Updated September 2026. Cost figures are planning estimates from named sources. How we estimate costs
What are you trying to figure out?
Estimate replacement cost
Low, typical and higher-complexity ranges for your project.
Analyze one quote
Cost per opening, what explains it, and what the quote leaves out.
Compare two quotes
Are these two contractors quoting the same job at all?
Choose a window product
Fifty window lines, by material, positioning and warranty.
Repair or replace
Fogged glass, drafts, rot and broken hardware: what each one really needs.
Browse analyzed quote threads
Public homeowner quote threads with the numbers, the scope and what was never stated.
Featured products
Vinyl
Pella 250 Series
Lifetime cover becomes ten transferable years when you sell.
Fibrex composite
Andersen 100 Series
Transfers with the house. No double-hung in the line.
Ultrex fiberglass
Marvin Essential
Terms published in one document, and no lifetime claim.
Fiberglass
Pella Impervia
Special shapes carry a different material and warranty.
Clad wood
Andersen 400 Series
Exposed wood exteriors carry only five years.
Vinyl, wood interior
ProVia Aeris
Real wood inside, with its own shorter finish warranty.
Catalog
The full window catalog
ProVia Endure, Simonton 6500 and Marvin Elevate too.
Head to head
Andersen 100 vs Pella 250
Composite against vinyl.
Andersen 100 vs Marvin Essential
Fibrex against Ultrex.
Pella 250 vs Impervia
Is the fiberglass upgrade worth it?
Andersen 100 vs 400
Composite or clad wood.
ProVia vs Simonton
Premium vinyl, two warranties.
Vinyl vs fiberglass
Cost per year of service life.
Casement vs double-hung
Which window style fits each room.
Common problems
Diagnostic guide
Fog between the panes
What a failed glass seal is, how to tell it from room-side condensation, what glass-only replacement restores and why defogging is not the same thing.
New windows drafty?
Find where the air gets in and who should fix it.
How long vinyl windows last
What wears out first, and the signs it is time to replace.
| What you notice | Try first | Replace when |
|---|---|---|
| Fog between the panes | Replace the sealed glass unit | Seals are failing on many windows |
| Drafts around a working window | Weatherstripping and caulking | Frames are warped or rotted |
| Sash will not stay open | Replace balances, cranks or locks | Several windows have multiple failures |
| Soft or rotted frame or sill | Limited repair if the damage is small | Rot is widespread: full-frame replacement |
| Single-pane in a hot or cold climate | Storm windows as a cheaper step | You plan to stay for many years |
Full decision guide: Repair vs replace windows — symptom matrix, cost thresholds and when glass-only beats a full unit.
Buying, quotes and installation
Why quotes vary so much
Ten factors behind an $8,500 gap on the same twelve windows.
What a quote should include
Line-item checklist, plus the federal three-day cancellation right.
How to compare quotes
Cost per opening and the eight specifications that must match.
Insert vs full-frame
The installation decision that moves a quote most.
How long replacement takes
Install day versus the order wait, and which dates to get in writing.
Window replacement cost
Per window, by material, and for the whole house.
Are new windows worth it?
Resale data and break-even math.
Warranty decoder
What lifetime, glass, labor and transferable actually mean.
ProVia warranty
Which card covers your windows or doors, and how transfers work.
Milgard Tuscany quote decoder
What a V400 quote has to state before you compare it.
Energy and performance
Two things decide it, and neither is the brand on the sticker.
The glass package
Low-E coating, pane count and gas fill drive the U-factor and SHGC printed on the NFRC label. It is the only figure worth comparing between quotes.
Climate zone
ENERGY STAR certification is set by zone, so a window certified in Florida is not automatically certified in Minnesota.
Not the line name
None of the manufacturers in our catalog publishes a single U-factor range for a whole line. Ask for the label of the exact unit quoted.
Incentives in 2026
The federal Section 25C credit does not apply to windows placed in service after December 31, 2025 (IRS). State and utility rebates remain. See the 25C / QMID decoder for 2025 install paperwork.
Triple vs double pane
When the extra glass is worth it — compare NFRC U-factor and SHGC by climate, noise and budget. No universal winner.
How to read the NFRC label
U-factor, SHGC, VT and air leakage decoded — the numbers to demand so two window quotes are actually comparable.
NFRC Label Decoder
Type in the label figures and see U-factor, SHGC, VT and air leakage checked against your climate zone.
Argon vs krypton gas fill
When the gas fill is worth it — cavity width decides more than the buzzword; compare NFRC U-factor deltas on the quote.
Public quote threads, analyzed
Public forum thread · 14 openings
$46,000 from one brand, $25,000 from another
About $3,290 per opening against about $1,790, and neither quote stated its installation method.
Submit your quote
Anonymous, no personal details asked.
All cases
With the original source linked on every one.
New on UpgradeWorth: roof replacement guides. What actually drives the price, what a written bid has to spell out, and how roofing warranties really work.
Cost figures are planning estimates, not quotes. Get written local quotes before committing. Related: Doors.