how to measure existing windows for replacement

Window Frame Dimensions and Measurements for Replacement

Essential Measurements for Accurate Replacement

Accurate measurements are crucial for successful window replacement. Failing to obtain precise dimensions can result in ill-fitting windows, compromising energy efficiency, security, and aesthetics. The process involves measuring several key aspects of the existing window frame and opening.

Exterior Frame Dimensions

  • Width: Measure the exterior width at the top, middle, and bottom of the frame. Record the narrowest measurement.
  • Height: Measure the exterior height at the left, center, and right sides of the frame. Record the narrowest measurement.
  • Depth (Frame thickness): Measure the depth of the existing frame.

Interior Frame Dimensions

  • Width: Measure the interior width of the existing frame at the top, middle, and bottom. Record the narrowest measurement.
  • Height: Measure the interior height of the existing frame at the left, center, and right sides. Record the narrowest measurement.

Window Opening Dimensions

  • Width: Measure the width of the rough opening at the top, middle, and bottom. Record the narrowest measurement.
  • Height: Measure the height of the rough opening at the left, center, and right sides. Record the narrowest measurement.

Additional Considerations

  • Jamb Depth: Measure the depth of the window jamb (the side framing member of the rough opening).
  • Window Type: Note the type of window (e.g., double-hung, casement, sliding) as this impacts measurement and installation techniques.
  • Window Operation: Observe how the window operates (e.g., inward or outward opening) and take appropriate measurements.
  • Sill Depth and Profile: Measure the depth and profile (shape) of the window sill.
  • Head Depth: Measure the depth of the window head (the top horizontal member of the frame).
  • Checking for Squareness: Verify that the window opening is square using a level and measuring diagonally across the opening. Significant deviations from squareness should be noted.

Recording Measurements

Record all measurements in a clear, organized manner. Include units (inches or millimeters) and clearly label each measurement. Multiple measurements of the same dimension are recommended to ensure accuracy.

Recommended Tools

For accurate measurements, use a measuring tape, level, and a square.