Local research · updated July 2026
Replacement Windows in Dover, Delaware
Dover is Delaware's capital on the Delmarva coastal plain — flat terrain, humid summers, nor'easters and coastal storms, Dover AFB, and a mix of older neighborhoods and newer growth. About 43.5% of homes predate 1980 and the median year built is 1985. Kent County is ENERGY STAR North-Central / IECC 4A: both U-factor and a moderate SHGC matter. This is Delaware's first metro on the site. Replacement here is Mid-Atlantic four-season glass — not deep-South cooling-only packages.
Short answer
In Dover, a standard replacement window (double-hung, casement or slider) typically costs $545–$3,105 installed. Bay and bow windows run $2,730–$8,730+, and a sliding patio door $1,640–$5,455. Frame material and the glass package decide where a project lands in that range.
Planning ranges built from NREL and BLS cost data, localized to Dover with the BEA Regional Price Parity for Dover, DE (2024). How we estimate →
43.5%
of Dover homes were built before 1980, the era of single-pane and early aluminum windows
Source: U.S. Census Bureau, 2019–2023 ACS 5-Year Estimates
1985
median year built across Dover's 16,659 housing units
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
Window installers in Dover
Compare companies serving Dover. Request a free, no-obligation quote and we route it to the company or a vetted local installer.
| Company | Location | Request a quote |
|---|---|---|
 4.8 · 200,000+ reviews | Greenwood, DE | Get a quote → |
| 1Pella Windows and Doors Showroom of Rehoboth Beach, DEPella | Rehoboth Beach, DE | Get matched → |
| 2Pella Windows and Doors Showroom of Wilmington, DEPella | Wilmington, DE | Get matched → |
| 3Window World of Northern DelawareWindow World | Wilmington, DE | Get matched → |
Renewal by Andersen Window Replacement
4.8 · 200,000+ reviewsShowrooms in Greenwood, Newark & Glassboro · serving the Dover 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 Dover homeowners directly.
What drives window decisions in Dover
- North-Central / 4A: U ≤ 0.25, SHGC ≤ 0.40 under ENERGY STAR v7.0.
- Capital + AFB market: mixed older stock and base-adjacent growth.
- Nor'easters and coastal storms stress openings; humidity cycles IG seals.
- Energize Delaware whole-home pathways; 25C expired Dec 31, 2025.
Replacement windows & doors by type in Dover
Local cost ranges and North-Central-zone efficiency guidance for each window and door style, specific to Dover homes:
Ranges localized to Dover's cost level: national planning ranges shifted by the BEA Regional Price Parity for Dover, DE (97.5, U.S. = 100; 2024). How we estimate local costs →
Efficiency requirements for Dover's climate
Dover sits in the ENERGY STAR North-Central zone (IECC zone 4A (mixed, moist), Kent County). Under the v7.0 specification, qualifying windows need a U-factor of 0.25 or lower and an SHGC of 0.4 or lower. Mixed climate: good insulation matters most, with a moderate cap on solar gain so summer cooling costs stay in check.
Not sure what these numbers mean? Read our plain-English guide to U-factor and SHGC.
What replacement windows cost here
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.
For a breakdown by frame material and install type, see our full cost guide.
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.
- Energize Delaware Home Performance with ENERGY STAR. Energize Delaware (the Delaware Sustainable Energy Utility) runs Home Performance with ENERGY STAR and related residential efficiency pathways: a whole-home audit approach that can include envelope measures (air sealing, insulation, and sometimes windows) as part of a package rather than a reliable standalone per-window retail rebate. Incentive levels and eligible measures change — verify current terms, any temporary bonus offers, and whether windows are on the measure list for your project at energizedelaware.org before counting on a window check. (Energize Delaware (energizedelaware.org); Delaware SEU)
- DNREC weatherization / income-qualified pathways. DNREC and partner agencies administer weatherization and low- to moderate-income efficiency assistance that can include envelope work for qualifying households. These are audit- and income-driven, not open retail window rebates. Confirm eligibility and current scope with DNREC Climate, Coastal and Energy. (DNREC Division of Climate, Coastal and Energy weatherization pages)
Delaware enforces a statewide residential energy code in the recent IECC family (confirm the exact edition with your local building official — the state has been on a late-2010s / 2018-era path with updates). Dover and Kent County sit in IECC climate zone 4A (mixed, moist); ENERGY STAR North-Central targets for replacement windows are a U-factor of 0.25 or lower and an SHGC of 0.40 or lower under Version 7.0.
Replacement windows in nearby metros
Not in Dover proper? These nearby markets carry the same local research: housing-age data, climate-zone specs, and current rebate status for each city:
Dover window replacement FAQ
›Do I need a permit to replace windows in Dover?
Usually yes for full replacement. City of Dover Building Inspections or Kent County for unincorporated addresses. Confirm the installer pulls the permit.
›What efficiency numbers should windows hit?
ENERGY STAR North-Central and IECC 4A: U-factor 0.25 or lower and SHGC 0.40 or lower. Read the NFRC label.
›Are there rebates?
Federal 25C expired December 31, 2025. Check Energize Delaware Home Performance with ENERGY STAR and DNREC IRA status — windows are usually whole-home measures, not simple per-window checks.
›Restore original sash or replace?
Sound wood plus storms can work. Full replacement when sashes are rotted or seals have failed systemically. Assess frame and sill condition first.
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
- — NWS Mount Holly; FEMA flood maps; Delaware energy code materials
- — IRS, 25C Energy Efficient Home Improvement Credit (P.L. 119-21)