Advice on downlighters required please.

Chuffy

Hi, we're currently doing a room in our home and would be grateful for some advice on the lighting aspect.
We're going to replace the ceiling rose with several downlighters.
The room has loft insulation above it.

Questions:
what precautions do we need to take into consideration with regard to the insulation? Do we need smoke hoods or fire-rated lights?
What are the advantages/disadvantages of 12v over 240v?
Is any particular style of light more efficient or cost effective than others?
Are the works notifiable?
Is there anything else we need to be aware of?
Finally, if we get someone in, what sort of price would we be looking at?

Many thanks.

brightontraveller

List ofunder part p works
http://www.southbucks.gov.uk/documents/overview_of_works_covered_by_approved_document_p.pdf
http://www.abletek.co.uk/partp_electrical_work_not_covered.php

Depends on the fitting you buy. Yes fire rated (there are exceptions)
Fitting usually specify a minimum space around the fitting
I would not recommend hoods there cost is higher when you include lights etc also if you choose low voltage the transformer is the outside of hoods hard to replace as hoods normally pinned in four corners low voltage lights the bulbs last longer but transformers need replacing, mains bulbs voltage bulbs last less time but no transformers to replace avoid square types there are hard to line up


If for a single cable in likely to be surrounded by thermal insulation over a length of .5 m the current carrying capabilities insulation the current carrying capabilities in the absence of more precise information as 0.5 the current carrying of a cable clipped direct to surface and open e.g. half its original

You would not be able to cost without more information if existing cable runs along route of lights £150 200 no lifting floor boards no running new circuits drilling joist no replacing parts of ceiling e.g. lath and plaster etc but if you have to do the above it could double the cost

BS regs 532-04 will give you more information on cable