Important: These are preliminary quote measurements—not final manufacturing dimensions. Custom windows are made to order. Have every opening and installation condition verified before ordering.
What you will need
- A reliable tape measure
- Paper, phone or spreadsheet for recording each opening
- A pencil and simple sketch of the home
- A level, if available
Measure from inside the home
- Label every opening. Use room names and numbers such as “Living Room 1” so the measurements do not get mixed up.
- Measure the width in three places. Measure near the top, middle and bottom between the side jambs—not from the decorative casing. Record all three measurements and circle the smallest.
- Measure the height in three places. Measure at the left, center and right from the head jamb down to the point where the replacement window will sit. Record all three and circle the smallest.
- Check the depth. Note the available jamb depth and anything that may interfere, including trim, stops, pulleys, storm-window tracks or unusually thick finishes.
- Check for squareness. Measure diagonally from corner to corner in both directions. A noticeable difference may indicate an out-of-square opening that requires additional planning.
- Take photographs. Photograph the entire window from inside and outside, plus close-ups of the sill, trim and any damage.
What not to do
- Do not measure only the glass.
- Do not assume matching-looking windows are identical in size.
- Do not round aggressively or subtract an installation allowance yourself.
- Do not order solely from preliminary homeowner measurements.
- Do not remove trim or disturb painted surfaces unless you understand the risks, particularly in older homes.
What to send with a quote request
Send a list of each window opening labeled by room and number (for example, “Living Room 1”). For each opening, include the smallest of the three width measurements and the smallest of the three height measurements. Also include the window style you want, photographs, the project town and whether installation services are needed.