ProDave

That does seem ridiculous. Mine is a monoblock unit so there is water flowing between the inside and outside, so it is indeed logical for it to turn on the circulating pump to prevent freezing. Even that it is just the circulating pump running at normal circulation speed, so just a very low level hum, no worse than at any other time of operation. Even with mine, where you have antifreeze / inhibitor mixed it, there would be no need for the frost protection to kick in until say -5C?

I recall Jeremy when preparing to sell his old house, presented a record of all the improvements he made to the old house including some photographs and the assessor completely ignored it all and just did the standard RDSAP assesment. Do let us know if you find one that will listen to and look at your evidence, you certainly want to check he will do that before you appoint him. I have even heard of people with a new build, with a proper as built FULL SAP, when later wanting to sell, that original SAP is deemed "out of date" and they are forced to get a new one which is done as RDSAP and comes out very much worse. If that ever happened to us, I would just give buyers a copy of the original full SAP and tell them to ignore the recent one. The system is a joke, particularly as the majority of buyers (except perhaps landlords) ignore it.

Invite an engineer to spend a night, make them a bed in the spare room, and then they might finally hear for themselves what the issue is. I don't see any other option if this odd noise does not occur at any other time of day.

Re living on site in a static. Strictly you should ask for temporary PP to do so as part of your planning for your final house. You pay Council tax and band A and in our case for the council tax list (and also for the electoral roll) they prefix the address with "Caravan"........ How much and what size are the plots? I would me more interested in the proposed drainage arrangements. That is more likely to cause issues than broadband speed. If wired landline broadband won't work, you might be able to get 4G mobile or (at more cost) satellite broadband.

Seconds to remove them. A bit longer to re fit them if someone has moved them from where you carefully placed them correctly oriented, and you have to work out which way round they go once more.

We have a Lamona oven (Howdens own brand, god knows who actually makes it) and SWMBO finds the side grills impossible to remove and re fit so I am always tasked with that job.

And what was left on standby? Televisions, computers, broadband router, set top boxes, Fridge / freezer left on? Or was everything unplugged?

Under mount sink implies stone or imitation stone worktop. There are 2 ways to mount an undermount sink and some stone suppliers will only use their preferred method. One is support the sink independantly in the base unit e.g. with a wooden frame and supports and the stone worktop just sits down onto this. This method might just work in your narrow base unit. The other method is the sink hangs from brackets bonded to the underside of the worktop. This requires space all around the sink on all 4 sides and needs the bigger cabinet. So first talk to your stone supplier.

A shade over £5K for a new one, from a random chosen site so no doubt you could get cheaper https://www.thenaturalenergycompany.co.uk/shop/index.php?route=product/product&product_id=297 Buy a new one and keep the old one for spares?

After the test I realised I had not taped up the Tundish that vents the UFH cylinder so there was straight away a 22mm copper pipe leading out of the building. I wish I had remembered that and taped it up.

What has gone that costs £1500. Add that to the £2500 already spent on a new compressor and that's £4000 for which you should have been able to just buy a new heat pump (unless it was very large)

I meet a lot of joiners / carpenters in my travels, but so far I have only met one i regard as good enough to work on my own home, and he did some of my kitchen fitting and jung some of the doors, which he made a very good job of. I define "good enough" to work on my house as capable of doing a better job than I can, and it is saying something when a lot of the joiners I see I don't think can do a better job than me. But just moving a hinge over by a few mm is a difficult job. I would have altered the door stop and taken the hit on re painting after that,

I am no fan of the concept of an open plan kitchen / "family" room. For a while while we were "in build" we used that room as a living room and it really really really irked me when the fridge / Freezer fired up. You just do not want that sort of appliance in what is supposed to be a living room. Now we have all but finished I love the separate and quiet living room and regard the other room as what it really is, a kitchen / diner (though it does have a sofa and tv for when we want to watch different things)

And if it is above that rate it would probably fail BC anyway? Ours was 1.4 and I was hoping for lower.

Do you have a measure of how much electricity the heat pump is using to heat the house in a year? There are 2 measured of flow temperature that we need to know. One is the flow temperature of the water coming from the heat pump. This will be the higher figure and will need to be reasonably high to run the upstairs radiators. you should be able to read this from one of the parameters on the controller for the heat pump. The second is the flow temperature into the under floor heating. Usually on the UFH manifold there is a blending valve that sets the UFH water temperature, and a little thermometer on the manifold to show what the temperature actually is running at. This is easy to increase a little by adjusting the blending valve on the manifold.

I believe it is required to confirm the ventilation rates are adequate (whether mvhr or trickle ventilation) and ensure CO2 levels do not get too high. I don't have them as my building warrant pre dates that requirement but when I first looked for one they were very expensive. I would hope now all houses have to have one they will be somewhat cheaper.

A colour blindness test was part of the medical before I could start my apprenticeship.

The garage part does not need any insulation. So you don't need to dig deeper.

Scotland has been set in the ways of timber frame for decades. So TF is "how we do things up here" But that does not mean it is the ONLY way, it means anything else most builders will consider "unusual" I can't see a problem with lack of bricklayers, after all if they can find them for the outer skin why not the inner. Perhaps they don't trust BCO to pass it and don't want grief, but again up here you need a building warrant which is akin to "full plans approval" in England. So if it's on the plans and BCO have approved the plans and it is built to the plans, BCO will pass it. I know of a pair of new houses built in Lairg a few years ago that are built entirely of cavity brick and block with no TF involved, because that is what the (English) customer insisted on.

If the architect cannot understand what the BCO is saying, you have the wrong architect.

If the extension is part store and part garage, you would have the store bit level with the rest of the house, and the garage bit 100mm (or more) step down from the store for reasons already mentioned.

Not long after the new colours came in I found I could sell lengths if red & black removed from a rewire on ebay for more than the cost of new cable.

I was going to ask just where do you expect to get the fuel from.

Double check valve required in Scotland by Scottish water, which must be an admission the single check valve incorporated into the boundary box that they supply does not work

It is true that a 3 phase board cost a lot more than a single phase board, but the way I would tackle it is just fit a single phase board now. you can add a second or change to a 3 phase board later if you need to.