Get a Seattle-adjusted cost estimate for your hvac project. Our calculator starts from national averages and applies a local cost index for Seattle, Washington based on labor market data and cost-of-living indices.
Local context for Seattle
Seattle permits are issued by the Seattle Department of Construction and Inspections (SDCI) through the Seattle Services Portal. Seattle enforces the 2021 Seattle Energy Code, which effectively eliminates fossil fuels for most space and water heating in new commercial and multifamily construction and requires electrification readiness on all new construction. Seattle also sits in high seismic zone D with specific lateral-bracing amendments.
Permits filed through Seattle Department of Construction and Inspections (SDCI) · official portal
These figures are estimates derived from national cost data and a local cost-of-living multiplier. They are not quotes. For a firm price, use the calculator below and then get 3+ written bids from licensed local contractors.
Several local factors push Seattle hvac pricing above or below the national baseline:
Can I install a gas furnace in a new Seattle home?
The 2021 Seattle Energy Code effectively requires heat pumps for space heating in most new construction. Gas is still allowed in existing homes for replacement, but new construction has to meet the all-electric or equivalent performance paths.
Do I need a permit to cut down a tree on my Seattle property?
Often yes. Seattle Municipal Code 25.11 protects Exceptional Trees and many Tier 2 trees based on species and size. SDCI and the Office of the Tree Service Provider Registration handle approval. Removing a protected tree without approval can trigger fines and replacement requirements.
Seattle Department of Construction and Inspections (SDCI) handles hvac permits in Seattle. Fees, inspection schedules, and code amendments vary by project scope.
Visit the official Seattle permit portal ↗For full system replacement in Seattle, most homeowners pay between $6,500 and $16,250 in 2026. Our estimates cover equipment, labor, and permits for typical installations. The biggest accuracy variable is ductwork — if your existing ducts need repair or replacement, add $2,000-$7,000 to the estimate.
Permit requirements in Seattle follow Washington state building code plus local amendments. For most homeowners, 17-18 SEER2 offers the best balance of upfront cost and energy savings. In hot climates where AC runs 6+ months, consider 19-20 SEER2 for faster payback on the efficiency premium. See our Washington permit guide for specifics.
In 2026, heat pumps are the better choice for most climates on operating cost alone. They heat AND cool (replacing both furnace and AC) and cost 30–50% less to operate. Note: the $2,000 federal Section 25C tax credit that incentivized heat pumps through 2025 expired December 31, 2025 under the One Big Beautiful Bill Act — systems placed in service in 2026 do not qualify. See our heat pump vs furnace comparison for the full math.
A straightforward equipment swap takes 1-2 days. If new ductwork is needed, expect 3-5 days. Switching system types (e.g., furnace to heat pump) takes 2-4 days.
Yes. HVAC replacement requires a mechanical permit in virtually all jurisdictions. Your contractor should handle this. Expect $150-$400 for the permit fee.
The 2021 Seattle Energy Code effectively requires heat pumps for space heating in most new construction. Gas is still allowed in existing homes for replacement, but new construction has to meet the all-electric or equivalent performance paths.
Often yes. Seattle Municipal Code 25.11 protects Exceptional Trees and many Tier 2 trees based on species and size. SDCI and the Office of the Tree Service Provider Registration handle approval. Removing a protected tree without approval can trigger fines and replacement requirements.