On Mon, 20 Aug 2007 05:33:23 -0700, a particular chimpanzee,
randomly hit the keyboard and produced:

my problem is that my architect is telling me otherwise.
I don't have the time+skill to do his job (though I'll probably do the
wiring), and I worry that building control / inspectors might be
equally difficult. Where does it say that extensions to old properties
are exempt?

In the Requirements of Part M (Access to and use of buildings). Go to
the Planning Portal website. Near the front of Approved Document M is
the legal requirement in green. Requirement M1 (Access and use) says,
"the requirements of this part do not apply to an extension of or a
material alteration to a dwelling". M2 and M3 only apply to
extensions to buildings other than dwellings. One caveat; the work
must not make the existing building any less compliant than before the
work was carried out, i.e., you can't replace existing sockets and
switches that comply with ones that don't.
--
Hugo Nebula
"If no-one on the internet wants a piece of this,
just how far from the pack have you strayed?"