took effect on March 15, 2024, and it pushes hard toward heat pumps and high-efficiency systems. Electrical work follows the NEC as adopted by the Department of Labor & Industries, and some cities, including Seattle, run their own electrical and energy programs.

• Building & residential — IBC and IRC with Washington amendments
• Mechanical & fuel gas — IMC and IFGC with Washington amendments
• Plumbing — Uniform Plumbing Code (UPC) with Washington amendments, not the IPC
• Energy — Washington State Energy Code (WSEC), residential and commercial provisions
• Electrical — NEC with Washington rules, administered by L&I or by cities with their own electrical programs
• Seattle — Seattle Building, Mechanical, Energy and Electrical Codes enforced by SDCI

Washington is one of the few states that uses the Uniform Plumbing Code, so pipe sizing and venting follow UPC tables. Plumbing drawings copied from an IPC state won't pass review.

• Seattle — Seattle Department of Construction and Inspections (SDCI), with the Seattle Energy Code and Seattle Electrical Code
• Bellevue — Development Services, with plan review for the Eastside's commercial and multifamily growth
• Tacoma — Planning and Development Services
• Spokane — Development Services Center
• Vancouver, Everett, Kent & Renton — each city's building or community development department
• King, Pierce, Snohomish & Clark counties — plus unincorporated county areas and every other Washington city

Electrical permits in Washington may be issued by L&I or by the city, depending on where you're building. We confirm which agency reviews your electrical drawings.

• Heat pump-based HVAC — the WSEC strongly favors or requires heat pumps for space and water heating in many building types, and fossil-fuel systems face limits.
• Residential energy credits — new homes must earn energy credits from a WSEC menu, and the selected credits have to show up on the mechanical and plumbing sheets.
• Commercial energy compliance — HVAC system efficiency, controls, lighting and commissioning requirements documented to the WSEC.
• UPC plumbing design — fixture-unit sizing, venting and water-heater details under the Uniform Plumbing Code.
• Ventilation — whole-house and commercial ventilation design, with balanced or heat-recovery ventilation where the code calls for it.

• Electrical — power and lighting plans, panel schedules, load calculations and single-line/riser diagrams (NEC with Washington rules)
• Plumbing — fixture layouts, water supply sizing, DWV isometrics and gas piping (Uniform Plumbing Code)
• HVAC / mechanical — duct layouts, equipment schedules, ventilation and Manual J/S/D load calculations (IMC with Washington amendments)
• Energy compliance — Washington State Energy Code compliance documentation, residential energy credits and Manual J/S/D calculations
• Fire protection — sprinkler layouts, hydraulic calculations and fire alarm plans (NFPA 13/13R/13D, NFPA 72) where your project needs them

Trade-specific details: electrical, plumbing, HVAC and fire protection permit drawings.

Washington requires sealed drawings from a Washington-licensed professional for many commercial and larger multifamily projects. Most single-family residential work can be permitted without an engineer's seal. Seattle and other cities set their own submittal thresholds.

Engineers who seal drawings in Washington are licensed by the Washington State Board of Registration for Professional Engineers and Land Surveyors. If your project needs sealed MEP drawings, we confirm during scoping whether a Washington-licensed engineer can seal your discipline and scope, and we put that in writing in your quote. If we can't arrange the seal for your project, we tell you up front, so you can have your own engineer of record review and seal the set. You never pay for drawings you can't submit.

1. Free consultation — tell us about the project, the address and the permit office.
2. Send your plans — architectural floor plans in PDF or DWG (sketches work for small residential jobs).
3. Code check & fixed quote — we confirm the code editions and submittal checklist your Washington AHJ uses, then send a fixed price and timeline.
4. Drafting & your review — residential sets usually take 5–7 business days, light commercial 7–14. You mark up, we revise.
5. Submittal & plan-review comments — you get PDF and DWG files ready to upload; if the reviewer issues comments, we revise the drawings at no extra charge until approval.