How to Measure for a Window Replacement

Measuring for replacement windows is a relatively easy process, once you know the steps. I had to replace over 30 windows on a single project, I've been an expert at this ever since. There are many advantages to replacement windows beyond aesthetics. The savings in heating and cooling costs, due to the installation of modern dual pane glass, will pay you back for this expense project over time.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Tape Measure
• Floor Plan
• Pencil
• Spreadsheet

1. 
    

   Measure from inside the house. Hold your tape against the inside face of the openings. The interior window stops are likely made out of wood casing but it may be sheetrock. Either way, hold your tape measure flush against the stops. Measure in two different locations for both the width and the height. Take the smallest measurement in each case. Err on the side of caution with you dimensions.
   
   Don't forget those hidden windows in closets or store rooms that you may want to replace as well to maintain a uniform look on the exterior.

2. As you make your measurements, write them directly onto a floor plan. If you have blueprints, great, if not, just make a sketch and show the windows as skinny rectangles in the lines representing exterior walls. Draw an arrow to the window with a corresponding bubble attached to the arrow, which is where you write your dimensions.

3. Now, make a spreadsheet on your computer. Create a code number for each window and the window replacement manufacturer will match it on both their proposal and their window shipment. Trust me, this will make the whole project run more efficiently and accurately.
   
   Explain to the window manufacturer that you measured from inside stop to inside stop for both the height and width. Don't provide those dimensions and call them your rough opening size, because they are not. The manufacturer will determine the rough opening based on your interior measurement information and fabricate the window. Also, it's a good idea to email the window sales rep a digital photo of your existing windows, both inside and out.

4. When the windows show up, they will have a sticker on them corresponding to the window code you made up. Just reference your floor plan that shows the code and carry the windows to their replacement location. You don't want to have to measure the windows when they arrive and then start to figure out which opening they go to.