Blue tit nest building in August??!

Hi Paul and Ann, very much had my son on my side re boxes.  Had a friend make me a new box (with three holes so it mimics my concrete lucky box) and made hubby feel very guilty about not being able to use it.  Son and I got together and persuaded hubby that it made sense.  Wires all hidden behind down pipes so maybe not in perfect positions but will wait and see.  Cannot watch both at same time but at least got two options or chances now. 
Sue
So intrigued with your box Paul - fascinating.