@Wtfdoipick
Contact the planning department at the council first thing tomorrow. If it's raised platform it'll need planning consent. If your neighbour is a complete arsehole rather than just unthinking then it's going to take a while to sort but the planning department don't like people who ignore them.
This. ^ Straight to the council I would go. What an absolute nobhead building something like that, that looks straight into the windows of your home.
And why the fuck should the OP put frosted film on the daughter's window so the men can't see in? Why should she get blinds or a trellis and a climbing plant? Or keep her curtains shut?!
He should NEVER have built this, so it looks into the OP's house!
I would report this to the council, because you can bet this bellend never got planning permission.
How horrible for you @Julshk73
I hope it gets sorted soon. This neighbour sounds fucking dreadful. Is it an option for you to move?
@osbertthesyrianhamster
It's pretty unbelievable, isn't it? Who builds a fucking bar in their back garden in a residential area and uses it as party central?
Inconsiderate, arrogant, entitled nobheads, who think the world revolves around them. The same arseholes who play music super loud, because they think the entire world should hear their shit music, and who leave trash lying around when they have been to the beach or park, and who throw crap out of the car windows into the grass verges, and who let their dogs shit on the footpaths, and piss up people wheelie bins, and who let their dogs off the lead and say 'he won't hurt you, he only wants to say hello' when the mutt leaps on you/jumps up you.
Entitled nobheads. There are quite a few about sadly...
It speaks volumes about the posters who are defending this neighbour ... And yeah, a few people ARE defending him, by saying the OP should just get frosted film for her daughter's window. Or just close the curtains! 
WTAF?!
Are you actually serious?! No way in hell is it OK what the OP's neighbour has done. Needs reporting to the council. Tomorrow. They will make the fucker take his shitty bar down.