Best Way to Measure for New Storm Windows or Doors
Learn how to easily measure storm windows and storm doors.
By Bryan Dube on January 13, 2018
The time has finally come. You can't ignore the drafts, the whistling, or the rattling in your home anymore. Installing new storm windows or doors are the easiest way to decrease air leakage from your home, without a full replacement installation project.
Once you have determined that you do need to install new storm windows or doors on your home, the next step is to measure the existing frames for their respective storms.
One tip: measure every single window or door individually to ensure a tight fit. Read on for the complete guide to measure for storm windows and storm doors below.
Storm windows come in a few basic versions:
- Single fixed pane affixes easily over the entire existing window. Ideal for installation over basement (non-egress) or rarely opened windows
- Triple track storms include a screen pane in a separate track. This option is great for year-round installation that still accommodates air flow in the summer. Triple track storm windows are great for installation with double hung or slider windows.
Use the guide below to find measurements for any of these storm window types. If you aren’t sure about which kind of storm window is best for your home, contact Acme Glass for a storm window or doors consultation.
How to Measure for Storm Windows
Replacing storm windows sounds simple. But there are two points in the process that can trip up any homeowner or contractor, so it’s often best to trust the professionals to help out with this project. These challenges are: taking the correct measurement to find a window's opening dimensions, and knowing what kind of storm installation is appropriate for your windows.
Initially, you need to determine if you want interior or exterior storms. Interior storm windows are installed inside existing windows, and are perfect for older historic homes, as they won’t change the exterior appearance. These storms can easily be removed in warmer months to allow for air flow, or for cleaning.
Exterior storm windows cause minimal disturbance during the fast installation process. They also serve to protect older wood windows from the elements, which can help prolong the life of existing windows. Proper installation is necessary to avoid moisture caught between the window and storm, so trust the experts for this one.
Next, determine what kind of sills your existing windows have. If you have a standard sill, you will need to take all height measurements from the highest point of the sill to the head. For drop sill measurement, be sure to measure to the bottom of the drop.
(Sill is the bottom frame piece of a window; the Head is the top frame piece of a window; the Jamb is a side of the window)
Next, you need a measuring tape, pencil and paper.
Q: What do I measure if I have existing storm windows in place?
A: Measure the exact dimensions, or “tip to tip” for each existing storm window.
Trip-Up #1: How to measure for a storm window without an existing storm window
- Measure the window width. Start at the bottom of the window above the sill. Measure from the window just inside the frame, across the pane to the other side. In window terms, you’re measuring from jamb to jamb. Measure across in the middle of the window, and at the top as well. Use the least dimension for your window dimensions.
- Measure the window height. Starting on the left side of the window, measure just within the frame, along the jamb or side. Take the same measurement of the window’s height in the middle, and again on the right side, along the jamb. Use the least dimension for your window dimensions.
Q: Why do I have to measure windows three times?
A: It’s common for older windows to have different measurements between these three areas of the window, so note each one. You will always reference the least measurement to find a storm window that fits.
Trip-Up #2: Know what kind of installation your windows require
Eastern Overlap Method - Casing Installation
Eastern overlap installation affixes the window to the exterior trim. This installation is used if the existing window does not have blindstops. The window manufacturer will add to your opening dimensions to assure the proper fit and operation of the storm windows.
Note: Installing an eastern overlap storm window over a window with blindstops will restrict the removal of the screen and possibly the storm sash from the inside of the structure.
Western Method - Blindstop Installation
The blindstop is the portion of the window that holds the upper sash in place; it's affixed to the jambs on the exterior of the window. Mounting storms on the blindstop gives a more recessed appearance which is preferred by most homeowners. The window manufacturer will deduct from your opening dimensions to assure proper fit and operation.
No matter whether you are installing storms with the Eastern or Western methods, you will report the same measurements to your window supplier. Let them know which method applies, if you are certain.
Q: How do I know which installation method is the right one?
A: The only fool-proof method to measuring, ordering and properly installing storm windows is to trust the professionals. If you aren’t sure where to locate the blindstop on your windows, call Acme Glass for a free estimate. Otherwise, you might end up ordering storm windows in the wrong size that don’t fit!
How to Measure for a Storm Door
Storm doors are usually simple to measure, with one method for finding the opening dimensions of the door you have. Make sure that you have at least 1 inch wide by 1 inch deep for mounting and installation for a new storm door.
- Measure the width of the storm door opening. This will be on the exterior of the entry door, as the storm will be mounted to the exterior brick mold trim. Measure across the top, in the middle, and at the bottom of the opening. This will help record an accurate measurement. Take the narrowest of the three measurements.
- Take the opening height, and measure from the threshold, where the storm door will sit, to the door head.
- Assess your handle placement. Make sure there is enough clearance for your entryway door handle when the storm door is installed. If you have narrow door distance and you are in danger of having handles collide after installation, consider a storm door with a flat handle style. Or, hinge the storm door on the opposite side from the main entry door.
For help with measurements or finding the right storm door style for your home, contact the experts at Acme Glass.
If You Don't Want Storms
If storm windows aren’t the look and feel you want for home, there are other options. Perhaps it is time to replace your windows instead for long-lasting energy efficiency, which will save you money in the long run. Download our Homeowner’s Guide to Replacement Windows