Separating One Room

[dudders]

Hi - as you can see I'm new here, but expect to be around a bit in the future, posing awkward questions!  

I've always managed fine in the past, but this one has brought on a serious bout of head-scratching.  An offer to rent from me a downstairs room as an office means I need to separate that room electrically from the rest, installing a meter and CU.  All ways on the main CU are taken and none can be combined.  There are 3 rooms on the power ring that includes the new office, so my plan is to tap into this ring with a junction box, lead off from this to a meter and CU in the new office - with 2 ways, one for power, one for lights.  Then hook the office sockets together to run in a ring from a 32amp MCB and the lights on a 6amp.  No RCD in the CU as there's already one in the main CU.

Simple enough, but I'm uneasy about it.  These questions I'm trying to get my head round:

1. Wouldn't this be classed as a spur?  Can I run a 4-socket ring through a meter on a spur?  

2. If so, there's the question of weight of cable from the junction box to the office CU - whilst everything else is in a ring, this section wouldn't be, so I should perhaps be using 4mm for this bit instead of the 2.5 that serves everywhere else.  

3.  There doesn't seem much point in using a 32amp MCB in the office CU if there's already one serving the main ring.  But the office ring needs to run from somewhere...

4.  A solution to problem 2. might be to run the supply from the main CU directly into the new meter, continue it from there in its previous circuit to the other rooms and have the return line also stop off at the meter on its way back to the main CU.  That way, everything everywhere is on a ring with 2.5mm cable.  But it does mean having 4 cables at the meter's input, which may be a bit much?

Confusion setting in!  Any thoughts would be welcome - thanks for taking the time even to read this.

 

[ProDave]

No no no

Don't start tapping of a ring final to feed a CU to feed another ring final. just not the way to do it.

Fit a completely new, 2 way "garage CU" with one mcb for sockets and once MCB for lights, and of course an RCD

To power the new CU, splt the meter tails with henley blocks AFTER your consumption meter.  Fit your own electricity meter in these tails for billing your tenant for their usage.

As this is in the DIY section, I humbly suggest this may not be work you want to do yourself, and you might be advised to get a local electrician to do it for you.  This is NOT a job for an untrained DIY person with the best will in the world.

 

[ParkySparky]

^ +1

Please don't do anything you have suggested in your OP

 

[SPECIAL LOCATION]

Waste of time and effort...

Just write into your rental agreement a fixed rental that includes amenities or do a proportional percentage of the whole bill divided according to floor space or simiar....

You need to be careful of overcharging your tenant as legally you are NOT allowed to sell electricity for more than you paid for it...

You may need to have to be able to prove that any meter you did install was correctly calibrated the same as the main property suppliers meter...

For the sake of 1 room I would just go down a fixed charge for the room inc heat & light!

http://www.adviceguide.org.uk/nireland/consumer_ni/consumer_energy_supply_ni/consumer_energy_bills_e/consumer_paying_your_energy_bills_e/paying_your_landlord_for_energy.htm

http://www.uregni.gov.uk/uploads/publications/Guidance_for_Resellers_of_Electricity_or_Gas.pdf

http://www.landlordzone.co.uk/FAQ/index.php?action=artikel&cat=1&id=90&artlang=en

etc..

Who does it not apply to?

The maximum resale price rule does not apply to gas or electricity resold for use at industrial and commercial premises, e.g. shops and offices

. However, if, for example, the proprietor of a shop happens to resell some of his electricity to a domestic tenant in a flat above the shop, the maximum resale price will apply in respect of the resale to the domestic tenant.

It does not apply

when an inclusive charge is made for accommodation - for example, where a tenant pays a charge of (say) £100 per week, which includes "all amenities" and identifies no specified charge for the gas or electricity.

Housing benefit claimants on inclusive rent may have notional deductions made from that rent for energy charges, to determine their "eligible rent". Such deductions should take into account the maximum resale prices allowed in accordance with this leaflet.

Maximum resale price also does not apply

to the resale of liquefied petroleum gas (LPG), either in cylinders or through bulk tank systems

You do also need to be careful between domestic and commercial use?

You say this is you house..  but renting part out as an office??

Before thinking about any electrical alterations you need to fully check you legal obligations and options..

If after all that you do still want to go down some sort of metering route then as said this is not DIY work..

The way you are proposing and the questions asked IMHO show that you are not competent to undertake this work and should employ a  qualified electrician who can design install and test the work to ensure it is safe for everyone using the property.

 

[steptoe]

one thing puzzles me,

how would you intend to certify this work in the respect that you are obliged to ensure it complies with HSAW and probably EAWR as it will be for commercial use,

massive difference than for simple domestic use,

it is now for commercial gain,

as said above,

its really not a DIY project, no matter how competent you may think you are, you have legal obligations to your tenant, and the insurance co may be interested as well.

 

[dudders]

Thanks for all the advice - never was happy with that idea, which is why I came for advice.  Now looking at splitting the supply as suggested and taking a line to the room in 6mm cable (about 5 metres, so too far for 3m max tails) where it would go through the meter to the CU - 6 & 32amp mcb's + RCD.  2 light units and 4 sockets already in situ can be hooked up to this.  

Any work I do gets tested and this would be no exception.  Charge to the tenant would be the same rate I pay.  Meter would be new digital.  Office use is already officially allowed.

Did consider just including power in the rent, but believe in the principle of paying for what you use - it concentrates the mind wonderfully on keeping consumption to a minimum.  A guy I know leaves 2 computers running (not just standby) 24 hours a day 7 days a week - he's not paying the bill.

Hope this sounds better...

 

[Doc Hudson]

Thanks for all the advice - never was happy with that idea, which is why I came for advice.  Now looking at splitting the supply as suggested and taking a line to the room in 6mm cable (about 5 metres, so too far for 3m max tails) where it would go through the meter to the CU - 6 & 32amp mcb's + RCD.  2 light units and 4 sockets already in situ can be hooked up to this.  

Any work I do gets tested and this would be no exception.  Charge to the tenant would be the same rate I pay.  Meter would be new digital.  Office use is already officially allowed.

Did consider just including power in the rent, but believe in the principle of paying for what you use - it concentrates the mind wonderfully on keeping consumption to a minimum.  A guy I know leaves 2 computers running (not just standby) 24 hours a day 7 days a week - he's not paying the bill.

Hope this sounds better...

32amp MCB for a single office sounds rather extreme to my mind?

Doc H.

 

[binky]

20A plenty, and can be run as radial cct

 

[ProDave]

Thanks for all the advice - never was happy with that idea, which is why I came for advice.  Now looking at splitting the supply as suggested and taking a line to the room in 6mm cable (about 5 metres, so too far for 3m max tails) where it would go through the meter to the CU - 6 & 32amp mcb's + RCD.  2 light units and 4 sockets already in situ can be hooked up to this.  

Hope this sounds better...

I do hope you are not suggesting splitting the meter tails at the existing CU and taking this 6mm t&e straight from the henley blocks without any circuit protection?

You will need an MCB or fuse and an isolator to protect this cable, so a very minimum of a switch fuse to feed this cable from the henley blocks.  And that's assuming the cable routing method does not dictate the need for rcd protection.