Window Sash Replacement Only — New Sashes, Keep the Frame
The sashes are rotted, fogged or will not stay up, but the frame is solid and the trim is original. You do not want the whole window torn out.
Window sash replacement only, instead of a whole window, keeps the frame, trim and wall and swaps the moving parts. JMB Builders installs the maker's sash kits or custom sashes in sound frames across the Twin Cities, and tells you when an insert or full-frame window is the better call. Priced per window, quoted from photos within one business day.
- Priced per window
- Maker's sash kits or custom sashes
- Frame, trim and wall stay
- Licensed MN contractor BC809005
A window is a frame and the sashes that move in it. When the frame is sound, square and dry, and the problem is the sashes (rotted rails, failed glass, broken balances), replacing only the sashes keeps the original frame, the interior trim, the siding and the paint untouched. It is the least disruptive way to get working windows.
There are two ways to get sashes. Many makers, Andersen, Marvin, Pella and others, sell replacement sashes or sash kits for their own windows, ordered from the label or the frame dimensions. Kits for double hungs often include new jamb liners so the sashes tilt in for cleaning. For old site-built wood windows with no maker, a millwork shop can build sashes to size, and they are fitted to the frame.
Sash replacement is not always the answer. A frame that is rotted at the sill, out of square, or leaking around the outside needs an insert or a full-frame window. We look at the frame first, from your photos and then in person, and we tell you straight which one fits.
What you supply
- Photos of each window inside and out, open and closed
- The label on the frame or glass spacer if there is one
- Sash kits you already ordered, if you did
- Paint or stain color for new wood sashes
What JMB supplies
- A check of each frame for rot, square and leaks before anything is ordered
- Measurement for the maker's sash kit or for custom sashes
- Old sashes, stops, balances and liners removed
- New jamb liners, balances and sashes installed and adjusted
- Stops reset, locks aligned and weatherstrip checked so the sashes seal
- Painting or staining of wood sashes quoted as a separate line
How it is priced: per window
Quoted in writing from your photos within one business day. What moves the number:
- Maker's sash kit vs. custom-built sashes
- Window type: double hung, casement or slider
- Frame repair needed before the sashes go in
- Glass makeup and grille pattern
- Paint or stain on new wood sashes
- Number of windows in one visit
Send a photo of the label and of each frame's sill from outside. The sill tells us whether a sash swap will hold up.
How long it takes
Sash kits install in about an hour or two per window once they are here. Custom sashes take longer to make; fitting is part of a day per few windows.
How your project works
- 1
Send photos, get a written quote
Send three photos of the space and a sentence about what you want. You get a clear, itemized quote within one business day. We only come out to measure first when the job needs a tape measure — no pressure, no games.
- 2
Pick materials, or bring your own
We help you choose profiles and materials that fit the house and the budget, or match your existing millwork exactly — or you buy the door or trim yourself and we install it. Everything is confirmed before the crew is scheduled.
- 3
Clean, precise installation
The crew shows up on time, protects floors and furniture, and installs with tight joints and consistent reveals. Photos of the finished work go in your job folder.
- 4
Walkthrough and invoice
We walk the finished work with you. If anything is not right, we fix it before we call the job done. Then one invoice, paid by check or direct deposit — no card fees, no payment links.
Window Sash Replacement Only — New Sashes, Keep the Frame: questions, answered
Can I replace just the window sash instead of the whole window?
Yes, when the frame is sound. Sash replacement keeps the frame, trim and wall and swaps the moving parts. If the frame is rotted, out of square or leaking, an insert or full-frame window is the better fix.
Is sash replacement cheaper than a new window?
Usually less work, because the trim, siding and wall are not touched. The sashes themselves can cost as much as a basic window, especially custom wood ones. We quote both when it is close so you can compare.
Where do I get replacement sashes for my windows?
From the window's maker, when they still support it. Andersen, Marvin, Pella and others sell sashes or kits by the label or frame size. For old windows with no maker, a millwork shop builds sashes to size.
What is a sash replacement kit?
A set of new sashes, and usually new jamb liners and balances, made to go into an existing double-hung frame. The old sashes and stops come out, the liners go in, and the new sashes tilt in for cleaning.
When is sash replacement a bad idea?
When the frame is the problem: a rotted sill, a frame out of square, water coming in around the outside, or a window whose maker no longer supports it. New sashes in a bad frame still leak and bind.
Do you replace casement sashes too?
Yes. Casement sashes are replaced with the maker's part, hung on the existing hinges or new ones, with the operator adjusted so it closes tight. Casement cranks and hinges have their own page.
Recent JMB work, from our job log
59 installs recorded across 30 Twin Cities communities since Dec 2025. Window and door installs for homeowners and for the builders and dealers we sub for. Counts come straight from our job log; no customer names.
Get a written quote for this job
Three photos and a sentence is enough. You hear back within one business day. Or text the photos to 763-204-2099.
Related jobs we do
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Read morePage reviewed September 26, 2026 · JMB Builders LLC, MN license BC809005 · All windows pages
Where we work
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Based in Zimmerman, scheduling across the Twin Cities metro. Closest first: