How to Measure Windows

The first thing you need to know is to determine what type of existing windows you are replacing.

Measuring Wood Windows*

First you should remove the screen and open the window.
Measure the window width from jamb to jamb.
Measure three times, at the bottom, middle, and top of the window in case the old jamb is not square. If there are discrepancies between the three measurements, use the shortest measurement. This is your rough opening size width. If you are measuring exact size it is this number minus 1/4".

Window height is measured from the bottom lip of the head to highest point on the sloped sill Again measure three times, at the middle, left and right sides of the window in case the old jamb is not square. If there are discrepancies between the three measurements, use the shortest measurement. This is your rough opening size width. If you are measuring exact size it is this number minus 1/2".

Measuring Metal Windows*

Start by removing the screen and opening the window. This allows you to determine which flange sticks out the furthest. Measure that flange to the same flange on the other side of the window. This will give you the size of the clear opening you will have once you remove all the panels. Measure the widths at the top, middle, and bottom and use the narrowest measurement. Measure the height in the same way in the middle, left and right sides and use the shortest measurement. This will determine your rough opening window size. To measure the exact window size deduct 1/4" from the width and 1/2" from the height of your measurements.

Installing Your New Windows*

This project requires only basic tools and skills. It's not unusual for window replacement companies to charge $500 or more per window. That's about $200 for the vinyl window and $300 for labor and overhead. Before deciding to tackle the job yourself, check the condition of your existing window frames. If they're rotten or badly out of square, the whole unit, including the frame, may need replacing. This is a much bigger and more complicated job than installing a vinyl window insert and may require a pro.

If the frames are sound, the next step is to measure the interior width and height of each window frame side to side and top to sill. Double-check these measurements to ensure their accuracy so you don't end up with a window that doesn't fit.

Use these measurements to order the windows from OrderWindowsOnline.com. The price will vary depending on your size and the features you request.

The windows install from the inside. Give yourself at least half a day to install the first unit. Once you've learned the steps, the second installation will go much faster.

Here's a summary of the steps:

1. Remove and save the inside stop. It'll be reused in the same place.
2. Remove the old lower window sash (not shown).
3. Pull out the parting stop (see top frame detail). Don't worry about breaking it; you won't be reusing it.
4. Remove the old top sash (not shown).
5. Either remove the sash liners and springs or open the sash pockets and pull out the weights. Remove the sash cord pulleys and stuff the weight pockets with fiberglass insulation.
6. Push the new vinyl unit into place tight against the outside stop and drive the mounting screws in the sides.
7. Caulk around the outside and install the vinyl trim pieces.
8. Reinstall the old inside stop.