We have old jalousie windows in the basement above the soil line. The window in the bathroom opens up to the bottom of an added on breakfast room, making the view not so great.

In addition, the window placement makes it impossible to center the mirror on the vanity.

I want to close off the window and then drywall over it since we're about to repaint the bathroom. What's the best way (and least expensive) to seal up the in window in insulate the space?

Thanks,

Bert