Select all the windows and paths....

Grab the Shape Builder Tool

Hold down the Option/Alt key

Drag across what you don't want.

This will have a tendency to make each of the 4 window panes separate shapes rather than one shape with two lines over it.

Select all the windows and paths....

Grab the Shape Builder Tool

Hold down the Option/Alt key

Drag across what you don't want.

This will have a tendency to make each of the 4 window panes separate shapes rather than one shape with two lines over it.

NOTE: You will want to ensure your dividing lines actually touch the edges of the window shapes. You've got a couple lines that don't fully extend to window edges.