Design Changes For Eastern Blue Bird House

I am not trying to make this a perfect bird world,however just want to share my field experience from my backyard,regarding design changes for blue bird houses.
Ventelation is very important,especially on all four conners of the floor.You can either precut the floor first or drill after assembly. Probably quarter inch or alittle larger hole.Remember the nest material will block a portion of the hole.So if you want it to be larger it is okay.
For the floor I added a piece of l/16th inch plywood over the pine to extend the life of the floor. Believe me it works.