Steptoe

Ah, OK, its sort of half normal to have 2 isolators, although you should still have one main switch that kills everything,

Errrm, I'm confused as to how you could possibly have (or why) you would have banks of RCBOs, or do you have a double decker board,? Or some other strange install,,,,,,,

He's using all RCBOs, so no 'banks' as such

Its only an opinion @Nickfromwales formed from years of using them long before the UK caught onto the benefits of them, same as RFCs, no one but UK (in reality) uses them as they are outdated too, Personally I only ever use SP RCBOs in very particular circumstances, But I most definitely would never recommend anyone using them in a self build, why save £100 on a >£50K job?

Yep, agreed @Nickfromwales But with a DP RCD when a fault trips, its isolated, and won't daisy chain every other circuit off, so perhaps less inconvenience, ? And, TBH, DP RCBOs are available at reasonable cost, I can actually source them for comparable price to control gear SP RCBOs, so its a no brainer not to use them , IMO. Yep, you could turn off the isolator to isolate, but you lose everything, working on upstairs lights, turn off RCD on that circuit, plug your handlamp into upstairs sockets, simples, working on upstairs sockets, turn RCD off and upstairs lights still work.

SP RCBOs don't disconnect the neutral, You can in effect end up with a daisy chain of a N-E fault on one circuit still leaking across the other circuits even when that RCBO has tripped, Causing other RCBOs to trip also. Not common, granted, but, I've come across it twice in the past ten years, also, SP doesn't, imho, comply if it is TT, Switching off a SP RCBO also doesn't imo comply with isolation of a circuit, SP RCBOs are a half ars*d method of thinking you are doing something better than fitting a dual or triple RCD unit. Oh, and don't get me started with what happens if you end up with a reverse polarity on the incomer, it does happen,!!!!!

I just think radials are much better, Less inconvenience under fault, Less cable, Less labour Safer Why have a cable that can only carry 27a (under ideal conditions) when you don't need to,? Tip of the day, why the smokes are on us lights,? Feed to ds smoke, 3c to upstairs smoke, t&e to us lights from us smoke, less cable, less labour, Oh, and again, do NOT use SP RCBOs,

Oh, and check if it needs a C type breaker, depending on length of the run, you might need 4mm if that's the case.

Armour flex is what I fit, done 100s of them, (YY or SY depending) Make sure you gland it properly with pig tails, its not that hard really with the proper glands.

Personally, Bedrooms on 2x 16a radials, Living room on a 16a radial, garage, C32, (what about that welder?) Smoke alarms with U/S lights ASHP prob needs a C as well Be careful on your selection between Bs and Cs, makes a big difference. Just a thought,

@JSHarris Its still C&G , I did mine at 15th too, And, you don't have to be a member of a scheme to be competent, there are LOTS of people that are members that are most certainly NOT competent, The schemes/scams only operate for domestic properties in England and Wales (mostly), I'm only a member as its stupid not to be and keep turning away domestic jobs when proper work is a bit slow, plus, I started doing a lot more renewables, solar (thermal and PV), heatpumps, and biomass, If @TheMitchells already has most of the equipment and paperwork required I'd say it makes sense, I did say budget at least £2K if they needed the gear, even to get BC to sign it off requires so many site visits (1st fix, 2nd fix, and in between) and expense (round here its in excess of £400) , its usually unviable for most people, I'm registered to sign off 3rd party work, but I point blank refuse to do it, I think most registered installers refuse to, its a very bad practice imho, that's the problem that BC have, no one will do it for them. Personally, I couldn't wire a 3bed house for £1400, I did one recently for a mate and labour only was £1800, so you got a good deal. Oh, BTW, absolutely nothing wrong with an AVO, I have an AVO7 that gets used almost weekly, I do a lot of fault finding, actually, I have 2 of them, but one needs a battery......

Is a night vent not where you can open the window a crack, turn the handle back and lock it again,? So the window can't be opened any further. I don't know, but you can do that with the windows in our house .

Buy a short stem valve dor tubeless tyres from a motorbike shop, drill a suitable size hole in a piece of 22mm (or bigger if you can ) pipe, shove the valve from the inside out, Make sure you get a short stem valve,

OK, all good then, Does he have professional indemnity,? It would surprise you the amount of people don't have it. BTW, I don't think your build insurance will cover it, I could well be wrong, but I'm fairly sure it needs to be a standalone policy. I'd definitely recommend Stroma, very well suited to me at least, and geared up for the small one man band type firms, Give them a ring , they are very friendly, based in Yorkshire (iirc) They'll send you out a welcome pack with everything you need to know, I used a job that was started in 2007 and still not finished for my first inspection,

BTW There is no such thing as being partP Part P is a part of the building regulations that you must comply with. If you don't meet the requirements, or have to purchase the stuff mentioned above, Budget on spending at least £2K, Depending on your history and recent experience, PL insurance could be anything from £50 -£500 for £5mil PI could be anything from £100-£2000 for £250K

Thanks @Onoff Yep, I'm with Stroma, was with niceic previously, Just the same, for half the price, kinda, Stroma are a bit tighter with if you are actually competent rather than just has your cheque cleared, If you have all relevant paperwork, inc 2391, or whatever its called nowadays, 17th 2382 , calibrated test kit, up to date books, lock outs, etc etc, the usual that they all want, and at least 1 major job to show, within last 6months iirc, 2mil PL , you will also need professional indemnity , as you will be designing the install,

I'd agree with @Nickfromwales Its the same amount of labour, and not much more expense, If you do decide on a socket, remember it must be UNswitched, Personally I have my boiler on a plug and socket, if there is a power cut I can plug it into the Genny so at least I still have heat.

A quick note @Ferdinand Those are only Single Pole RCBOs, IMO not really fit for purpose tbh, You can get daisy chain faults as the neutrals don't disconnect. And, totally not permitted on TT systems, only can be used on TN, I'd advise anyone considering using RCBOs to ensure they are DP,

A heating appliance (which an oven is in effect) over 2KW should be on a dedicated circuit.

I'd also tend to split up the sockets more, perhaps 16 or 20 amp radials, and just use rings for the kitchen / utility areas, Rings are a dark ages legacy from when there was a copper shortage.

Are you using Double Pole RCBOs, ? Oh, and I'd have the smoke alarms on with one of the lighting circuits, just a personal preference of mine.

Piranha nuts still require the gland to be made off in the same way, they are really useful for glanding into a non metallic box though, where a normal gland and nut is of no use. Its also very common to see the wrong type of glands used, and glands made off incorrectly. Even by so called electricians, the amount of times I've saw BW 's used when it should have been CW (IP rated) , and also quite often CW made off incorrectly, External supplies really do require a decent understanding of earthing and how to terminate the proper cables properly, its not really a diy job IMHO , beyond perhaps installing the cable as instructed by your electrician.

Co axial power cable, LMFAO,! A little knowledge and all that, ,,,,, Concentric, or split concentric will not be within BS7671 for a domestic install unless you use a deviation and can justify it meets or exceeds BS7671, so not really a DIY job, SWA can be buried direct if trenched, and bedded correctly, NYY cables and all other forms of armoured flex and Hi-Tuff need to be glanded correctly, which is no easier (or harder) than SWA tbh, but, very very few people ever gland any of these cables correctly, also, if you have a PME supply, you MUST have permission from the DNO if you wish to use their earth outside the equipotential zone, I've never once heard of them grant it, You can always wing it, lots of people do, but it would only takes the one fatality to be at your own place.

its at the door, open it up, big massive BFO fan and jobs a goodun,

ah, OK @IanR I've never actually used it in a building scenario, but have used it loads in motorbike pure road racing, never seen stuff like it, its so good, but, NEVER paid that sort of money for it, how much do you realistically need? it may be cheaper to buy it for a different purpose, as in when you buy flowers, as soon as you mention 'wedding' the price tenfolds.