Local research · updated July 2026

Double-hung windows in Dover, Delaware

Two vertically sliding sashes; both the top and bottom sash open. For Dover's mixed-age housing stock (43.5% of homes predate 1980), double-hung window replacement is a common project — and in the ENERGY STAR North-Central zone, the number that matters most is a low U-factor (≤ 0.25) to keep heat in.

Short answer

Double-hung windows in Dover typically cost $685–$3,105 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 Dover (BEA Regional Price Parity, 2024). How we estimate →

$685–$3,105

installed range per opening for Double-hung window, from a mid-grade insert up to a premium or full-frame job

Source: NREL REMDB + BLS PPI, localized to Dover

43.5%

of Dover homes were built before 1980

Source: U.S. Census Bureau, 2019–2023 ACS 5-Year Estimates

SHGC ≤ 0.4

the ENERGY STAR v7.0 number that matters most in the North-Central zone

Source: EPA ENERGY STAR v7.0

Is a Double-hung window right for a Dover home?

Both sashes slide vertically and typically tilt inward for cleaning.

Where it fits:

  • Traditional and historic home styles
  • Rooms facing walkways, porches, or patios (no outward projection)
  • Easy cleaning from inside on upper floors

What to weigh:

  • More potential air-leakage paths than hinged styles at equal quality
  • Half the opening ventilates at any one time

Double-hung windows and Dover's climate

Dover sits in the ENERGY STAR North-Central zone (IECC zone 4A (mixed, moist), Kent County), where the priority is a low U-factor (≤ 0.25) to keep heat in.

Double-hung sashes seal against weatherstripping as they slide, so they have more potential air-leakage paths than hinged styles. In the North-Central zone, prioritize a well-built unit and a low U-factor (≤ 0.25) to offset that.

New to these numbers? See our plain-English guide to U-factor and SHGC and the full double-hung guide.

What Double-hung windows cost in Dover

Double-hung window replacement in Dover runs $685–$3,105 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. Delmarva pricing is generally moderate. Old openings drive full-frame spreads. Federal 25C is gone; Energize Delaware whole-home tracks are the realistic path. Itemize every bid.

That's the national range shifted to Dover's cost level using the BEA Regional Price Parity for Dover, DE (97.5, 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 Dover

A sample of companies with locations in the Dover market. See the full Dover directory for all listings, our map, and featured-partner disclosures.

✓ Top PickPremier Partner

Renewal by Andersen Window Replacement

Renewal by Andersen4.8 · 200,000+ reviews

Showrooms in Newark, Glassboro & Greenwood · serving the Dover metro

Full-service manufacturer and installer, transferable warranty, local crews. Why it's our Top Pick

Get a quote →

1Pella Windows and Doors Showroom of Rehoboth Beach, DE

Rehoboth Beach, DE · Pella

Get matched →

2Pella Windows and Doors Showroom of Wilmington, DE

Wilmington, DE · Pella

Get matched →

3Window World of Northern Delaware

Wilmington, DE · Window World

Get matched →

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 Dover homeowners directly.

Rebates & incentives in Delaware

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.

Delaware's IRA Home Energy Rebates (HOMES whole-house efficiency and HEAR electrification) are administered by DNREC's Division of Climate, Coastal and Energy / State Energy Office. DNREC reports roughly $33M each for HOMES and HEAR; early administrative funding was approved and full applications were submitted in 2024, with a hoped-for launch in 2025 — but as of mid-2026 consumer-facing portals were not clearly open as a reliable retail path, and third-party trackers still listed both tracks as awaiting final DOE approval. Treat status as pending: windows would generally qualify only inside a whole-home HOMES modeled-savings project when live, not as a simple per-window check. Confirm current status on dnrec.delaware.gov and energizedelaware.org before promising rebate dollars. See our Dover guide for the full program list.

Double-hung windows in Dover: FAQ

›What efficiency numbers should a Double-hung window in Dover meet?

Dover sits in the ENERGY STAR North-Central zone (IECC 4A (mixed, moist)). Qualifying units need a U-factor of 0.25 or lower and an SHGC of 0.4 or lower. Double-hung sashes seal against weatherstripping as they slide, so they have more potential air-leakage paths than hinged styles. In the North-Central zone, prioritize a well-built unit and a low U-factor (≤ 0.25) to offset that.

›How much does Double-hung window replacement cost in Dover?

A useful planning range for Double-hung window replacement in Dover is $685–$3,105 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. Delmarva pricing is generally moderate. Old openings drive full-frame spreads. Federal 25C is gone; Energize Delaware whole-home tracks are the realistic path. Itemize every bid.

›Do I need a permit to replace Double-hung windows in Dover?

Replacement generally requires a permit, and new units must meet the current energy code. See our Dover 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)