1: Initial Measurements

For the initial stages, it's important to measure the thicknesses of the material you're using, otherwise you'll run into surprises if you try to follow the plans exactly as written!

First I cut the spacers. These are approx 2" x 2" x 1" thick. Exact measurement will be done later...

Next, measure your central (untreated lumber) 4x4. I got one that was 8' long, and planned to attach it to an existing (treated) fencepost.

VERY IMPORTANT: Most pre-cut 4x4's are actually planed down to 3.5"x3.5"! Only true rough-cut 4x4's are actually 4"x4".

The plans assume that you have an actual 4"x4" board, so it's important to make this measurement.

Next, I measured the combined width of the 2 spacers and the 4x4.

In this case, it was exactly 5.5 inches wide. (The spacers will actually be on two adjacent sides, when they are attached.)

For the last beginning measurement, measure the exact thickness of the plywood that you're going to use.

The plywood I had was 7/16" thick (not quite 1/2".)

Now we're ready to write out the exact dimensions of our finished bat box.

I just wrote out the modified dimensions in pencil on my copy of the plans.