How to Replace a Window Sash

A window sash is the pane of glass and the affixed wooden, vinyl or aluminum framework.

Select a Replacement Kit

A sash fits into a window frame in a sliding track. A window sash replacement kit provides the new sashes and jamb hardware for your window. New jambs and sashes improve your energy efficiency and can fit the architecture of your home. To replace a sash, use the following instructions. .

Measure the existing window sash width from inside one side jamb to the other.

Slide the tape measure between the sashes to measure from inside the head jamb (upper rail) to the inside of the sill. This is the sash height.

Record the jamb depth measurement.

Take these measurements to a hardware store or specialty window retailer to find a replacement kit.

Remove the Existing Window Sash

Twist the lower sash to lift it out of the window.

Pry out any inside stops (between the sash and the jamb) using a pry bar.

Remove the upper sash.

Detach the existing side jambs and jamb hardware with appropriate screwdrivers and pry bar if necessary.

Install the Window Sash Replacement Kit

Screw the new metal jamb brackets into place in the window frame.

Affix the new jamb liners and jamb hardware to the jamb brackets.

Install any specialty or optional hardware included with the kit according to instructions.

Slide the new upper window sash into the outer jamb track.

Lift the new lower sash into the inner track.

Reinstall any inside stops with nails.

Things You Will Need

  • Tape measure
  • Protective glasses and clothing
  • Pry bar
  • Screwdrivers
  • Window sash replacement kit (see Section 1)
  • Hammer
  • Nails


  • Donate your old windows to an architectural salvage store.
  • If desired, prime and paint the new sashes prior to installation.
  • Use wooden sash kits to maintain an historic appearance on an older home.