How to Compare Three Window Quotes Line by Line

Window quotes are unusually hard to compare because so much of what drives the price is invisible on the page. The window is the part everyone looks at, and it is often the part that differs least.

Here is the list to rebuild all three quotes onto.

1. Installation method

The single largest source of difference. A retrofit installs into the existing frame; the exterior is not disturbed and the work is largely interior. A full-frame replacement removes the frame back to the rough opening, which means exterior cladding and flashing work at every window.

These are different jobs at different prices. If one quote assumes retrofit and another full-frame, stop comparing until you know which your house actually needs — retrofit versus new construction windows covers how that is determined.

2. The window, by its numbers

Ask for the NFRC certified figures for the exact product and configuration. Compare U-factor and SHGC across the three quotes. A brand name is not a specification — manufacturers make entry-level and premium lines and both carry the same badge.

Check the numbers against the requirement for your climate zone while you are there; see what Title 24 requires of your new windows.

3. The opening count and schedule

Sounds obvious, and quotes still differ on it. Confirm each quote covers the same windows, in the same sizes and operating styles. Fixed versus operable, and a slider versus a casement, are different prices for the same hole.

4. Interior finish

What happens to the stool, apron, casing and paint. Full-frame work disturbs all of it; retrofit disturbs some. This is the most common silent exclusion and the one homeowners notice most, because it is the part they look at every day afterwards.

5. Exterior finish

On full-frame work, the cladding around the opening comes off and has to go back. Ask specifically how the exterior is made good, and to what standard — this is where matching problems on stucco and older siding show up.

6. Rot and repair

Nobody knows what is in the frame until the old window is out. Ask each contractor for a unit rate per opening for defined repair work, rather than a fixed sum or nothing at all. Then a discovery has an agreed price instead of becoming a negotiation halfway through.

7. Permit and disposal

Both real, both frequently excluded, both easy to check.

8. The two warranties

Separate them. The manufacturer warrants the product; the contractor warrants the installation. Ask how long each runs, what each covers, and whether either transfers on sale. Most early failures are installation-related, so the labour warranty usually matters more than the headline number on the product.

9. Timeline and payment

Lead time on the windows, days on site, and the payment schedule. A large deposit relative to the job is worth asking about — in California there are limits on what a contractor may take up front, and a request well outside the norm is a signal.

Putting it together

Write the nine items down the side of a page and the three quotes across the top. Most of the difference will resolve into two or three cells, and those cells are the actual decision — not the total at the bottom.

For a sense of whether all three are in a normal range, our Northern California window replacement cost page publishes installed per-window ranges with the date and basis stated. Use it to spot an outlier rather than to argue a number.

The same discipline applied to siding is in how to compare siding quotes.

Working with Heritage Exteriors

We quote windows with the method, the certified figures, the exclusions and the repair unit rates written down, so our quote can be compared line by line against anyone else's. Licensed in California, CSLB #1055919. Call (916) 546-2991.