Basement window replacement cost: hopper, slider or egress

Replacing a basement window in the same opening usually costs about $300 to $900 in 2026 for a standard hopper or slider, installed. An egress window that you can climb out of in a fire is a much bigger job: verified project data from Angi puts it at about $2,700 to $5,900, with a national average around $4,200, because the opening usually has to be cut larger and a window well dug outside. Which one you need depends on how the basement is used.

Douglassville areaSep 2025

The numbers

These ranges come from 2026 cost guides, with egress figures from Angi's verified projects. Poured concrete walls cost more to cut than block walls, and deep wells cost more to dig and drain.

Hopper, slider or casement

Hopper windows are hinged at the bottom and tip in at the top. They are the most common basement window. They vent well and are cheap, but they cannot serve as egress, because the open sash blocks the opening.

Sliders move side to side. They give a larger clear opening than a hopper of the same size and can sometimes meet egress rules if the opening is big enough.

Casements crank out and open fully. They give the largest clear opening for their size and are the usual choice for egress.

When you need egress

Under the residential code Pennsylvania uses, any basement with a habitable space, and every sleeping room in it, needs an emergency escape and rescue opening. In plain terms, an egress window needs:

• A net clear opening of at least about 5.7 square feet (5 square feet is allowed for some grade-floor openings).
• A clear opening at least 24 inches high and 20 inches wide.
• A sill no higher than 44 inches above the floor.
• A window well outside, if the window is below grade, with enough room to climb out, and a ladder or steps if it is deeper than 44 inches.

If you are finishing a basement as a bedroom, playroom or office, plan on at least one egress window. Your township code official makes the final decision.

Why egress costs so much more

An egress window is less about the window and more about the hole:

1. Cutting the foundation. A saw cuts a larger opening in the concrete or block wall. Poured concrete needs a wet saw and a lot of care.
2. A header or lintel if the opening is wider than the old one, to carry the wall above.
3. Excavation outside for the well, often by hand near the house.
4. A window well of steel, plastic or stone, with drainage at the bottom, often tied into the footing drain or a gravel bed.
5. The window, usually a casement or large slider.
6. Interior finish: framing, drywall return, trim and sometimes moving pipes or ducts.
7. A permit and inspection.

Replacing old basement windows

Many basements in our area still have old steel windows rusted into the foundation, or wood windows that rotted where they sit on the concrete. Replacement involves:

• Removing the old frame, which can mean cutting rusted steel out of the concrete.
• Cleaning up the opening and repairing the concrete or block edges.
• Setting a new vinyl window on a treated wood buck or directly into the masonry opening.
• Sealing the joint to the foundation with a flexible sealant or mortar patch.
• Trimming inside if the basement is finished.

Like any window in masonry, every opening is measured on its own. On the brick house in the Douglassville area, each new window was fitted to its own masonry opening and sealed to the brick, which is the same approach we take below grade.

Window wells and drainage

A window below ground needs a well, and the well needs to drain. Leaves and snow in a well that does not drain mean water against the window and, sooner or later, in the basement. Good practice:

• Gravel at the bottom of the well, connected to a drain if possible.
• The well a few inches above grade so surface water does not pour in.
• A clear cover that keeps out leaves and snow but can be opened from inside for egress.
• Grading that slopes away from the well.

Glass block and security

Glass block windows let in light, resist break-ins and need little care. They do not open unless a small vent is built in, and they cannot be egress. They suit laundry rooms and unfinished storage areas.

If security is a concern, look for strong locks, laminated glass, or bars with a quick release on the inside where egress is needed.

Energy and moisture

Old basement windows are often the leakiest openings in a house. New insulated windows with good sealing reduce drafts and help control humidity. Condensation on basement windows usually means high humidity, which a dehumidifier helps with more than any window can.

Our part of the work

We are carpenters. We replace basement windows in existing openings, set bucks, seal and trim them. For cutting a new egress opening in a poured foundation and digging a deep well, we work with concrete cutting and excavation contractors we know, and coordinate the job and the permit. We tell you who is doing what before we start.

Permits and contracts in Pennsylvania

Replacing a basement window in the same opening generally does not need a permit. Cutting a new or larger opening in a foundation wall, and adding egress for a habitable basement, does. Home improvement contracts over $500 must be in writing in Pennsylvania, you have three business days to cancel, and on larger jobs the deposit is limited to one third plus special-order materials.

Ways to save

• Replace in the same opening wherever egress is not needed.
• Use stock sizes if the opening can be adjusted slightly with a buck.
• Do all basement windows at once, since setup is the same.
• Plan egress during a basement finish, not after, so walls and trim are done once.

Common basement window problems

Most calls about basement windows come down to a few problems:

• Rusted steel frames that no longer close and let in water and cold air.
• Rotted wood frames sitting directly on the concrete.
• Windows below grade with no well, so soil and water push against the glass.
• Wells that fill with water because there is no drain at the bottom.
• Cracked or broken glass in old single-pane units.
• Condensation and mold around the frame from high basement humidity.

Each of these has a fix, and most of them start with a new window set and sealed properly in a clean opening. If water is coming in at a window, we look at the grade and the well as well as the window, because a new window in a flooded well will still leak.

Finishing around a basement window

In a finished basement, the window needs an interior return: the drywall or trim that wraps from the wall face back to the window. Concrete and block walls are thick, so these returns are deep. A clean drywall return with corner bead, or a wood jamb extension with casing, makes a basement window look like a window in any other room. A deep sill board at the bottom gives a small shelf and covers the top of the foundation. Plan the return when the walls are framed, so the window and the wall finish meet cleanly.

Questions people ask about basement windows

Can a hopper window be an egress window? No. A hopper's sash blocks the opening when open, so it does not provide a clear escape.

Do I need an egress window in my basement? If the basement has a bedroom, or is being finished as living space, yes, at least one. An unfinished storage basement usually does not.

How long does it take to install an egress window? Usually one to three days, including cutting, digging, the well and the window, plus time for the permit and inspection.

Can basement windows be replaced in winter? Yes. Same-opening replacements are quick. Egress digging is easier when the ground is not frozen.

Is the estimate free? Yes. We check the openings, the walls and the grade outside and send a written estimate.

See our window replacement service, our window replacement cost guide for Pennsylvania and the attic conversion cost guide, which covers egress for upper floors.

Ask us about your basement windows