Hmm... my advice would be to make it clear, in advance, in written form, that any person is welcome to attend but also make it clear that toilet and other specialist facilities for the disabled are not available. Put up a written notice to that effect. You will disapoint some people, you can't avoid that. It may be - and I'm being quite serious here - that future events could take place in the home of a disabled person who has the facilities. You may also need to consider your position as regards personal liability (someone cuts themself on one of your glasses, electrocutes themselves on your PA, fires, God forbid, and stuff like that.) If the authorities turn up to shut you down, just deal with it on the spot the best way you can. Nothing ventured nothing gained but it is worth remembering that health & safety regulations are there for very good reasons to protct us all. Good Luck.