andyscotland

I guess maybe @SteamyTea was thinking regs might be different, but this is just BS7671 which applies UK wide (not France though 🤣). I'm not sure why the electrician didn't like Wagos if they were in a proper containment (other than that some people don't like new things). When installed per manufacturer's instructions in a wagobox they are certified for use even in a totally inaccessible location (unlike anything with screw terminals). And are very hard to get wrong (again unlike anything with screw terminals). They do need to be in a proper box to provide protection for the unsheathed cables and strain relief, among other things, and the cable tie to hold the box closed is also important. I would definitely use a wagobox to repair that damaged section, ultimately even if it's not the cause - and it could well be - it needs to be repaired anyway. Hard to see from the photos how far it is to the junction box, if it's not too far best/cheapest bet is probably just one wagobox and then replace the whole section to the junction box. Alternatively get 2 boxes and just splice in a short replacement section. Make sure the cable you use matches or exceeds the size of the existing (I'd assume 1.5mm² will be fine, but check). Unless you have a spare bit of suitable old cable lying around for the repair you are going to have different core colours in the replacement section. Old red = Brown, Old black = Blue. You should therefore also have a label like this at the origin (you can make your own) - not that there's really any electricians out there who aren't well aware of the harmonised colours by now! Technically speaking as this is a repair to the fixed wiring it is Minor Electrical Works and should be done by a competent person, properly tested (with calibrated test equipment) & documented.

Ah, I'd misunderstood the original pic. So I assume the circuit that feeds the suspect light is also on the left hand half of the board? That would make sense. Top one would be fairly unlikely to be causing this type of fault (but should obviously still be fixed, for safety). Bottom one would be a candidate as there is a copper pipe nearby and if the exposed neutral contacted that (or was bridged to it by moisture) that would be exactly the type of trip you're getting. Worth checking, but equally if we have now established that's on the other half of the board to the RCD that tripped then it is probably not the culprit in this case.

30 milliAmps I assume. The thing is the RCD is across both the sockets and the lights so that would not necessarily matter. But if still tripping then sounds like that's not a factor. The red switch is just a switch so it won't have been that. If it was caused by the light it should have been the RCD (the black one with a test button) on the right of the board e.g. furthest from the red switch as that is the one that protects the half of the board with your lighting circuit breaker (the one that is switched off). It is possible for 2 RCDs to trip simultaneously - the tripping current and time are both so low that they trip easily and fast. Opening the circuit is a mechanical action so it's rapid but not instant. So the downstream can detect a fault and start opening but the power remains connected for enough milliseconds that the upstream also sees the fault. Ideally an installation would be designed to reduce the risk of this happening but it's not always possible (and even with the best designs can't be guaranteed in all circumstances). Depending how your lighting is wired, I would also check any cable from the suspect lamp to the next fitting. And also look out for any junction boxes nearby and similarly check them for dead things/damp/visible damage. Make sure you de-energise the circuit at the distribution board before you start poking around, especially as there is a chance of damaged/wet connections. And if there is anyone else home who might be tempted to turn circuit breakers on, tell them what you're doing.

@saveasteading just to be sure I've understood: the box marked DB3 that @G and J has marked up is at the origin of your supply, and the power is fed from there to the multi-way split load board in your final photo? And the trip that is going is the one G&J has circled red, knocking out the whole system? As @G and J says, that one is an RCD and will trip on a very small imbalance between the current going out on the phase (live) conductor and coming back on the neutral. It's not possible to see in the photo what rating that is, it will likely either be 30mA or 100mA. The one you have marked/switched off in the downstream board is an MCB and will only fail on overload (likely 6A if it's a standard lighting circuit). Therefore you have a fault that is causing a very small amount of current leakage. This means either a high-resistance short between phase and earth (e.g. a mouse body, or degraded insulation) or possibly a dead short between neutral and earth : the neutral is not quite at zero volts so connecting to earth will cause a very small current to flow. Assuming you haven't recently made any changes to the system, and have tried removing/replacing the lamp itself then the most likely explanation is either recent cable damage, moisture ingress to a connection point, or failure of a connected electronic circuit (which sounds unlikely if you have isolated it to only happening when a specific light is switched on even with the lamp removed). There could be a couple of reasons why it is tripping at the origin rather than at the RCD protecting the right hand half of your downstream board: * Possibly, both RCDs are 30mA and the same type. You would generally try to avoid wiring RCDs in series like that because there is no guarantee which will trip first on a fault. Usually I would either try to run cable between boards in a way that means it doesn't need an upstream RCD (eg using steel wire armoured cable) or use a 100mA time delay RCD upstream to increase the chances that the downstream RCD trips first. However it is not always possible/allowable to do this and so you get the nuisance that sometimes a fault will trip the whole installation. * It may also be that the lighting circuit itself is only producing a very low leakage but there is leakage elsewhere in the installation which means when it all adds up at the origin it is just enough to trip the RCD. It's common for electronics (computers, LED drivers, smart stuff) to produce a small level of background leakage due to the way electronic transformers work. In fact it is even possible that the lighting circuit has always had some cable damage causing leakage but only recently have you connected more electronics elsewhere and so it has now become a problem. Ultimately the only thing you can really do is get a proper insulation resistance tester and try first to isolate whether there's any part of the system with a lower-than-expected live / neutral resistance to earth. You will need to be very careful to disconnect absolutely everything electronic before testing to avoid damage.

It actually did pretty well at that until it got to the certificates question, where it is completely wrong (but to be fair a high number of humans including accountants also get this wrong). For new builds and conversions to "dwellings" no certificate is required nor should one be issued (VAT 708 Section 17 and the definitions in 14.2-14.5) In those cases HMRC expect the builder to know what they are building/supplying and how that type of work should be rated for VAT - in much the same way they expect a shop to know whether they are selling biscuits or cakes. The certificates are for cases where the building would not normally be zero / reduced rated, but the customer is entitled to a lower rate because they are a charity or are building a care home / hospice / etc. In that case it's for the customer to prove to the supplier that they are eligible and the certificate is part of that.

You've probably solved this now but thought I'd add a couple of details for anyone that finds it in future. First, I'd echo @Mr Punter's recommendation that you should discuss this with your spark - once you start departing from the standard circuits, cable sizing & de-rating can be complex and depends on a lot of factors (e.g. supply earth arrangements, circuit lengths, protective device selection) so the right answer will depend on the specifics of your installation. The starting point in BS7671 is 523.9 which says that cables "shall, wherever practicable, be fixed in a position such that it will not be covered by the thermal insulation". So it will usually be better - for any loading of cable - to use a service void, or notch studs rather than drilling the centres. If that's not possible for structural / mechanical protection reasons then your suggestion of clipping the cable out to the edge of the stud, across the face of the insulation, and then back in to the hole in the next stud is the next best. That does assume you can safely extend the length of the circuits without causing knock-on issues for things like voltage drop or loop impedance. If you can achieve that, that gets you into the territory of installation method 102 for T&E cable in a stud wall where the cable is touching the wall surface (though there are some caveats depending on the exact materials). Table 4D5 gives the current carrying capacity for those methods. That allows 13A for 1mm², so a 6A lighting circuit should be fine. For 2.5mm², the rated current in the table is 21A - assuming the ring you mention is a standard 32A socket ring final, regulation 433.1.204 states that the cables must have a current carrying capacity of not less than 20A so again that's just OK. So long as the loops into the stud centre and back out are touching the stud, and are short, I would not count them as being "totally surrounded by thermal insulation" and therefore they don't require additional de-rating. I don't think 7671 actually differentiates between an interior or exterior wall surface, but working from first principles I'd say if you can take the cable along the outside wall (especially if you can clip them to the OSB) that would give you more of a safety margin as both the stud and the surface will obviously be colder than the inside wall, giving the cables more chance to dissipate any heat that builds up on the short loops into the stud centres. If you can't go in and out, and have to run through the centre of the insulation, then you would be looking at installation method 103 - T&E in a stud wall not touching the surface. Table 4D5 gives 8A for 1mm² so the lighting would be OK, but 2.5mm² can only handle 13.5A in that setup and you would have to go to 6mm² to meet the 20A requirement for a 32A standard ring final. At that point I would probably look at alternate circuit designs / protective device sizing as although theoretically you can get 2 x 6mm² into most socket terminals it is a real pain. If at any point the cable is totally surrounded by insulation then you would need to de-rate for that - by 50% if it's surrounded for more than 0.5m, or on a sliding scale for shorter sections. Again, this is really intended for background information to assist the discussion with your spark.

When you isolate individual circuits, you are only isolating the phase (live) conductor. The neutral remains connected. If other circuits in the installation are energised, there will be current flowing in the neutral. This, combined with the resistance of the neutral, means that the neutral will have a small voltage difference to earth/the neutral at the origin. Normally that doesn't matter because the current can still only flow along the neutral and through the RCD. However if you touch neutral and earth together (e.g. when cutting a cable) this creates a parallel path which will allow some current to flow through the circuit you have created. Since this bypasses the RCD, it causes an imbalance and causes it to trip. Time delayed RCDs - like all RCDs - still display shorter tripping times as the current increases above the rated value. For example a 100mA S type RCD at 500mA is allowed to trip in 40ms - a lot less than the 130ms minimum with a 100mA current. If you had a phase to earth dead short then the current imbalance was likely into the hundreds of amps, and therefore well outside the parameters the time delay was specified/designed/tested for, so all bets are off. The time delay is really for situations where e.g. a human is in the loop, rather than cable shorts.

Bear in mind that once they get planning, they have planning, and can build regardless of whether they honour your agreement. A legally binding agreement is only useful if you trust them to honour it, or have the means and determination to force them to through the courts if they decide not to. And even then only if the developer doesn't disappear/go bust first - are they a big established firm? So I'd think carefully about what you want here. If you're actually OK with the development but this is a nice opportunity to extract some benefit while you can, then perhaps accept the risk it might not happen. In that case not worth spending money/time on solicitors. Just get the developers to document the offer - including dates - in plain English on their company paper and get it signed. That's still "legally binding". If it's more important to you, then you need a contract where the penalties for them not complying are definitely big enough to make it worth suing. Otherwise if it's just an agreement to do a few £k of work for £1k, you may later find it's not worth the legal fees & risk to try to force them to deliver. For that I think you do need input from a solicitor working for you, not them, although you should ask the developer to cover the cost (ideally upfront).

I think there's a bit of headroom. As Octopus explain it, on Tracker & Agile essentially the customer is taking the risk - but that cuts out both the risk & importantly cost of hedging that the supplier (and their middlemen) would otherwise have to do to give you a nice stable price all year round. If you need the certainty of knowing what your bills will be day to day and month to month, a chunk of the "electricity" you're paying for is actually risk premiums, interest & reimbursing brokers for the hedges they made a loss on - and as I understand it a good chunk of that will be external to Octopus. So I guess like most things financial, if you're fortunate enough to be in a position to gamble a bit with cashflow you can probably make savings over the longer term without hitting Octopus' margins and everyone's happy...

It would definitely be worth comparing Octopus Agile in that case. When I looked at the end of last year, Tracker's daily price seemed to work out a bit cheaper than the average (mean) of all the half-hourly prices on Agile for that day. But I think Tracker is essentially using a weighted average based on when people generally use power, where Agile is using the raw wholesale price (simplifying a bit). If you can control time of use, particularly if you can avoid the ~ 4pm - 7pm surge then I worked out you could do better on Agile's half-hour pricing. Don't have the analysis I did to hand just now, but for example looking at today's Agile prices for Southern Scotland, overnight is around 14-15p, rising to 20ish for most of the day & evening, with a couple of hours around 38/39p at teatime. And overnight prices this week seem quite high, before Christmas we had several days where overnight was dropping to a couple of pence a unit or even in some cases a negative price. So if you're able to control water heating etc to use the optimum time window each day I think you'd easily beat your current 16/34 E7 both at night and for almost all of the day. Will try and dig out the more detailed data I did in December when I'm back at PC.

I don't know if that's a huge issue, it seems fairly easy to set up an HMRC login these days (and some people will already have one). I don't have any special info but it wouldn't surprise me if they take the same approach as for Charity Gift Aid claims - upload a spreadsheet with known column headings and data formats (or download a template from them and fill it in). It's hugely cheaper to build a system to parse and validate the content of a spreadsheet than to build one that can support line by line data entry and the likelihood of people needing to do it in more than one session - unless there's a need for variable/complex types of fields on each individual item. This is a huge bugbear of mine (as a software developer). None of the cloud accounting packages are anywhere near as fast to use for bulk data entry as the older desktop packages. They have other advantages, of course, but for "power users" they can be painfully slow to use!

I'd definitely suggest numbering every document as I assume they will still want a detailed schedule of the individual items you're claiming. However from the sounds of the announcement so far it might be numbering every document & putting them in a lever arch file in case they ask for them later, rather than having to scan them all. Which would be good. I wonder if they've done a cost-benefit analysis of how much time they spend checking all the individual invoices Vs how much they save in amounts they reject from the claim, and decided it's cheaper to take it on trust with a bit of audit/targeted inspection as for normal business VAT claims.

Just seen this highlighted on a tax & finance email I get, and couldn't see it mentioned here yet https://www.gov.uk/government/publications/vat-diy-housebuilders-scheme-digitisation-of-claims-and-extending-time-limit/vat-digitisation-of-claims-and-extending-time-limit-for-diy-housebuilders-scheme From 5th Dec 2023 apparently: * The time limit (I think for all claims) will be 6 months from completion, not 3 * There'll be the option to claim online (which presumably will also let you see status etc) * They will apparently no longer require all the invoices at the time of submitting the claim. I assume that will put things on a similar footing to businesses, where they might inspect some claims/ask for a random sample of evidence, and potentially impose penalties etc if they discover you've claimed something you shouldn't have - they don't spell out exactly how that will work. So would still be important to make sure you have & have checked all the invoices, but no longer the need/risk to post off all the originals to HMRC and hope they arrive...

That would turn it into a hybrid roof, which can be risky. You would need to do a u-value calculation & condensation risk analysis to make sure that the joists & OSB stay warm enough to avoid any condensation within them. A small bit of extra insulation may be ok, but I'd want to be confident I had a good undamaged VCL below the joists was not punctured. If you were doing that and therefore adding a VCL below joists, I'd go with your idea B but you probably don't need to fuss about taking it up the joists a bit and the extra staple holes that will create. Just let it drape down when fixing so you have enough slack to push it upwards to sit on services/downlights where needed. Assuming you pre-cut downlight holes before the plasterboards go up and use LEDs / a cap to prevent heat damage to the membrane. If you go that route, just take services up and down the joist gaps and go across at the top of the wall if needed, to avoid having to notch anything.

@TerryE be interested to hear how you get on if you do explore it. ASHP is on my list for the future (just living in hope our existing gas back boiler will survive till the current projects on my list are complete & my wife has recovered enough to let me start a new one 🤣)