The Peterson built nest box has been developed and refined over the last 30 years by Dick Peterson of Minnesota.
The nest box features a large steep roof to provide protection from the summer sun and to make predation by raccoons and cats more difficult. The oval door makes it easier for the adults to feed there young without going into the box. The door opens easy for clean out. I put them on a 5' - 6' steel fence post. $35 per box, painted $45, cash only. Bluebirds are beneficial to your yard as they consume a good amount of insects.