ProDave

What is wrong with a wet room because you have young children? Make the whole room a wet room, and do as we have, the 2 screens around the shower in that corner hinge away flat against the walls when the shower is not in use leaving a huge open space.

So you already have RCD's in the CU. So I would be looking to verify the cable routing from the meter box to the CU to confirm it does not actually need RCD protection and swap that for a plain MCB in the meter box not an rcbo.

Get an electrician. It might not even need RCD protection on that cable depending on it's routing. Post a picture of the consumer unit in the house as well.

That's an RCBO I bet it is earth leakage tripping it, damp somewhere. How does that connect to the house? what sort of cable and over what distance? Do you have any test equipment like an insulation tester?

Post a photo of this "main trip" so we know what it is.

Always good to get that completion certificate.

That is just over thinking what will the PV power? On that dull day, it will power whatever happens to be on in the house at the time, and if there is any surplus after that it will divert excess to the immersion heater. It needs no user input to achieve that. So the key thing with solar PV (without battery storage) is move as many of your electrical loads as possible to the daytime. For instance I have my ASHP timed to only start DHW heating at 11AM. By then the sun should be up and PV generating. So at least some of what the ASHP is using is coming from the PV. And all big appliances get used near the middle of the day. And there is nothing wrong with the ASHP heating the DHW AND surplus going to the immersion heater as well at the same time. PV conflicts with a TOU tariff such as E7. The TOU tariff suggests you want to do as much as you can at night, PV says do as much as you can in the day. I don't personally like TOU tariffs, they come with a much higher day rate.

Ditto to the above. You need a LOT of insulation under UFH. There simply is not any easy retro fit on top system that will give good results.

Our low energy 150m2 house is using 1000kWh per year to heat DHW and 1500kWh per hear to heat the house, both measures are electricity consumed by the ASHP. So £280 for DHW and £420 for heating. We did once go away in winter and came back to the house at about 12 degrees with no heating and no people in it for 2 weeks. So even with incidental heating from occupying the house, I doubt it would be comfortable with no heating at all.

I guess it depends where you are. Up here in the Highlands no passive house will be comfortable in winter without any heating. My ASHP bills are not huge, and it is completely controlable including OFF

What make are the windows? I think, if you put an allen key up through the bottom of the hings pivot, you will find a grub screw there, that you can turn to jack the door up and down.

This if course is the advantage of a really well insulated house with a low decrement delay insulation. It just never heats up or cools down so quickly that you need to alternate between heating it and cooling it in the same week, let alone the same day.

What is the internal wall made of? Stud wall easy to recess a CU, single skin brick internal wall much more challenging to recess anything. The much larger job will be connecting all the circuits to the new CU.

Yes, a case of "be careful what you wish for (equality)"

Sorry but why should the WASPI women be compensated? The gist of what I am hearing in the news, is in spite of the change in SP age being announced many years before it came into effect, some are claiming they were not notified and it came as a shock to them and they had no time to make plans. do these people live in a bubble never watching any news or reading any newspapers? Nobody notified ME personally that the SP age for men would rise from 65 to 67 so I have just as much of a "claim" as the WASPI's

I remember the 18 months we spent in the static, which happened to include the winter with the "beast from the east". It proved it was possible, just, to survive in that in a winter storm but boy it needed a lot of heat. We lit the stove in November and it hardly went out until March and it was a challenge keeping up with firewood to feed it. Now I read of people in "ordinary" houses with high heating bills and sit smug in our comfortable house with low bills. It is definitely worth it. It is widely assumed by most that your largest household bill is energy. It is most certainly NOT in our case, it is council tax, and sadly that is one I cannot reduce by making any changes. I have said before, if you applied the same criteria to council tax as you do heating bills, then we are in "council tax poverty"

Well we keep being told that automation etc will make us all more productive and increase leisure time. I have been fed that mantra since school and I am still waiting for that to be the case. But it should be possible. Time for those that kept on telling us that to prove it. It won't be my problem, and not my daughter's either so I won't worry about it.

What sort of property needs two 24kW boilers? That's 48kW of heat? This is clearly not your average house. Clearly cost (running cost) is not an issue to the owners so just slap in your electric boiler. Unless you find they already have three 10kW electric showers and the electric supply is also already overloaded.

You surely did not ask for a new gas connection with a new meter and a new set of bills just to heat a garage conversion? Just connect it to the house gas supply. The extra load is not going to bring the grid down. Or just the flow and return from the existing heating system, unless there is a huge distance from house to garage.

I have always held the view an electric boiler is a solution looking for something to solve. If you are going to heat the house with electric resistance heating, just fit individual panel heaters, controlable room by room. An electric boiler just adds complications and cost to achieve the same aim (if you are lucky) of heating the house by direct electric resistance heating.

I think "starting" for planning is separate to "starting" for building control.

Are they trying to justify that on the basis the development has already started thus changes to BR's since they started do not apply? It will be interesting to see the legal ruling.

Making such alterations to a CU is usually frowned upon. If you are going to do it the usual way (that the manufacturers do it) is one cable daisy chaining from one to the next so no more than 2 in one terminal. Manufacturers tend to use fine cored cables for that, not the normal "meter tails"

I have a "conventional" UFH setup. a normal UFH manifold with a temperature blending valve and circulating pump. There are only 5 pipe loops on 2 zones downstairs. I have yet to find an issue with this setup. Beware that many heat pumps require quite a high flow rate and their own internal pump on it's own may not be able to achieve that (mine could not) so I would not be in a rush to ditch the manifold circulation pump. Arguably with the ASHP setting the flow temperature for heating you might say the temperature blending valve could be omitted but what about when the ASHP switches from DHW to heating and that slug of 55 degree water in the system would get sent round your UFH loops. All my loops are on 200mm pipe spacing and cover up to 8 square metres, so your 15 loops for 150 square metres sounds reasonable. I would be looking for no more than a 6kW ASHP for your heating load.

When I was doing our build I looked into the law on this as there are 11KV overhead lines across the road from us. You will often find a statement "no building within 10 metres of overhead power lines" When I looked into it, it turns out the 10 metres is the point where you need to start taking notice, serious notice of the lines and the actual restrictions only start at 6 metres from the lines. We also had more than one delivery refused to use a HIAB as they deemed it too close to the lines, others just took more care knowing they would be slewing away from the lines. Nobody is going to install insulation on a live 11KV line (like they to on a live 240V line) so even if some insulation was available it would be a shutdown of that section of line