Always use corrosion resistant screws and hardware. Drill countersunk pilot holes in primary work pieces (first piece the screw is inserted into). Drill regular pilot holes in secondary work pieces.
You may prefer Side Opening Doors instead of hinged roof doors, especially for the larger nest boxes.
Hinges are suggested for easy access. Other methods for attaching roofs are just as good. However, most nest boxes are mounted out of reach for most people.
Birdhouse mounting, monitoring and maintenance on ladders are awkward chores that require “three hands”. Convenience increases safety when working at heights.
Clean and disinfect nest boxes with a 5% bleach and 95% water mix after the brooding season to prevent spread of disease and parasites. Use rubber gloves, eye protection, spray bottles, and sponges to completely saturate nest box interiors.