stewart killick
The main problem with fitting a bathroom into a room with no plumbing is drainage, particularly the toilet soil pipe. If one of the walls of the new bathroom happens to be on the same wall your existing waste pipe runs down this shouldn't be a problem, if on the other hand it happens to be on the other side of the house you may need extensive ground works to plumb the toilet in to the main drain. However you can get round this with the use of a macerated ( saniflow)which although many people aren't keen on they do provide an easy solution to this problem by doing away with the 4" pipe and pumping the waste through a must smaller pipe using a pump rather than gravity.