So I've never done anything like this before, and I played it by ear. I researched birdhouse motels online to get some ideas and basic measurements and then opened up my giant Ziploc bag of scrapwood. I found two nice size rectangle pieces and cut the side pieces to fit. For the roof, I cut strips of wood to fit and laid them across. Here's a pic to show the unfinished, unshingled product:
I made the holes first with a thumbtack and then widened them with my pointy clay tool (can't remember what it's called!).
Once that glue dried, I painted the entire thing with Tim Holtz "Picket Fence" Crackle Paint (which I love!!!) to give it that weathered, outdoor look.
I shingled it with some leftover asphalt shingles that I had used on the smaller roof on the herb shop (they match!). I also glued on the pole (which is still a little wobbly and really needs to dry overnight). As you can see in the pic below, I still have some paint touchups to do (on the pole and the holes). In addition, I want to build a base with clay (over which I will glue coffee grounds for soil) that I can attach with Tacky Wax to the base of my scene.