"Pet @ www.gymratz.co.uk" wrote in message
. uk...
Mike wrote:
Assuming you mean fibre or Rockwool, that doesn't even meet the current
building regs, let alone actually make a real attempt to save energy.
265mm
is needed so regard 300 as a min.

Surely the gains of going from 200 to 300 mm of rockwoolor whatever
would be pretty insignificant compared to heat loss through walls and
windows in a 70's construction house?

True. But if the latest wheeze from the ODPM comes to fruit you will have
to bring the house's insulation up to scratch before you sell it so unless
there isn't a cavity get this filled with insulation as well. And if you
have a hollow underfloor then this will beed to be dealt with as well.