Snap-in insert component for sash windows

A snap-in insert component for non-permanently closing an access opening fabricated near the top of the jamb of a sash window. Locating the access opening near the top of the window jamb avoids air infiltration problems in the window that result when the opening is located below the upper end of the lower sash of the window. The insert component, when inserted in the access opening, provides a bearing surface for a tilt latch on the lower sash when the sash is raised to the point of the access opening. This allows the sash to be raised all the way to the top of the window frame without experiencing un-desired movement in the in and out direction. The insert component can be readily re-moved and re-inserted in the field as the need arises. Because the insert component essentially completely fills the access opening, the appearance of the window is improved.