Hi, The file size for download is about 8MB. And any kind of shape can be attached to the doors and windows holes. It could be a catwalk, an air conditional system, pipes, or anything else. However these holes are rectangle, but that's not a real limitation since ArchiTools has an option to fit in the object in the space available. Attached is a quick rendering of circular hole based on a rectangle shape. ArchiTools resized it so it just fit in the wall.