Anyone know if the current guidance that a qualified electrician should do any work extends to eg. changing light fittings, or is that just dealing with the ring main etc?

Andy

http://electrical.theiet.org/building-regulations/part-p/faqs.cfm

Q5: What types of electrical work are ‘non-notifiable’?
The following types of work are non-notifiable:
Replacing accessories such as socket-outlets, control switches and ceiling roses
Replacing the cable for a single circuit only, where damaged, for example, by fire, rodent or impact (1)
Re-fixing or replacing the enclosures of existing installation components (2)
Providing mechanical protection to existing fixed installations (3)
Installing or upgrading main or supplementary equipotential bonding (4)
Work that is not in a kitchen or special location and does not involve a special installation (5) and consists of:
– adding lighting points (light fittings and switches) to an existing circuit (6)
– adding socket-outlets and fused spurs to an existing ring or radial circuit (6)

You can DIY pretty much anything but you will need building regs approval, which will require testing, for certain jobs. There is a reasonable guide here. It is often easier and cheaper to get someone in.

http://www.diynot.com/wiki/electrics:part_p:diy_electrical_work_and_the_law

This will be helpful, too
http://www.planningportal.gov.uk/buildingregulations/approveddocuments/partp/

Pretty sure you can change existing fittings/repair small sections as long as its not in a kitchen/bathroom/outside.

If you are going to mess with light fittings, find the circuit diagrams on DIYnot.com as you’ll likely have 3 or four cables coming into the fitting, and just joining the same colour wires together will bugger up other lights/light switches 🙂