Design for complete house rewire

Discussion in 'Electricians' Talk' started by DedicatedDIYer, Jan 22, 2021.

  1. DedicatedDIYer

    DedicatedDIYer New Member

    Hi all,

    I came up with this wiring design for a complete rewire for my home. Can I get some electricians to review this design? One area I need help with is what cables to leave for the secondary consumer unit which will eventually be installed for the outbuilding. The outbuilding will be used as a workshop.


  2. FlyByNight

    FlyByNight Active Member

    I guess this is the spec you will be giving to your electrician to quote against?

    As it will be a major task, have you also consider getting network cables installed at teh same time? Also, do you have a location where your Broadband modem/hub/router/switch will be? And exrtra sockets for those?

    What about a dedicated spur for an intruder alarm?

    What about outdoor (IP65) rated sockets - one at front and one at back of house?
  3. Hans_25

    Hans_25 Screwfix Select

    Its good to spell all this out - Sparks and other trades generally welcome a clear definition of what they are quoting for.

    Rather than cluster the above per "circuit", you might want to structure it on a per room basis and then show for each room the number/type of sockets/lights/other required (other would include cooker). Each spark will have their own idea of the best circuit design taking into consideration loads, distance and number of connections.

    E.g. I had specd out downstairs and upstairs rings, but the spark suggested a better idea of doing right house and left house as the Kitchen was on the left side with only one bedroom above, lounge and 2 beds other side. For lighting I have 3 circuits, I think they are downstairs, upstairs and a third one for the hall & landing lights and smoke sensors.

    Agree with above its good to think about network cable (Cat6 here), its easy enough to install at the time, do you have a central place where network cables can come together via a patch panel? Easy then to connect things up. And if you have network cable, easy to add one or two commercial grade Wireless Access Points (Ubiquiti AC PRO) that attach to the ceiling. I have one in the kitchen, covers the whole house.
  4. DedicatedDIYer

    DedicatedDIYer New Member

    Yep for a quote too but that it'll include additional details for installation.

    Yes I have a home network plan and router/switch/access points have already been accounted for.

    CCTV encompasses the alarm.

    Any outdoor sockets will be of suitable types, they are already included in the plan, Front/Rear.

    I may also add a circuit for the garden lights.


  5. Hans_25

    Hans_25 Screwfix Select

    Double shielded CAT6 or 7 cables will be v difficult to route, standard Cat 6 is way more than enough and a LOT easier to work with. A 35mm backbox is only just deep enough for standard Cat 6.
  6. DedicatedDIYer

    DedicatedDIYer New Member

    Is it due to its rigidity? The reason I would like this is to minimise interference from mains cables, not due to increased data speeds, although this may be a good idea for future-proofing. I don't understand why the 35mm back box will be a problem for Cat 6 cables? If it is, I can go for deeper back boxes.
  7. FlyByNight

    FlyByNight Active Member

    Outdoor socket - put them on their OWN RCBO and not shared with the ring.

    Have a DEDICATED fridge/freezer socket - that way if you are away and something trips te ring, the freezer stays powered.

    Also worth asking if the electrician can split the tails in a suitable "Henley block" and have your main CU, then in a second small CU, the MCB/RCBO/RCD for your EV point, and outbuilding/workshop.
  8. FlyByNight

    FlyByNight Active Member

    Cat6 can be a pain to run ... especially in restricted domestic locations. 10 years back I installed 600m of Cat5e in my own home and that is still fine for a full 1 Gbps. It runs close to and crosses power cables and I d not suffer noise issues. Cat6 maybe - but not double shielded or Cat7.
    Hans_25 likes this.
  9. DedicatedDIYer

    DedicatedDIYer New Member

    Thanks, I'll place the fridge freezer on a separate circuit.

    Would the second small CU for the EV and Outbuilding be suitable as the EV charging point is at the front of the house, and the outbuilding is at the back of the garden? I read the cables should not travel too far from a CU, hence my plan was to have the small CU at the outbuilding from the main CU. Didn't think about splitting the tail yet.
  10. FlyByNight

    FlyByNight Active Member

    The second small CU is just there to have the control switches for the two circuits. For example. The device in the small unit trips at say 40A with suitable SWA going to the outbuilding, and then it gets split to the individual circuit. It allows you to protect the cable and also, if you wish, turn it off.

    Again , talk to your electrician. Just that with the amount of circuits, you will be tight on space. So pulling the two "remote" circuits in a separate unit - all teh domestic stay together. Just a logical split.
  11. Well-Known Member

    I would suggest a Hager consumer unit (they do a double stack version) with a SPD

    You need to split your lights in to more circuits (46 items on a single circuit is a bit much), also consider having the lights near the consumer unit and to the exit on a dedicated circuit

    Where is the EV charger- it may be prudent to have a larger armour go to that area and install a secondary consumer unit for the EV charger / outdoor supply

    I prefer to install smoke detectors on lighting circuits if you do not it is harder to notice if they have tripped

    The SPD should go as close to the main incomer (the earth conductors should be kept as short as possible)

    Why metal conduit- better with plastic conduit

    Assuming the consumer unit is easy to access I usually put the appliance switches beside it (labelled)

    Have a dedicated circuit for the fridge (as already stated), you might want to have the router and patch panel on separate dedicated circuit(s)

    As others have said- ethernet points as well.
  12. Sparkielev

    Sparkielev Screwfix Select

    Ask for neutral to be supplied at each switch, either by 3 core or loop in loop out for smart switching
    Hoops-senior likes this.
  13. DedicatedDIYer

    DedicatedDIYer New Member

    Thanks all, I'll edit the specs with the following:

    - Fridge freezer to be on a separate circuit
    - Secondary CU for Outbuilding from a split tail
    - Switch and router to be on a separate circuit (I actually had this in the first version of the plan, but thought I was getting carried away with the number of circuits, probably have 1 or 2 more due to needing to split some of the lighting and socket circuits, this is one of the requirements, i.e. the electrician will need to confirm the safety of the specs and correct if needed)

    Any ideas how much all this will cost :)

    I'll be terminating all the ethernet, phone, and satellite cables and also setting up the patch panel and switch, the electrician will just route all the cables and do all the electrical bits. The property is also empty and will be gutted out so fewer obstructions.
  14. Bazza

    Bazza Screwfix Select

    Boiler/heating control wiring. The boiler will need more than a power supply. You might like smart control like Nest.
    Hot water cylinder - unvented? Will need additional electrics as well as an immersion heater for stand by.

    Don’t assume the plumber will/can do this!
  15. Banallsheds

    Banallsheds Well-Known Member

    A lot. Impossible to say any more without seeing the job or knowing where it is. Just ask some local sparks for quotes.
  16. DedicatedDIYer

    DedicatedDIYer New Member

    Just a combi hence a standard socket with isolator will do I think.

    It's in Redbridge, East London. It's a 4 bedroom property on 3 levels, ground, 1st and 2nd (loft). The outbuilding and the second CU will not be wired now, but need to lay the required cable and terminate safely for the time being until the outbuilding is worked on. I reckon it'll take max 3 weeks of labour. I'll be paying for the material, so I'll be looking for a labour quote. I want the job done to a high standard with no corners cut so yes it'll be expensive from that perspective too. But one thing previous experience taught me, not to skimp on the important stuff, structural, plumbing and electrics. If it's too expensive, I might train up as an electrician in 4 weeks and do it myself haha, that'll be the dream lol
  17. Banallsheds

    Banallsheds Well-Known Member

    Buying the material will mean the sparks won't get their mark up so they may increase the quote to compensate. More important any faults due to materials won't be covered by the sparks guarantee.
    sparky steve likes this.
  18. Bazza

    Bazza Screwfix Select

    I agree with b.sheds!

    I will never give a fixed price for labour if the client supplies his own materials. I have spent to much wasted time because the customer materials were not there when needed, or there were materials missing or
    ( most usually) just wrong and not fit for purpose.

    I just don’t take this sort of arrangement on. Last one I did was done on a time basis, not fixed price, for the above reasons.
    You won’t save money by buying your own. Any decent electrician will buy at discounted trade prices.
    sparky steve and Sparkielev like this.
  19. Well-Known Member

    Part of this scares me
    I don't like when clients get the materials- most usually get tat like BG / LAP and expect it to function like a top notch brand

    In circumstances like this I point the client to one or two decent wholesalers to buy their stuff, the wholesalers are explicitly told not to sell tat and the client benefits of better costs (they get better prices than a walk off the street)
    On high cost jobs like this it also helps keep turnover down.

    Be careful what outside lights you get- there are a lot of naff ones, so much that I have reverted to 10W LED fittings and photocells

    You need to zone the central heating to save costs- no point having the top floor on when nobody is there all day.
    Bazza likes this.
  20. ChicoTradesman

    ChicoTradesman New Member

    I appreciate that your comment about training up as a spark in 4 weeks is tongue in cheek but that is part of the problem with the construction industry. Bit of a tangent from what you are talking about I know but are there any tradesmen that have served a proper apprenticeship these days ? If you meet someone in Scotland who is in the construction industry and ask them what they do for a living the answer 95% of the time is plumber, chippie, spark, brickie etc. Ask the same question in and around London the same 95% answer “builder” possibly not on larger construction sites but it is definitely the case when I talk to people who do work in peoples houses. I have seen adverts in local forums where companies are looking one person who can do building, plumber and electrical works !! If someone came to my house to do plumbing work and then the same person turned up the following week to do electrics they would not get in the front door. I know a young lad who had no experience of the building game but got a
    Job as a labourer on a site. Six weeks later he is telling people down the pub he is a “builder” (when you could go to pubs). Tell me this “builders”. What apprenticeship did you qualify in ? Yes, some can turn their hand to several trades but the majority are.......well I won’t say but John Wayne was one.

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