Window sash replacement swaps only the moving parts of the window, the framed panels that hold the glass, and keeps your existing frame and trim. HomeGuide puts it at $200 to $600 per window, against $450 to $1,500 for a new single hung window installed.
If the frame is solid, square and dry, a new sash is usually the smarter spend. If the frame is rotted, out of square or leaking, you’re paying to put new parts into a failing box, and a full replacement makes more sense.
At TurnKey Window we’ll check the frame first and give you both options when both are on the table. Request a free consultation or call (504) 226-6201, and read on for how to weigh the two.
Key takeaways
- A sash is the framed part of the window that holds the glass. Sash replacement leaves the frame and trim in place.
- HomeGuide puts sash replacement at $200 to $600 per window and a full single hung replacement at $450 to $1,500.
- Sash replacement kits for double hung windows include new sashes and new jamb liners that snap into the old frame.
- A rotted, warped or out of square frame rules out a sash only fix.
- In homes built before 1978, work that disturbs painted surfaces calls for an EPA or state certified firm.
What a window sash is
HomeGuide defines the sash as the framed part of a window that holds the glass. On a double hung window both sashes slide, and on a single hung window only the lower one moves.
When you replace a sash, HomeGuide notes, the perimeter framing and the sealed glass inside it are replaced as one assembly. The frame, sill and trim around it stay put, which is why the job is quicker and less disruptive than a full tear out.
Three ways to deal with worn sashes
This Old House lays out three options for a double hung window with sashes past saving.
- Sash replacement kit. New sashes and jamb liners fit into the existing frame. This Old House calls it the least expensive option when the rest of the window is in good condition.
- Frame and sash unit. Sometimes called a boxed unit, this adds a new frame that sits inside the old opening.
- Full window replacement. The whole window comes out and a new one goes in. This Old House calls it the most costly and invasive route.
Cost comparison
HomeGuide’s sash and window replacement cost guides let you compare the two directly. The sash numbers include materials and labor.
| Option | HomeGuide cost range | Notes |
|---|---|---|
| Single hung sash | $200 to $500 | Simplest design with fewer moving parts |
| Double hung sash | $250 to $600 | Two operating sashes and more hardware |
| Casement sash | $250 to $800 and up | Heavier sash that needs sturdy hinges and precise alignment |
| New single hung window | $450 to $1,500 | Average installed cost per window |
| New double hung window | $350 to $2,500 | Installed, per unit |
How material changes the sash price
- Vinyl sash: $200 to $500 installed, the least expensive.
- Fiberglass or composite sash: $250 to $600 installed.
- Wood sash: $300 to $800 installed, the most expensive and common in historic homes.
HomeGuide adds that labor runs $50 to $150 per window for simple, easy access jobs and $100 to $200 for fitting sashes into older wood frames. Jobs that need repairs or removal of damaged material can hit $300 or more per window.
When sash replacement is the right call
Sash replacement shines when the window’s problems are in the parts that move. HomeGuide lists the signs that point to a new sash.
- The window is hard to open or close.
- The sash itself is rotted, warped or cracked.
- Fog or condensation shows between the panes.
- You notice drafts or water leaking indoors.
- Energy bills are up with no other explanation.
It also makes sense when you want to keep what’s around the window. This Old House points out that a kit lets you keep the existing frame and your home’s original look while upgrading the moving parts, and there’s no need to disturb interior or exterior trim.
Not every draft needs a new sash, though. HomeGuide notes some leaks only need caulking or new gasket material, at about $75 to $150 per window.
When a full replacement makes more sense
The frame is the deciding factor. This Old House’s install steps include checking the frame for rot or damage, confirming the sill and head jamb are level, and making sure the side jambs are plumb before a kit goes in.
If the frame fails those checks, a new sash will bind, leak or sit crooked. HomeGuide puts window frame replacement at $200 to $600 for standard windows and up to $1,200 for specialty windows, and by then a full window often costs little more.
- Soft or rotted frame wood that a screwdriver sinks into.
- A frame out of square, where the sashes have gaps on one side and bind on the other.
- Water damage around the opening, such as stained drywall or soft siding below the sill.
- A change in size or style, since a sash has to match the frame you have.
Our window replacement service covers full swaps when the frame is past repair.
How a sash replacement kit goes in
This Old House walks through the install on a traditional double hung window. It helps to know the steps, even if you hire the job out.
- Measure the frame. Width between the side jambs, and height from the sill to the head jamb, then order to the maker’s instructions.
- Remove the stops and old sashes. Score any caulk first so the stops come off intact for reuse. Cut sash cords or chains and let the weights drop into the pocket.
- Pull the parting bead and pulleys. The parting bead that separates the sashes can be discarded.
- Inspect and repair the frame. Fix rot and confirm level and plumb.
- Install the jamb liners. They give the new sashes a smooth track and hold the balance system.
- Set the upper and lower sashes. Each tilts in, engages the balance and slides into place.
- Reinstall the stops and test. Open, close and lock both sashes several times and adjust as needed.
This Old House also suggests filling the empty weight pockets with insulation, such as low expanding spray foam, while the window is open. It’s a small extra step that closes a drafty cavity.
Safety on older windows
Old sash windows are often painted many times over. The EPA’s Renovation, Repair and Painting rule requires firms doing work that disturbs lead based paint in homes built before 1978 to be EPA or state certified and to follow lead safe work practices.
If your house predates 1978, hire a certified firm for sash work rather than scraping and prying yourself. Heavy upper sashes and second story windows are also a two person job, so keep ladder work to professionals.
Other things to weigh
Price isn’t the only difference. A few practical points often tip the decision.
- Glass upgrades. HomeGuide notes double or triple glazing, low E coatings and gas fills raise the sash price, and they come with either option.
- Historic character. Keeping original frames and trim preserves the look of an older home, which a kit is designed to do.
- Permits. HomeGuide says same size, same type window replacement typically doesn’t need a permit, while changing the size needs one for reframing. Check with your local permit office for your address.
- Maintenance. This Old House recommends keeping tracks clean and checking weatherstripping so a new sash keeps sealing tight.
For double hung styles specifically, our double hung windows page covers the options. Sash and frame repairs are covered on our window repair page.
Sash or full replacement at a glance
Here’s the whole comparison on one screen, pulled from the sources above. Use it as a checklist when you walk around the house.
| Question | Sash replacement | Full replacement |
|---|---|---|
| What gets replaced | Sashes, glass and, with a kit, jamb liners | Frame, sashes and glass |
| Trim and interior finishes | Left in place | Often disturbed, depending on install method |
| Frame condition needed | Sound, level and plumb | Any, since the frame is new |
| Typical cost per window | $200 to $600 | $450 to $1,500 for a single hung window |
| Size or style change | Not possible | Possible, with reframing |
If you’d answer “sound” for the frame on most of your windows, get a sash quote first. If most frames are soft, skip straight to replacement quotes.
What to get in writing on a quote
Sash and full replacement quotes can look alike on paper while covering very different work. HomeGuide suggests a few things every estimate should spell out.
- Sash cost, labor, materials and any disposal or extra fees, each listed separately.
- The product, the sash material and the brand being installed.
- Whether parts and labor carry a warranty, and for how long.
- Projected start and finish dates, plus the deposit and payment schedule.
HomeGuide also recommends hiring only licensed and insured contractors. Put two quotes side by side, one for sashes and one for full replacement, and the price gap will tell you how much the frame is worth saving.
Frequently asked questions
Can you replace just the window sash?
Yes, if the frame is in good condition. HomeGuide says replacing only the sash is less expensive and less disruptive, and a kit fits into the existing frame without disturbing the trim.
How much does window sash replacement cost?
HomeGuide puts it at $200 to $600 per window, with sash materials at $150 to $400 and labor at $50 to $200 for most projects. Wood sashes run highest, at $300 to $800 installed.
Is sash replacement cheaper than a new window?
Usually. HomeGuide’s sash range of $200 to $600 compares with $450 to $1,500 for a new single hung window installed, though a damaged frame can erase that savings.
What is included in a sash replacement kit?
This Old House lists two jamb liners and two new sashes for a double hung window. The liners snap into clips on the old frame and carry the balance system for the new sashes.
Can you replace the sash on a casement window?
Yes. HomeGuide lists casement sash replacement at $250 to $800 or more, higher than hung windows because the sash is heavier and needs sturdy hinges and precise alignment.
Find out what your windows need
The frame tells you which way to go, and it takes a hands on look to know. Contact TurnKey Window for a free consultation or call (504) 226-6201, and we’ll tell you whether new sashes will do the job.