troyphoto
Snarky Old Fart (in training)
Build the box on the ceiling, where you want to get access to the window. The box will have three sides, left, right, and back. The front is the window itself (or the wall around it). Build it at least as far back as any swing in the window. It should run the full width of the window, side to side. The depth of the box will be the distance between the joists above, and the level of where your drop ceiling will sit.How big a box Troy 6 inches. 12 inches etc. ?
Swal
Here's a top-down view of what I'm thinking.