Step Two Cut a 22.5 degree angle on one side of the roof piece and on one side of the front piece.
Step Three Drill a 1-1/2-inch hole in the center of the front piece about one inch below the edge that was cut on an angle.
Step Four Screw the two sides into opposite sides of the floor piece using two 1-1/2-inch screws. The taller and shorter ends of the side pieces should be aligned in a parallel fashion.
Step Five Screw the front piece onto the two side pieces and floor piece using two 1-1/2-inch screws on each of the three edges. The angled edge of the front piece should be flush with the shorter sides of the two side pieces and the opposite edge should be flush with the floor.
Step Six Screw the back piece in place so one end of it extends about an inch past the floor using three 1-1/2-inch screws.
Step Seven Screw one side of each of the hinges onto the angled end of the top piece with three 3/4-inch screws for each one.
Step Eight Hold the top piece in position against the front face of the back piece and screw the other side of each of the hinges into the back piece using three 3/4-inch screws for each one.
Step Nine Turn the birdhouse upside down and a drill four 1/2-inch drain holes into the floor near each of the corners.
Step Ten Drill three 1/2-inch ventilation holes near the top of each of the side pieces and into the back piece.
Drill a 1/2-inch hole half way through the front piece about one inch below the entrance.
Cut a 1/2-inch dowel to 4 inches in length.
Squeeze a few drops of wood glue into the hole below the entrance and push the dowel into the hole. Hold the dowel in place for at least 30 seconds for the glue to dry.
Paint the birdhouse in the desired color.
Avoid using plastic or metal to construct a birdhouse, as these materials heat up in the sun much more than wood.
Include ventilation holes on all four sides.
Put the entrance hole near the top.
Make sure the roof has a slant to shed the rain.
Include a few drain holes in the bottom just to make sure water can escape in the event that it makes its way inside.
Build in a way to access the inside of the birdhouse to clean it put periodically (i.e. with hinges).
Make sure the roof overhangs the entrance by at least two inches.
Provide a roost just outside of the entrance hole for the birds to land on.
Set up your birdhouse at least six feet off the ground in an area with a bit of vegetation around to provide cover from predators as the birds dart in and out. If you can find a place to position it that is ideal for the birds but also allows you to observe from a distance, all the better.