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, some birder's use a stove pipe baffle 8" x 24" for predadation control, also house's should face east or southeast to protect from storm's and wind. 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. You can can get a T-post attachment (pitctured)from Tractor supply and if you are close to Rapids I will install the whole setup for you, $35 per box some people like them plain so they can put linseed oil on for a natural look, painted $45, cash only. Bluebirds are beneficial to your yard as they consume a good amount of insects. Bluebirds have a second hatch and the 1st hatch is out and about the end of June and they will switch house's.