Birding Top 500 Counter
Dean Birders
Thinking of putting up a nest box this spring?  Here's a few thoughts ...
 
Holes
25mm - Blue Tit & Coal Tit.
28mm & 30mm - Blue Tit, Coal Tit & Great Tit.

32mm - Blue Tit, Coal Tit, Great Tit, House Sparrow & Nuthatch.
Open Front?
Good for Robins, Wrens & Spotted Flycatcher
Position
Place about 5 - 10 feet off the ground, brass nail or screw to fix to tree trunk facing between NE & SE (out of the worst weather), under cover of branches in a tree or Ivy leaves. Just to shelter from midday sun, winds from the West and heavy rain.
  
If you position a box on an open wall or post it makes it easier for predators & weather to get at the birds nesting in them.
 
Don't open the box during the nesting season.  It may seem abandoned, but you have missed the parents going ain and out and could disturb them causing the chicks or eggs to be abandoned.
 
Clean the box in November after every season and do repairs if necessary. Remove old nest material, pour boiling hot water over insides to kill any bugs that may be present and be careful that you do not scald yourself.