Garden office wiring

[jonnypron]

some advice needed. Before I ask advice I will be getting any wiring signed off and completed by a qualified electrician before connecting to the house mains.

I just want to save some time / money by running the cables around the stud frame of my garden office and want some basic advice if anyone can help.

I've done a simple diagram and overlaid what I've been advised is the setup for simple low-power garden office. I just need to know if I need to ring the lighting wiring like the ring main on the sockets to the RCD as well. Also do sockets need to be a certain height off the ground?

I am not entirely sure of the consumer unit required. Is this a simple 2 way i.e. one for lighting and one for mains ring?

Nothing will be high powered... maybe max just a 1kw heater needed in winter. Any advice on how this should be setup, what I've missed etc. I was presuming 2.5mm twin and earth ring for the mains and 1.5mm for the lights?

 

[EFLImpudence]

No, you don't need to 'ring' the lighting.
You don't need to 'ring' the sockets either.

If you want an electrician to 'sign it off' then you really need to employ one now and follow HIS advice.
Outside power is not a DIY job.

 

[jonnypron]

No, you don't need to 'ring' the lighting.
You don't need to 'ring' the sockets either.

If you want an electrician to 'sign it off' then you really need to employ one now and follow HIS advice.
Outside power is not a DIY job.

Never suggested it was a DIY job, but getting electrician to route all the cabling, drilling holes in studs etc will take the most amount of their time and is not a necessity in my book. Everything will be left exposed to check and nothing wired in. I was hoping an electrical might just be able to approve the couple of queries I have.

 

[SFK]

Jonny,
My understanding is - to get Electrician signoff you need Electrician to fit the cable (or you fit the cable under his direct supervision) - not you doing it yourself and then asking him to signoff.

Regarding your drawing, my suggestions would be:
- If fuse box is needed have it higher up the wall.
- Have more sockets.
- Have the two light fittings have two switches (you can always change to one later, but harder to change to two).
- In the side room, Have a socket near the fuse box and another socket and a light and switch.
- Have an outside light on PIR above door.
- Have an outside socket.
- Have a circuit for heating (how are you doing this, Oil filled radiators, electric wall radiators, underfloor hearing, Combined AC/Heating Unit?)
- If two rooms have Smoke alarm in each so you know if one is on fire when in the other.


Height of sockets and Lights are here:
http://www.practicaldiy.com/electrics/socket-position/socket-height.php

Also, just for my info, why do you have a side room, or am I reading the drawing wrong?
SFK

 

[aptsys]

Jonny,

Regarding your drawing, my suggestions would be:
- If fuse box is needed have it higher up the wall.

What about compliance with Part M?

 

[SFK]

Aptsys,
Sorry I do not what the specs are for Part M - I have always tasked the Electrician to meet the required specs and so I would expect expect the Electrician to asses the drawings provided by Jonny, and then install so that it then meets all the required specs.

My comments we intended only to address where I feel the appliances/sockets/switches/etc would be better located, not the specs to do this. I felt his drawing showed the Fuse Box as being too low (at knee height) to easily access and the drawing would be better if the fuse box was at (say) face level.

SFK

 

[Taylortwocities]

What about compliance with Part M?

I rather think that thre is no, zero, zilch requirement for disabled access for this building!.
By assuming so, you would need to question the entire building: width of doors, ramps, disable toilet failities with alarm pull cords, etc.

Get real. The sockets and switches can be at whatever height he wants.

However. And as highlighted above. All of the DESIGN needs to be done by someone who knows what is required, and that will be the electrician who will be asked to certify that he designed, installed and tested everything.

@jonnypron I know you want to save a few pounds. I suggest you engage an electrician and do the wiring grunt work for him. But you need to ask him what, where, etc BEFORE you try and find someone to come and cert your stuff. I can tell you that you will have a long fruitless search looking for someone who will take it on.
Most electricians have plenty to do without having to sign their reputation away on someone who justs phoned up and says "I've just done this......can you just pop in and sign it off."
Imagine you install a gas boiler yourself and then ask a GasSafe (CORGI) man to come and OK it. It's not going to happen.

My other question is about the supply to the building itself. How does that get there? How is it provided? What sort of cable.....?

 

[jonnypron]

Jonny,
My understanding is - to get Electrician signoff you need Electrician to fit the cable (or you fit the cable under his direct supervision) - not you doing it yourself and then asking him to signoff.

Regarding your drawing, my suggestions would be:
- If fuse box is needed have it higher up the wall.
- Have more sockets.
- Have the two light fittings have two switches (you can always change to one later, but harder to change to two).
- In the side room, Have a socket near the fuse box and another socket and a light and switch.
- Have an outside light on PIR above door.
- Have an outside socket.
- Have a circuit for heating (how are you doing this, Oil filled radiators, electric wall radiators, underfloor hearing, Combined AC/Heating Unit?)
- If two rooms have Smoke alarm in each so you know if one is on fire when in the other.


Height of sockets and Lights are here:
http://www.practicaldiy.com/electrics/socket-position/socket-height.php

Also, just for my info, why do you have a side room, or am I reading the drawing wrong?
SFK

Thanks for the info... some helpful pointers I missed out on. The side room is just garden storage e.g. lawn mower, bike etc. The RCU is low because the SWA cable isn't quite long enough to go up to head height. Obviously electrician could extend this with a junction box inside the wall.

 

[jonnypron]

I rather think that thre is no, zero, zilch requirement for disabled access for this building!.
By assuming so, you would need to question the entire building: width of doors, ramps, disable toilet failities with alarm pull cords, etc.

Get real. The sockets and switches can be at whatever height he wants.

However. And as highlighted above. All of the DESIGN needs to be done by someone who knows what is required, and that will be the electrician who will be asked to certify that he designed, installed and tested everything.

@jonnypron I know you want to save a few pounds. I suggest you engage an electrician and do the wiring grunt work for him. But you need to ask him what, where, etc BEFORE you try and find someone to come and cert your stuff. I can tell you that you will have a long fruitless search looking for someone who will take it on.
Most electricians have plenty to do without having to sign their reputation away on someone who justs phoned up and says "I've just done this......can you just pop in and sign it off."
Imagine you install a gas boiler yourself and then ask a GasSafe (CORGI) man to come and OK it. It's not going to happen.

My other question is about the supply to the building itself. How does that get there? How is it provided? What sort of cable.....?

Whatever compliance to Part M is I doubt I have it. you don't actual need building regs for outbuilding under 15sq meters anyhow as far as I understand it. Sure you do need electrician to provide external power to the garden. The power will be provided by an armoured SWA cable from the house. The cable is basically waiting for electrician to wire in to the house consumer unit. It's just sitting there for now into junction box in preparation (surface mounted and buried). I understand the ideal is to get electrician to do the whole job, just was hoping to get away with a day rather than possibly 2 for something that is basically nailing some clips to a wall (if I got the plan completely correct).

I think the best thing is to take advice first from spark on site and see what they say. I wouldn't compare fitting a gas boiler and getting Corgi man to sign it off to what I'm suggesting I want to do which is nailing some cable along the stud wall in the places where I want sockets to be fair!

Thanks for the advice. BTW the door widths are actually full official width for disabled doors funnily enough though not for Part M or whatever that is???

 

[jonnypron]

What about compliance with Part M?

Exempt under Class 6 detached outbuildings as under 15 square metres floor area.

 

[Taylortwocities]

Part M is a Building Regulation, that goes along with lots of other parts.
For instance: Building regulation Part P relates to electrical work.
As well as this, electricians also need to comply with all applicable Building Regulations like B (Fire), L (Energy Efficiency), M (as above), C (Passage of Moisture) , E (Passage of Sound), F (Ventilation) etc

So it's not always as straight forward as you might think.

PS, How big is the SWA? How did youi calculate that would be big enough?
I hope that your underground SWA is buried properly?

 

[jonnypron]

Part M is a Building Regulation, that goes along with lots of other parts.
For instance: Building regulation Part P relates to electrical work.
As well as this, electricians also need to comply with all applicable Building Regulations like B (Fire), L (Energy Efficiency), M (as above), C (Passage of Moisture) , E (Passage of Sound), F (Ventilation) etc

So it's not always as straight forward as you might think.

PS, How big is the SWA? How did youi calculate that would be big enough?
I hope that your underground SWA is buried properly?

Blimey... it's a garden room for occasional use and is under 15 sq metres, so is exempt from most of the building regs you mention above.

Please see link below if you're not up to speed. This was a simple question about some time saving for wiring. The SWA cable is 32A 4mm copper wire... more than adequate for some low-voltage uses and installed by landscape company who did some work on the garden last year (and had assurances it was adequate before being laid).

I was always going to get an electrician to do the work that is required to be approved by licensed electrician, just wondered if routing the cables myself would fall inside or outside the allowed work I could do.

https://www.planningportal.co.uk/info/200187/your_responsibilities/38/building_regulations/2

 

[EFLImpudence]

You're not exempt from Part P,

nor its associated Regulations

http://www.legislation.gov.uk/uksi/2012/3119/regulation/6/made



Talking to electricians in person on site is not as bad as you seem to think.

 

[JohnW2]

Talking to electricians in person on site is not as bad as you seem to think.

I'm sure that it is usually the case, but it does depend upon the electrician!

Kind Regards, John

 

[jonnypron]

You're not exempt from Part P,

View attachment 121403

nor its associated Regulations

http://www.legislation.gov.uk/uksi/2012/3119/regulation/6/made


Talking to electricians in person on site is not as bad as you seem to think.

Thanks for confirming. I was aware electrical additions needed approval i.e. Part P, hence the need to find out about what can and can't be done by myself. As I said it was exempt from MOST parts, not ALL! Appreciate the confirmation though and do not have any issue with any trades and am unsure how you came to this conclusion... hope no electricians have been offended by above posts!