I can only add if you are building it, build it once and be done, don't skimp on the money or time b/c it isn't that much more for either to do it right the first time. Go a little bigger than you think you will need, get the window ledge at the right height for the chair you will be using, drop a piece of pvc tubing down one corner and into the ground below with a funnel head so you can leave a leak when u need to. Build a good set of stairs up to the door. And always check beforehand during the early season for bees nest.
