ProDave

Just see how it goes with the sockets. Try unplugging anything that is currently plugged in, That will rule out a faulty item plugged in.

The basement will certainly have to be structurally formed as a basement and waterproofed. Others who have done a basement will have to comment if the insulation can be left until later. I see no reason it cannot be left as an empty basement with no details finished initially. Other money saving tips might be dirt cheap kitchen and rip it out and fit what you really want later. Outbuildings like garages and sheds can wait until later as can a lot of the landscaping.

We built the size of house we wanted. Previous house was 5 bedrooms that we ran as a B&B and we wanted to exit that business and have a normal 3 bedroom house. But we wanted ample sized rooms and we knew what rooms we wanted. Even so our 150 square metre "ordinary" house was not in the end very much smaller than the previous 5 bedroom house. Our key requirements were accommodation to suit our needs, and to be flexible, lower council tax, and lower heating costs than the old house. The site and available space on it led the basic shape and orientation of the house and which way was south and which way had the views (not the same) dictated a lot about the layout. Don't fall into the trap of building a massive house because you can. I wired a new build like that and when I went back some time later to do the garage, after the first winter, he was bitterly regretting building such a big house that he struggled to keep warm and cost a fortune in heating bills. Cost per square metre can be hugely influenced by careful purchasing and doing a lot yourself. e.g. a Howdens kitchen with a good worktop can be every bit as good as some posh German or Italian bespoke kitchen. But that leads into you can only ever have any 2 of the following : Good, Cheap, Quick. If you think you are going to be short on cash and might want to pause the build part way, one option our neighbour did was build a dormer bungalow but did not do the upstairs straight away. It was built with attic trusses so the basic structure was there from the start, but it was initially completed, signed off and occupied as a simple bungalow. It was some years later he then finished the upstairs and added the extra rooms.

Definitely separate the ring N from the landing light and make that connection safe in some form of junction box. Do that first and confirm the socket circuit no longer trips when you put the bulb in. then you have to find a N from the downstairs light circuit. A downstairs light fitting may be an easier place to find that if, it really depends on the house layout and construction and where is the easiest place to get a new cable down to from the landing light. It could even go back directly to the CU if that is easier.

Yes those are temporary supports holding up the back wall while they insert that big steel beam then it looks like they are going to knock out all or part of the back wall downstairs to join through into the extension. A structural engineer would normally specify that.

This is what annoys me about the attitude if this "electrician". HE should be checking things like that and he should have done so at least at the time of the board change if not before. His attitude of wanting to charge the customer £90 per hour to sort this out is making my blood boil. A quick check would be look at all the cables going into each rcbo, and if you see two of different thicknesses going into the same terminal, that would ring alarm bells. Lighting cables would normally be 1mm and socket cables 2.5mm, clearly visible as different sizes.

It's a tricky one. It has taken probably over 100 years for that end joist to rot out. A quick solution would just be replace that end joist having given the new joust lots of coats of wood preservative. you have solved all the easy problems on your own land. To do anything with that retaining wall is going to need cooperation with your neighbour and work on their land.

I thought the pink stuff was what goes in the flush water. The stuff you pre dose the holding tank with comes in green or blue, green being the less bad one. But it is years since I have bought any as it lasts so long. If you don't have drainage, you could always did a deep pit in an out of the way bit of your site and just pour it in there. Years ago that used to be standard practice on remote caravan sites, they filled it in at the end of the year and dug a new pit for next year.

Definitely sounds like he has borrowed the neutral from a socket circuit which is most unusual.

Buy the cheapest small touring caravan you can. It will have a toilet, a sink with running water and a water heater. You will need to fetch water to keep filling it's tank, but it will be far cheaper than hiring a portaloo and will give them somewhere dry to have a break etc.

So the hall light is switched from 2 different locations in the hall and the landing light is switched from ONE location in the hall and one switch upstairs? The issue I am sure will be in that switch with all the wires and tape. I am certain you will find it is taking L from the downstairs light and sending the 2 "strappers" (the 2 alternate switched L's) upstairs on a t&e. and upstairs, the landing light is getting it's N somewhere from the upstairs light circuit. That is the normal borrowed neutral scenario. And the solution is usually to take an extra N from the downstairs lighting circuit up to the landing light. BUT the fly in the ointment is you say it is a SOCKET circuit that trips when you put the landing light bulb in. Can you confirm that is really the case? Anyway if you want to test this theory, disconnect the N from the landing light and insulate the removed cable, then connect a temporary cable from the landing light N to the downstairs light N at the consumer unit.

Where is this third switch and which light does it control? the two posted above that appear to be the switches for the landing light?

That depends how competent you feel. At least you can point the electrician where to look if you want to stump up his fee to do it. It usually means rewiring the offending light, sometimes needing a new cable pulled through between the upstairs and downstairs light switches. If you want to have a go, post some pictures of upstairs and downstairs light switches with the fronts unscrewed so we can see the wiring, and the landing light fitting with it's cover unscrewed so we can see the wiring in that.

Do you want to tackle fixing this landing light fault yourself?

He has done a neat enough job of that board. So you have a "borrowed neutral" on the landing light circuit. The usual thing is the landing light get's it's L from the downstairs light circuit and it's N from the upstairs light circuit. But a socket circuit tripping suggests the original electrician was a bit more "inventive" with where he borrowed the neutral from. In any event some investigation and wiring alterations for the landing light circuit is needed. This will have been a pre existing fault, the only issue here is the electrician should have found this as part of his testing before the CU change. I think I would tell him to issue the certificate for what he has done, and find a different electrician to fix the landing light fault, one that is not going to charge £90 per hour.

There are several off there. Are they all tripping? Are they tripping individually or do 2 trip when you turn one thing on? Try and get a picture square on, and one with the cover removed. As it appears to all be "lights" that are tripping, I put my money on borrowed neutral (neutrals between one circuit and another connected)

Our cat flap enters into the sun room, which is an unheated room outside of the sealed envelope of the house. It lets the cat in to a relatively warm and dry place and we let her into the house through what is a good pair of external well sealed Rationel doors. One feature of an air tight house, is you can open one window or door without getting much if any through draught. So in practice but a sealing strip around the door from your utility room to the rest of the house, and you might find the fat flap does not swing wildly in the wind.

You need a new electrician. Shame you did not question this here before you gave him the job. He s only responsible for making the new, or altered circuits compliant with current regulations. The simplest way would have been to fit rcbo's in the existing board if they can still be sourced (i.e not an obsolete make) So what has he done? Post a picture of the CU as it is now. I am guessing a split load board with 2 rcd's? What exactly is tripping? One or both of the rcd's or one of the mcb's? Once I know what you have I can advise more. As for £90 to fault find his own work, the second word in my reply to that would be "off" To test for earth leakage faults you need an insulation resistance tester. As you are not doing this professionally so are not interested in a calibration certificate you can usually find one for not much money on ebay. But it is also very likely your fault is not earth leakage but a borrowed neutral, very common on old lighting circuits.

T&e is fine if not exposed, i.e straight through the wall into the isolator. Flexible conduit is often a better option from the isolator to the ASHP rather than SWA.

Check with your local regs and BCO. Up here it is a minimum of 1200mm by 1200mm flat in front of the door. One (presumably) 900mm slab would not be enough,

From the link to the smart thermostat: Safety Independent mechanical safety mechanism So I expect the thermostat housing contains a relay and the normal mechanical over heat cut out, so it would still comply with G3. But not if you start butchering it to give it a separate supply source.

Yes that is what is required, but I have a feeling the Tesla switch in the OP is not configured like that and would require a certain amount of alteration if it were even possible.

I expect with that limited space by the time you have got the flat area in front of the door, there won't be room to get the ramp straight out. So more likely you will then have to have the ramp sideways, i.e. parallel to the front wall of the house. That would allow you to just have steps from the front of the flat area down to the drive as well, so convenient for everyone.

Keep us posted. It is sometimes difficulty to keep a clear head and diagnose exactly what is wrong.

You need to be clear in what way does the pump not work? Does it just not pump, with power applied? OR does it keep on tripping the RCD so power does not stay on long enough to see if it works or not? Quite likely insulation breakdown on the cable causing earth leakage and tripping the RCD. You need an insulation resistance tester to check that.