HVAC replacement cost in Seattle, WA

Average $7,500; common $5,000 to $12,500; up to $22,000 with new ductwork.

A typical HVAC replacement in Seattle, WA is about $8,392, including a permit fee of $126.73.

What we assumed

For the permit line we assumed Seattle SDCI 2026 Fee Subtitle Table D-8 mechanical equipment fees for a typical 2-unit like-for-like furnace/heat-pump change-out plus the 5% technology fee (SMC 22.900A.100), so the typical fee is $126.73. Low and high unit-count bands are in the calculation note on this page.

Questions about this estimate

How much does HVAC replacement cost in Seattle, WA?

Typical all-in is about $8,392. The official SDCI permit fee of $126.73 ($120.70 mechanical + $6.04 tech) is included in the all-in.

Is a permit required for HVAC replacement in Seattle, WA?

Yes. Seattle Department of Construction and Inspections (SDCI) requires a permit for a typical HVAC replacement in Seattle, WA. The typical listed fee is $126.73. The official path is Seattle SDCI Table D-8 (22.900D.090) mechanical equipment fees plus the 5% technology fee (SMC 22.900A.100), not valuation DFI.

What is included in this HVAC replacement estimate for Seattle, WA?

The estimate is labor adjusted for local wages in Seattle, WA, plus materials at the national figure, at the typical size in the table above. The official typical permit fee of $126.73 is included in the all-in typical. That fee is the Table D-8 mechanical equipment charge for a typical 2-unit change-out plus the 5% technology fee. Separate electrical and new-duct Table D-2 paths are not included.

Why might the Seattle permit fee differ from this typical figure?

The official Seattle, WA fee comes from Seattle SDCI 2026 Fee Subtitle (SMC 22.900), Table D-8 (22.900D.090) (flat). The typical path is $126.73 for a 2-unit like-for-like furnace/heat-pump change-out on Table D-8 plus the 5% technology fee, not valuation DFI. Low and high unit-count bands and alternate paths are in the calculation note on this page. Verify the mechanical path with Seattle Department of Construction and Inspections (SDCI).

How is the typical permit fee calculated for HVAC replacement in Seattle, WA?

Listed Table D-8 bands are low 1 unit $63.37, typical 2 units $126.73, and high 3 units $190.10, each including the 5% technology fee (SMC 22.900A.100). Full arithmetic is in the calculation note on this page.

What project value is this HVAC replacement permit fee based on in Seattle, WA?

The official typical project value is $7,500. This permit fee is the Table D-8 unit-count path, not a valuation (DFI) total. Low, typical, and high unit totals are in the calculation note on this page.

How much does HVAC replacement cost for 1, 2, or 3 systems in Seattle?

The documented typical job is a 3-ton (36,000 BTU) like-for-like split system. This cost model prices that job as one system. The cost-by-size rows include 1 system, 2 systems, and 3 systems. At 1 system in Seattle, WA the all-in is $5,573 low, $8,392 typical, and $24,434 high. Those all-in figures add the model's rounded permit for the official Table D-8 bands. The official fees are $63.37, $126.73, and $190.10. The model rounds each to the nearest dollar before adding it, so the all-in uses $63 on the low, $127 on the typical, and $190 on the high. The official permit line is the typical 2-unit Table D-8 path, so it is not rescaled when the system count changes. At 2 systems the all-in typical is $16,657, and at 3 systems it is $24,922.

What does the typical $126.73 HVAC permit fee include in Seattle?

The official typical HVAC permit in Seattle, WA is $126.73. That total is the Table D-8 mechanical equipment fee for 2 units ($120.70) plus the 5% technology fee ($6.04) under SMC 22.900A.100. Both extras are included in the typical fee, so they are not added again. Electrical (Table D-14 / OTC) and new duct systems on Table D-2 valuation are separate and are not part of that $126.73.

Why are the low, typical, and high HVAC permit fees $63.37, $126.73, and $190.10 in Seattle?

The low, typical, and high fees are three applications of the same Seattle SDCI Table D-8 (22.900D.090) per-unit path, not three different schedules. Table D-8 is $60.35 per forced-air furnace, heat pump, or similar unit, including ducts attached thereto. Low 1 unit: 1 × $60.35 × 1.05 → $63.37. Typical 2 units: 2 × $60.35 × 1.05 → $126.73. High 3 units: 3 × $60.35 × 1.05 → $190.10. That path is not the valuation DFI.

Is electrical included in the Seattle HVAC permit fee?

Electrical is separate on this listed row. The typical $126.73 is Table D-8 mechanical equipment plus the 5% technology fee only. A separate Table D-14 / OTC electrical permit if new circuits or disconnects was not listed as a fee line, and new duct systems submitted separately use Table D-2 valuation instead of Table D-8.

Is the Seattle HVAC permit a valuation (Table D-2 / DFI) fee?

No. The official Seattle HVAC path is Table D-8 (22.900D.090) mechanical equipment fees by unit count plus the 5% technology fee, not the valuation DFI and not Table D-2. New duct systems submitted separately use Table D-2 valuation, and that alternate is excluded from the official $63.37 / $126.73 / $190.10 bands. Confirm the path with Seattle Department of Construction and Inspections (SDCI).