WW - any chance you could use a portable air cooler/conditioner, so that you don't have to have a window mount aircon (unless of course you've got an aircon already installed in the wall), and then maybe rather than have to open your blinds you could just pop the air con on for an hour or so before you hit the sack to cool the room? Or fight fire with fire and if there is a room of yours that shines into one of their bedrooms then change to a 100Watt super mega bulb and shine the bejesus out of them!

Re "cascade of intervention", I'm pretty sure that term is used word for word on the 'mybirth' website (.au) and I think that website probably freaked me out a bit but it certainly opened up my eyes to a few things.