These plans can be used to build a bluebird nest box from a single 5' plank of 1" x 6" lumber. The front of this nest box swings open to allow for easy cleaning by removing the two bottom front screws. Leave 1/4" space at the top of front for ventilation. Galvanized or coated nails hold better than smooth nails. To avoid splitting the boards with the nails use a slightly smaller drill bit to start the holes. The top can be beveled slightly to fit snugly against the back. Bluebirds use a 1.5" diameter entrance hole with the bottom of the hole ~6" above the floor. Clean the box out every Fall. Birds will nest in Spring.
A light colored paint or stain will add years to the use of the box. A non-toxic paint such as latex should be used and applied to the outside only.
You can optionally add a peg (dowel) about a half inch below the entry hole to assist with landing and access, but I have been informed by a local ornithologist that this may allow larger birds to land on the peg and harrass the occupants, so my recent builds have removed that feature.
Birds that use a smaller entrance will also use this box. Larger birds, of course, will not be able to enter.
Common occupants in the Western U.S. include:
Place the nest box on posts, snags or tree trunks 4' to 15' above the ground. It gets hot inside the box when exposed to direct sun so select a spot that is shaded from the afternoon sun. A Western exposure tends to work well.
Bluebirds are extremely territorial. The boxes on your Bluebird Trail should be placed no closer than 100 yards. Bluebirds prefer open areas that are adjacent to open fields. House Sparrows will be discouraged if box is set up away from farm buildings. House Wrens will use the box if placed in or near heavy brush.
Approximate Cut Calculations: (a single 5 foot long 1" x 6" pine plank works well.)