Local research · updated July 2026
Casement windows in Seattle, Washington
Side-hinged sash that cranks outward like a door. For Seattle's mixed-age housing stock (54.2% of homes predate 1980), casement window replacement is a common project — and in the ENERGY STAR Northern zone, the number that matters most is a low U-factor (≤ 0.22) to keep heat in.
Short answer
Casement windows in Seattle typically cost $620–$2,825 installed per opening. The low end is a mid-grade vinyl insert from a regional installer; the top is a premium frame, a full-frame installation, or a full-service national brand.
NREL REMDB + BLS PPI, localized to Seattle (BEA Regional Price Parity, 2024). How we estimate →
$620–$2,825
installed range per opening for Casement window, from a mid-grade insert up to a premium or full-frame job
Source: NREL REMDB + BLS PPI, localized to Seattle
54.2%
of Seattle homes were built before 1980
Source: U.S. Census Bureau, 2019–2023 ACS 5-Year Estimates
U ≤ 0.22
the ENERGY STAR v7.0 number that matters most in the Northern zone
Source: EPA ENERGY STAR v7.0
Is a Casement window right for a Seattle home?
Crank handle swings the full sash outward; locks compress the seal.
Where it fits:
- Maximum ventilation — the whole opening opens
- Tightest air seal of the common operable styles (compression seal)
- Hard-to-reach placements like over kitchen sinks
What to weigh:
- Projects outward — check clearance to walkways and screens
- Hardware is the wear item; crank quality matters
- Width limits — very wide openings need mulled units
Casement windows and Seattle's climate
Seattle sits in the ENERGY STAR Northern zone (IECC zone 4C (marine), King County), where the priority is a low U-factor (≤ 0.22) to keep heat in.
A casement closes against a compression seal — the tightest of any operable window. In the Northern zone's cold winters, where air leakage drives heating loss, that seal is a real advantage.
New to these numbers? See our plain-English guide to U-factor and SHGC and the full casement guide.
What Casement windows cost in Seattle
Casement window replacement in Seattle runs $620–$2,825 installed. The low end is a mid-grade vinyl insert from a regional installer; the top is a premium frame, a full-frame installation, or a full-service national brand. Two local forces push Seattle quotes above what national averages assume. Labor is the first: install rates here are among the highest in the country, and on old homes that adds up fast. Frame condition is the second — pre-1940 wood windows with rot, out-of-square openings, or lead paint often force full-frame replacement plus repair rather than a quick insert. On the product side, Washington's energy code effectively requires Northern-zone glass, so budget bids built around basic double-pane rarely reflect what will actually pass permit. The offset is durability: getting water and air management right on a century-old frame solves the condensation and rot problem that keeps recurring.
That's the national range shifted to Seattle's cost level using the BEA Regional Price Parity for Seattle-Tacoma-Bellevue, WA (111.1, U.S. = 100; 2024). How we estimate local costs →
For a breakdown by frame material and install type, see our full cost guide.
Installers serving Seattle
A sample of companies with locations in the Seattle market. See the full Seattle directory for all listings, our map, and featured-partner disclosures.
| Company | Location | Request a quote |
|---|---|---|
 4.8 · 200,000+ reviews | Lakewood, WA | Get a quote → |
| 1Champion Replacement Windows of SeattleChampion | Kent, WA | Get matched → |
| 2Pella Windows and Doors Showroom of Bothell, WAPella | Bothell, WA | Get matched → |
| 3Pella Windows and Doors Showroom of Tacoma, WAPella | Tacoma, WA | Get matched → |
Renewal by Andersen of Western Washington
4.8 · 200,000+ reviewsShowrooms in Lakewood, Marysville & Renton · serving the Seattle metro
Full-service manufacturer and installer, transferable warranty, local crews. Why it's our Top Pick
Get a quote →Listings compiled from manufacturer dealer locators and public business records. Premier and Sponsored Partners pay for placement and are labeled as such; star ratings shown are reported by the partner, with the source and date beside them. See our advertising disclosure. Contacting a company shares your details with it (or a vetted local installer) so it can reach you about your project.
Are you a window company? Claim your listing to take quote requests from Seattle homeowners directly.
Rebates & incentives in Washington
The federal window tax credit (25C) ended for projects placed in service after December 31, 2025. If your windows were installed in 2025, you can still claim it on your 2025 return — but for new projects there is no federal window credit. State and utility programs are now the main source of window incentives.
Washington runs IRA Home Energy Rebate programs; whole-home efficiency retrofits can include windows. Confirm current status and funding availability before promising rebate money. See our Seattle guide for the full program list.
Casement windows in Seattle: FAQ
›What efficiency numbers should a Casement window in Seattle meet?
Seattle sits in the ENERGY STAR Northern zone (IECC 4C (marine)). Qualifying units need a U-factor of 0.22 or lower with an SHGC of at least 0.17. A casement closes against a compression seal — the tightest of any operable window. In the Northern zone's cold winters, where air leakage drives heating loss, that seal is a real advantage.
›How much does Casement window replacement cost in Seattle?
A useful planning range for Casement window replacement in Seattle is $620–$2,825 installed. The low end is a mid-grade vinyl insert from a regional installer; the top is a premium frame, a full-frame installation, or a full-service national brand. Two local forces push Seattle quotes above what national averages assume. Labor is the first: install rates here are among the highest in the country, and on old homes that adds up fast. Frame condition is the second — pre-1940 wood windows with rot, out-of-square openings, or lead paint often force full-frame replacement plus repair rather than a quick insert. On the product side, Washington's energy code effectively requires Northern-zone glass, so budget bids built around basic double-pane rarely reflect what will actually pass permit. The offset is durability: getting water and air management right on a century-old frame solves the condensation and rot problem that keeps recurring.
›Do I need a permit to replace Casement windows in Seattle?
Replacement generally requires a permit, and new units must meet the current energy code. See our Seattle guide for local permitting and rebate details, and always confirm your installer pulls the permit.
Sources
- — U.S. Census Bureau, American Community Survey 5-Year Estimates (B25034, B25035)
- — EPA ENERGY STAR Version 7.0 Residential Windows specification
- — DOE/PNNL IECC climate zone assignments by county
- — NREL residential window cost analysis (planning ranges)