Hi
I'm a beekeeper and often get called out to deal with a 'swarm of bees', which often turns out to be a wasp nest.
A few facts about wasps:
They don't survive the onset of cold weather in the late Autumn. Only the queen wasp survives and she hibernates, often in a fold at the back of curtains.
The nest is not re-used the following year.
The nest is made of papier mache, which the wasps collect from fence-posts, garden seats, etc. It normally has alternating layers of white and brownish paper.
So, once winter arrives,wasps' nests can be removed safely. But make sure it is a wasps' nest, not a bees' nest (several parallel slabs of honeycomb) because bees are active in their nests throughout the year - and there are thousands of them!
I normally advise people to leave wasps alone if possible because they will die out in the winter anyway and don't return to the same nest. However, if they are a nuisance, get the council or a commercial pest control company (eg Rentokil) to dispose of them. Or if you know a friendly beekeeper, he might help, or at least lend you a bee-suit.
Regards
Dave