This derivative makes several changes to its ancestor. The most obvious change I removed the perch and added a predator guard instead. I read from many sources that a perch is never needed for the inhabitants and only serves as perch for a predator to eat them instead.

The purpose of the predator guard is to add 1.5 inches between the entrance and the nesting.

I added air vents on the top front and back and 4 small drains at the bottom. These help make for a healthy nest.

I could not find any 3mm plywood at my local Home Depot, so I changed the depth of all the finger joints to accommodate 5mm plywood. Interesting, this is also works for the width of common shipping box cardboard. I made a great cardboard version too.

I also made some of the joints a little larger so that it could be practically cut with a CNC machine as the one in the picture was cut (while I finish work on my new laser cutter). It will cut fine on a laser cutter too.

The birdhouse in the picture has not been glued yet.

Cut the holes first (red lines).

The required tool is either a CNC machine or laser cutter.

Please let me know if you have any questions!