So are you saying the current ground floor ceiling is completely solid?
It's solid but it's got some horrid sort of 70s ceiling tiles glued to
it. They really need to come down!

What about surface-mounted halogen spots, like http://tinyurl.com/75skt (or
http://www.screwfix.com/app/sfd/cat/cat.jsp?cId=101858&ts=81925)?

Thanks. Are you suggesting I mount these on the wall? It will certainly
look better than what's there now, but not really what I'm after. The
ceiling is about 6'9" from the floor, so if I take a couple of inches
for the pipes + the thickness of the plasterboard that brings us to
6'7" - I'd certainly have to duck to walk under those lights. Do you
know of any recessed flourescent fittings ?