If you can, try and break up the empty nests around the place you want to keep wasp free.
Wasps give off a chemical signal when a colony is coming to it's natural end which is used by queen wasps to avoid reusing a nesting place.
If you spread the remains of nest around they will not come back there.
I had a giant wasp nest in my compost bin and after spreading the comb around the various compost bags around the garden they haven't come back to nest, though the do visit.
For Morrissey fans :
