Step 1: Measure Window Width
- Inside opening sash width
- Sash on the bottom sill
- Middle where the sashes meet
- Top sash
It is important to use the smallest of these measurements when ordering windows.
Step 2: Measure Window Height
Measure the inside opening sash height. Then measure from the top to the bottom of each sash. For functionality, top sash is expected to be about an inch shorter than the bottom sash. The combined measurement of both sashes will give you the total height.
Be sure to record the total window height from the left side, center, and right side of the window. Use the smallest of the three total measurements when ordering windows.
Step 3: Measure Window Depth
Measure the windows jamb depth. This is the “pocket” the sill will fit into. This measurement should be between 3.5 inches and 5.5 inches. If the pocket is outside of this range, modification to the pocket may be needed and you should call an expert.
Step 4: Determine the Sill Angle Using an Angle Finder
Measure the windows sill angle. Instead of the tape measure used in the other measurements, you will need an angle finder for this step. Place the finder in the lower corner of the window and measure the angle to the nearest degree.
These measurements will help estimate the size of the window you need, but a window expert will be needed to determine if the window is “out of square” or “uneven” if the house settled and to assess the frame condition. Remember, no reputable window installer will give you a quote over the phone. The installer will want to take a look at your windows in person.
Additional Tips for Ordering Windows
To ensure the window will fit in the opening, you should always take measurements from inside your house and use the smallest measurement when ordering a replacement window. There may be issues inside the frame or wall that Marvin installers are specially trained to identify.
We recommend not removing the window yourself and instead hiring a Marvin Expert to assist with the removal and replacement of your windows. A Marvin Expert will take final measurements for your replacement windows and will order and replace the windows for you.
DIY or Hire a Pro?
Marvin and Integrity from Marvin windows and doors are only installed through approved Marvin installers. Find an installer near you. Other brands sell directly to homeowners or through big box stores (Home Depot, Lowes, etc.) but hiring a window professional is recommended to ensure long-term, leak-free performance. Installation is as important as the type of window you choose.
Once you choose your Marvin/Integrity authorized installer, a window or door replacement project typically takes 6-8 weeks. Your replacement contractor will work with you to schedule an installation date and time that is convenient for you. Installation time varies depending on the number of windows being replaced.
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