On Sat, 21 Aug 2004 07:42:40 GMT, a particular chimpanzee named
Sapient Fridge randomly hit the
keyboard and produced:

It's that second bit that is causing the problem, if I have less than
half glass then it no longer counts as a conservatory.

Conservatories are exempt from the Building Regulations if they meet
the criteria in Schedule 2 of the 'Regs, which is: "the extension of a
building by the addition at ground level of... a conservatory...where
the floor area of that extension does not exceed 30m², provided that
in the case of a conservatory or porch which is wholly or partly
glazed, the glazing satisfies the requirements of Part N of Schedule
1".

The problem comes in that there is no adequate definition of a
conservatory. IIRC, the old 'Manual to the Building Regulations' gave
it as having a transparent or translucent roof, with no mention of the
glazing to the walls. The guidance in AD L1 only relates to
conservatories to which the Regulations apply; namely those which are
constructed at he same time as the house, or those which don't meet
the other exemption criteria. It's circular logic to apply this as a
criteria as to whether the conservatory is exempt. Unfortunately,
this logic has been adopted by many authorities and/or officers.

There's two separate routes to compliance here;
1. Your proposed extension is an exempt conservatory, in which case,
it doesn't matter how you construct it; or
2. It's an unheated extension, in which case a Building Regulations
application is required, and matters such as its structure, fire
safety, drainage, etc will need to satisfy the Requirements.
With your extension also containing a utility room, I would suggest
that it falls into the second route.
--
Hugo Nebula
'What you have to ask yourself is, "if no-one on the internet wants
a piece of this, just how far from the pack have you strayed?"'