Basement Window Replacement Cost by Window Type

Replacing a basement window in an existing opening usually costs in the hundreds of dollars, not thousands. Fixr reports a national range of $500 to $1,000, with most homeowners paying around $750 for a medium-sized prefab egress sliding window with a vinyl frame (page updated December 13, 2023) ¹. Its low end is $300 for a small fixed glass block window and its high end $7,000 for a large custom fiberglass casement egress window with a new well ¹.

What moves the price most is not the glass but the hole and what is outside it. A swap into an existing opening above ground is a small job. A new or enlarged opening means cutting the foundation, and a window below ground needs a well. Those two items are where basement window prices jump.

Price by window type

Fixr lists unit prices, before labor, for the common basement types in prefab and custom sizes ¹:

Source: Fixr, updated December 13, 2023 ¹.

Fixr puts labor at $150 to $700 per window depending on type and size: $200 to $300 for hopper and awning windows, $150 to $250 for small sliders, and $200 to $700 for egress windows ¹. Replacing only the window, materials and labor together, comes to $500 to $1,000 in Fixr's figures ¹.

Hopper windows

A hopper is hinged at the bottom and tilts in from the top. Fixr notes hoppers are common in basements because they can go in without a well, and that they are not used as egress windows because of how they open ¹. Modernize reports an installed hopper window at $250 to $750 on average, with a national average around $350 per window (page updated August 18, 2026) ². Modernize's figures are for hopper windows in general rather than basement ones only.

Sliding windows

Fixr describes sliders as popular in basements: small ones can sometimes go in without a well where the wall is tall enough, and larger ones can serve as egress when installed with a well ¹. Its $750 typical project is a medium prefab egress slider with a vinyl frame ¹. See sliding window cost for sliders elsewhere in the house.

Glass block

Glass block lets in light and, depending on the product, may or may not ventilate. Fixr says glass block basement windows are usually not operable, are often placed at the top of the wall, and are commonly combined with operable and egress windows ¹. They are the low end of Fixr's range ¹.

Egress windows

An egress window has to give a clear opening large enough to climb out of, which a small hopper or a block window does not. The rules are in egress window requirements: in the model code as Boise's building department reproduces it, at least 5.7 square feet of net clear opening and a sill no more than 44 inches above the floor (Boise handout) ³. Your locally adopted code governs. The full price of an egress project, with the well and digging, is covered in egress window cost.

When the price jumps: wells and new openings

Fixr's figures for the bigger jobs, all updated December 13, 2023 ¹:

• Replacing a window well: $750 to $1,500 in labor ¹.
• New window plus new well: $2,500 to $7,000, materials and labor ¹.
• A new window in an existing basement wall: $1,500 to $3,500 per window, or $3,000 to $7,000 with a new well ¹.
• Enlarging an opening: from $500 to $1,000, or $1,500 to $3,000 when it is enlarged to egress size with the extra excavation ¹.
• Filling in an unwanted window: from $60 to $200 per square foot ¹.

The reason is the mechanism, not the window. Cutting a concrete or block wall, digging outside, setting a well and making sure it drains is a different trade from setting a window in an existing frame. Fixr notes that larger and egress windows also need the installer to work from inside the well, which raises labor ¹.

Why the numbers may differ from your quote

These are national figures from cost surveys, and they are not a quote for your house. Fixr says its data comes from pricing databases, contractors and industry experts, without giving a sample size, and its basement page was last updated in December 2023 ¹. Modernize's hopper figure is newer but covers hopper windows anywhere in a house ². The two sources also measure different things: Fixr's table is unit price before labor, Modernize's is installed. How the cost surveys differ explains the general pattern.

Things that may move a basement quote:

• Above or below grade. Fixr notes that basement windows set entirely above ground tend to be smaller, that small hopper and awning windows are typically easier to replace, and that larger and egress windows mean working in a well ¹.
• Frame condition. Basement windows sit close to soil and water. Fixr notes many basement windows leak because of how they are installed in the foundation ¹. A rotted wood buck or frame adds work; see window frame replacement cost.
• Insert or full frame. An insert keeps the old frame; a full-frame job removes it. Full-frame vs. insert window replacement explains when each fits.
• Frame material and size. Fixr's typical project is a prefab vinyl slider, and its high end is a large custom fiberglass casement with a new well ¹. See window frame materials compared.
• Permits. A like-for-like replacement and a new opening may be treated differently by your building department; do you need a permit to replace windows covers how cities differ.

Questions to ask before you sign

• Is the price for the window only, or installed with trim, sealing and haul-away?
• Does the job need a new or replaced well, and is drainage included?
• If the window is in a bedroom, what net clear opening will the new window give?
• Is the existing frame or buck sound, or does the quote include repairing it?
• Is the installer licensed where your state licenses this work?

The window replacement cost guide covers whole-house prices, and how to compare window quotes covers what a written quote should show. When you have your list, you can compare quotes from window installers.

About these figures

• ¹ Reported: Fixr basement window replacement page: $500 to $1,000 range, $750 typical project, $300 low and $7,000 high, unit prices by type, labor by type, window-only, well, new window plus well, new opening, enlarging and filling costs, and its notes on hoppers, sliders, glass block, leaks and method, updated December 13, 2023, checked October 26, 2026.
• ² Reported: Modernize hopper window guide: $250 to $750 installed on average and a national average around $350 per window, updated August 18, 2026, checked October 26, 2026.
• ³ Official record: City of Boise IRC handout #438 (March 2022): 5.7 square foot net clear opening and 44 inch sill height, checked October 26, 2026.