Local research · updated July 2026
Replacement Windows in Knoxville, Tennessee
Knoxville's windows are old even by the standards of an old-housing-stock region. Nearly six in ten of the city's homes — 59.4% — were built before 1980, and the median year built is 1974, which means the typical Knoxville house went up before double-pane glass was standard practice anywhere in Tennessee. The stock runs from Victorian and craftsman sash in Fourth & Gill and Old North Knoxville to postwar ranches with single-pane aluminum sliders across Fountain City and West Hills. Layer on a true four-season valley climate — humid 90-degree summers, real winter freezes, and air that stagnates between the Smokies and the Cumberland Plateau — and window choices here have to work in both directions, not just one.
Short answer
In Knoxville, a standard replacement window (double-hung, casement or slider) typically costs $520–$2,950 installed. Bay and bow windows run $2,595–$8,290+, and a sliding patio door $1,555–$5,180. 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 Knoxville with the BEA Regional Price Parity for Knoxville, TN (2024). How we estimate →
59.4%
of Knoxville 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
1974
median year built across Knoxville's 94,885 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 Knoxville
Compare companies serving Knoxville. 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 | Knoxville, TN | Get a quote → |
| 1Champion Replacement Windows of KnoxvilleChampion | Knoxville, TN | Get matched → |
| 2Pella Windows and Doors Showroom of Knoxville, TNPella | Knoxville, TN | Get matched → |
| 3Window World of KnoxvilleWindow World | Knoxville, TN | Get matched → |
Renewal by Andersen of Knoxville
4.8 · 200,000+ reviewsKnoxville, TN showroom · serving the Knoxville metro
Full-service manufacturer and installer, transferable warranty, local crews. Why it's our Top Pick
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What drives window decisions in Knoxville
- With a median year built of 1974 and 59.4% of homes predating 1980, most Knoxville replacement projects start from single-pane wood sash or first-generation aluminum — big efficiency gaps, but also, in the older neighborhoods, original woodwork that's often worth repairing instead of discarding.
- Knox County sits in IECC Climate Zone 4A — mixed and moist — where heating and cooling loads are roughly balanced, so both U-factor (winter) and solar heat gain coefficient (summer) genuinely matter; single-metric sales pitches undersell half the year.
- The City of Knoxville enforces the 2018 International Energy Conservation Code, a meaningfully stricter baseline than Tennessee's statewide floor, which still rests on the 2009 IECC that local governments can amend or opt out of.
- H-1 historic overlay districts — Fourth & Gill and Old North Knoxville chief among them — require a Certificate of Appropriateness from the Knoxville Historic Zoning Commission before visible window changes, and the adopted design guidelines explicitly favor repairing original sash over replacement.
Replacement windows & doors by type in Knoxville
Local cost ranges and North-Central-zone efficiency guidance for each window and door style, specific to Knoxville homes:
Ranges localized to Knoxville's cost level: national planning ranges shifted by the BEA Regional Price Parity for Knoxville, TN (92.6, U.S. = 100; 2024). How we estimate local costs →
Efficiency requirements for Knoxville's climate
Knoxville sits in the ENERGY STAR North-Central zone (IECC zone 4A (mixed, moist), Knox 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
Knoxville window pricing tends to land below what national averages suggest, because labor costs in East Tennessee run under those of coastal metros — but the age of the stock pushes many projects toward the expensive end of the local range anyway. An insert replacement in a 1970s Cedar Bluff or Halls ranch with sound frames is the simple case. Full-frame work in a pre-1940 Fourth & Gill or Old North Knoxville house costs meaningfully more: rot repair in a humid climate, weight-pocket insulation, out-of-square openings, and custom sizing all add labor, and if the house sits in an H-1 overlay, the Historic Zoning Commission may require wood or approved wood-composite units that cost well above vinyl. The valley's humidity also makes flashing and installation quality matter more than brand — a mid-tier window installed carefully beats a premium unit installed badly here. Get itemized quotes and be wary of single-number pricing after a long in-home pitch.
For a breakdown by frame material and install type, see our full cost guide.
Rebates & incentives in Tennessee
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.
Tennessee's IRA Home Energy Rebates are administered by TDEC's Office of Energy Programs (the state energy office); the state's allocation was approved but the consumer-facing HOMES/HEAR programs had not launched as of mid-2026. Check TDEC for current status before promising rebates.
- TVA EnergyRight Home Energy Rebates. TVA's valley-wide EnergyRight program offers residential rebates that explicitly include windows alongside insulation, air sealing, and HVAC; work must be done by a contractor in TVA's Quality Contractor Network, who submits the rebate for you. (TVA EnergyRight (energyright.com))
- Local power company programs (NES, MLGW, EPB, and co-ops). TVA distributes EnergyRight through local power companies — Nashville Electric Service, Memphis Light Gas & Water, Chattanooga's EPB, Middle Tennessee Electric and others — so rebate availability and amounts vary by utility; confirm with your local power company. (NES, MLGW, EPB, MTE program pages)
Tennessee's statewide residential energy code is still based on the 2009 IECC with state amendments, though some cities such as Nashville enforce newer editions — check local requirements for replacement window U-factors.
Replacement windows in nearby metros
Not in Knoxville proper? These nearby markets carry the same local research: housing-age data, climate-zone specs, and current rebate status for each city:
Knoxville window replacement FAQ
›Do I need a permit to replace windows in Knoxville?
For a like-for-like swap — same opening, same size, no structural changes — the City of Knoxville generally treats window replacement as repair-level work, though the city's Plans Review & Inspections division is the authority and a quick call settles your specific case. A permit is required if you're enlarging or adding an opening, altering structure, or changing an emergency-escape window in a way that shrinks the clear opening below code minimums. Outside the city limits, Knox County Codes Administration and Enforcement handles permitting separately. The important exception is historic zoning: in an H-1 overlay like Fourth & Gill or Old North Knoxville, a Certificate of Appropriateness from the Knoxville Historic Zoning Commission is required before any visible window change, regardless of whether a building permit is.
›What efficiency numbers should replacement windows meet in Knoxville's climate?
Knox County falls in IECC Climate Zone 4A and the ENERGY STAR North-Central zone. Under the ENERGY STAR Version 7.0 specification for this zone, windows need a U-factor of 0.25 or lower and a solar heat gain coefficient of 0.40 or lower. The city's adopted energy code, based on the 2018 IECC, sets a less demanding floor, so ENERGY STAR-rated units clear code comfortably. Unlike the Deep South, where SHGC dominates, or the upper Midwest, where U-factor does, Knoxville's heating and cooling seasons are close to balanced — so insist on seeing both numbers on the NFRC label of the actual glass package being quoted, not the product line's best-case brochure figures.
›Are there rebates or assistance programs for windows in Knoxville right now?
The federal 25C Energy Efficient Home Improvement Credit — up to $600 per year for qualifying windows — expired on December 31, 2025, and as of mid-2026 has not been renewed. Locally, TVA EnergyRight runs efficiency rebates through KUB, the Knoxville Utilities Board, with windows among eligible measures; rebates route through installers in TVA's Quality Contractor Network, so ask any bidder whether they're QCN members before signing. Income-qualified KUB customers should look at Home Uplift, the TVA EnergyRight partnership into which KUB puts $1 million a year: it delivers an average of roughly $12,000 in no-cost weatherization per home — typically air sealing, insulation, and HVAC, with window work possible where it's the right fix. Tennessee's federally funded HOMES rebate program had not launched as of this writing.
›My house is in Fourth & Gill or Old North Knoxville — should I restore my original windows instead of replacing them?
Often yes, and in an H-1 district it may be the path of least resistance anyway. The adopted design guidelines direct the Historic Zoning Commission to favor repair of original sash, and any approved replacement must match the original's size, pane division, muntin profile, and exterior depth — which usually rules out off-the-shelf vinyl. The honest performance math helps the preservation case: a restored wood sash with new weatherstripping plus a good storm window achieves overall thermal performance in the neighborhood of a mid-grade double-pane replacement, and hundred-year-old old-growth wood frames outlast modern vinyl. Restoration is labor-intensive and Knoxville has a limited pool of sash specialists, so get quotes for both routes — but get the Certificate of Appropriateness question answered before you sign anything.
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
- — Asthma and Allergy Foundation of America; American Lung Association
- — IRS, 25C Energy Efficient Home Improvement Credit (P.L. 119-21)