Jubbly Boy said:here is a handy link http://www.partp.co.uk/consumer/index.asp
they seem to take an all-embracing view of what the householder can't do on his own (partial quotes)
The list below describes the types of electrical installation work and locations that require advance notification to your local authority's Building Control department.
Type of work
Ring/radial power
Lighting circuit
...extractor fan
Cooker
Location
Flat
Dwelling house
Doen't leave much, does it?
I see it has an 0870 (high-cost) number for enquiries, and I haven't yet found the name and address of the publisher of the website. (edited to say, it says it is hosted by the ECA, The Electrical Contractors' Association
It has the look of an organisation seeking to improve trade for approved companies and seeking to dissuade householders from doing anything themselves.