Without knowing what part of the UK the OP is from it's hard to know whether driving to work is even a sensible option. Companies in big cities often don't have staff parking and public parking is inevitably at a premium.

I'm surprised there are apparently no stairs. Unless there are stairs reserved for emergency use only (which seems unlikely) then working on the 3rd floor without stairs would seem like a fundamental breach of fire safety regulations. How would you evacuate in the event of a fire if all you've got is a very slow lift (especially given standard advice not to use the lift in an emergency)?