Loft conversion , new circuits

[jamesmerrix]

hi,
I am part way through a loft conversion and will need to start the wiring for the electrics fairly soon. It will have a bedroom bathroom and landing.
I will be running a new circuit for the lighting, and a new one for the sockets. I just want to get the wiring in before the floors go down, ready for someone to hook it up to the consumer unit.

I am going to go for electric heating as we use it so little the running costs will be insignificant.
I am going to have a panel heater, towel warmer and about 800w of ufh in the bathroom. Will this need it’s own circuit, or can it use the socket ring?
Thanks for your help
James

 

[Simon35]

Presume you are doing this under Building Regs approval?

In which case, get an electrician involved now, so you can get a completion certificate when the time comes. They may be happy for you to do some of the work, but they will want to know what and how you have done it, because they will ultimately take some responsibility for it.

You say you are going to run the cables and somebody else will hook it up to the CU. It doesn't work that way.

 

[ericmark]

There are three ways to deal with Part P requirements, one is use a scheme member electrician, the other is use building control, and in England not Wales scheme members can be authorised to do same as building control and inspect other peoples work. In all options they have to be involved at the start.

Although the only legal required paperwork is either a compliance or completion certificate, in order to issue this some other paper work is also required, the installation certificate can have three signatures, one for design, one for installation, and one for inspection and testing. The LABC does not need to issue an installation certificate, all they need to do is to verify your readings before accepting your installation certificate, or use the electrical installation condition report to show it is safe.

However it is up to you to design, it is not down to a collection of forum members, or the inspectors, it is down to you, the BS7671 gives us guide lines, like up to 2000W limit on a ring final, but you need to work out Kirchhoff's law or be reasonable sure your no where near the limits.

The cable used for a ring final is 2.5 mm² the rating is variable according to how installed, often around 22 amp, however the supply to a ring final is normally 32 amp, so power from centre of ring will be equally shared, but as you move towards the source so the share becomes more and more weighted to one side.

It is likely there is no problem, and all can be supplied from one ring final with FCU's or 13A sockets limiting to draw from each point to 13A, however we don't know, only the designer and installer knows that. i.e. you.

 

[flameport]

I will be running a new circuit for the lighting, and a new one for the sockets.

Why not extend the existing circuits?
A typical bedroom and bathroom is an insignificant additional load.

 

[AndyPRK]

Will you add windows?

someone with disagree, but regarding the heating.
How about running a 4mm or 6mm cable upto a consumer unit. And then having 3x 16A MCB's for the heaters .