Exterior Window Trim Headers

While windows are typically trimmed with the same profile around the entire window (or top + 2 sides + sill), another popular option is to simply add a piece of trim to the top of a window, otherwise known as a “Window Header“. Window headers are less expensive than trimming an entire window because only 1/4th of the moldings are required, but still make a big difference in the overall appearance of a building.

Window Header

Window headers usually incorporate some sort of keystone into the middle so as to avoid looking overly “plain”. They typically extend slightly past the width of the window, and side-trim if present.

Commercial window header


Any of Decoramould’s Window Trims, Window Sills and Wall Moldings are usable as a window header. Size needs to be determined carefully so that the header is not too large for a window. Generally:

  • Windows under 4′ width shouldn’t use any piece of molding larger than 6″ in height
  • Windows above 4′ width look good with moldings between 6″ and 9″ in height
  • Very large windows can get away with moldings upwards of 12″

Check out the Window Trim and Sill Proportions page for more information.

Using a Decoramould product with a large, flat top to it is generally not recommended for Window Headers, as rain/snow and other precipitation tends to pool on top, causing damage over time.