My kitchen and living room are tiled in 2' square indian slate which
are about 2" thick and layed on about 1" bed of cement. The whole house
has a concrete screed floor, so there is about a 2" step up into the
room which always catches people out. How difficult would it be to lift
the tiles and lower the concrete floor so that when the tiles are
re-laid there won't be any step? The whole room is 34' by 12' and the
house is only 6 years old, so I assume it was built to the standards at
that time, but I've no idea how thick the screed or the insulation is.

Thanks for your help.