window replacement begins

Window replacement in a building or structure begins at the moment when the first old window is removed as part of a continuous process to replace the majority of existing windows with newer ones. This process is completed when window replacement ends.

The first removed window marks the beginning of a continuous project intended to replace a majority of existing windows. Ordering replacements does not itself remove a window.

Window replacement ends records installation of the last new window in that project. Isolated replacement of a small number of windows is outside the stated majority-based scope.