Can you have a "permanent" tent of 2.5 meters high which covers the whole garden?

Question:I live in a terraced house near London. My neighbour has put up a home made roof made of loose plastic and plastic pipes which covers the whole garden. underneath he has a home made snooker table which looks horrible. It will put off any prospective buyers if not removed. Legally, can he do this?

Answers:
gm

Legally?
Check the covenants of your property owners' agreement.

I'd say the guy is inovative. Cheers to him for being a thinker and doer.