ProDave

What are your ground conditions? You will need to be digging a 2 metre or deeper hole to install it. Will you be likely to hit rock? Will the hole fill with water due to a high water table? These might influence which one you fit, and HOW you fit it, i.e it may need to be concreted in if a high water table. This is what you want to be discussing with your supplier / installer. If he just comes back and says "I always fit this one" ask him why and what is so good about it. There are a few other options if you have a bedrock problem and can't dig deep.

Here is a good place to see many of the alternatives, though this includes the "mechanical" ones as well https://www.drainstore.com/sewage-treatment-plants/

ALL septic tanks draining to a watercourse need to be changed to a treatment plant by the end of 2019. I am surprised there is not more publicity about this. Whatever you do, don't buy a treatment plant that has moving mechanical parts down in the smelly stuff. Trust me, you won't want to be the one changing the motor or belt WHEN it goes wrong. Instead choose one that works with an air blower. There are several now to choose from such as the Biopure, Conder, Graff, Vortex and no doubt many others. The air blower type do also seem to have the best / cleanest effluent of all treatment plants. I paid just under £2K for my conder, which looks very similar in design to the BioPure. In Scotland you would need a building warrant to install the new treatment plant, I don't know if that is needed in other parts of the UK. At least one member on here has a treatment plant draining to a dry ditch and building control were happy with it.

Well I am well known for being differerent We have standard 2440mm ceilings downstairs, but it's the bedrooms where one gets the full vaulted ceiling with a mezanine, and the other gets a 3M partly vaulted ceiling (so we at least have a small loft space above for storage)

No, pre heating water in an open header tank to "warm" is a very bad idea. Use it to pre heat in real time, the cold water entering the hot water tank.

I did mine all with a bull float and got a pretty good finish. the key is to keep working it as it goes off. A replacement swivel mechanism is £150 so half the cost is just that bit.

Can you hire one? I used one for my concrete. Be prepared to spend an hour or more working it to get a decent finish.

VIP Airport lounge?

Not with my windows it doesn't.

Don't forget outward opening can also be of the "tilt" variety, outs tilt from the top and you can lock them open on a ventilation setting so you can get fresh air and still be secure.

Another comparison. We have had unseasonably cool weather for a MONTH now. I doubt the average temperature has been any higher than 10 degrees, it did get to 20 one day, and below 0 one night. But even with no heating we are still maintaining 20 or a little over inside the house, and for the last few nights have slept with the bedroom window open for a bit of a nigh purge to keep the upstairs cooler. Like others have mentioned before, solar gain via the west facing windows in the evening is the most noticable when the clouds have the grace to depart for a short while. We don't get much solar gain on the south elevation because of the trees.

Re solar PV Vs Solar thermal. Solar thermal is a one trick pony. Once your tank is up to temperature (hopefully a bit less than boiling) any more energy it could produce is wasted. Solar PV on the other hand can power anything electric, So the normal system of an automatic diverter to send excess power to the immersion heater, favours the generated power first being used by anything in the house, and only heats water to prevent it being exported to the grid. I think it was my HW tank we did a legionairs analysis on. Our drinking (mains) water comes from mountain loch so starts at a very low temperature, far too low for legionella to survive. and having been through the treatment plant, including microfilters, no bacteria could pass though. So being a sealed system with a "clean" source there really is no risk.

I am paying about £550 pa for site insurance via Build Store. And I thought that was expensive.

Yes it is one of those situations where, because a few people could not wire a plug safely, it was decided none of us should ever wire a plug again. So it is a skill not taught any more, so you can pretty much guarantee that a much higher percentage of self wired plugs now are done badly. As I say, this is the sort of "progress" I despise.

Ah the art of wiring a plug top. Someting I learned at about the age of 8. A "skill" not taught to today's children because everything comes with a plug on, and you don't "need" to do it. Progress.

No sorry I don't like that. NO access to any of the terminals to perform any testing, so when something stops working, almost impossible to tell where the fault is. Stick with traditional terminals or wago's and do all you can to avoid inaccessible junctions. I prefer wiring lighting circuits "loop at switch" so all the junctions are accessible at a nice working height. You can use wago's or screw terminals in the back of a switch box.

I strongly suspect that cable is too small for it's length for any significant load. Most DIIYers that install that sort of thing don't understand voltage drop, earth loop impedance and disconnection times. And I bet it has not been tested in any way.

It is certainly against wiring regs, typical of a DIY bodge, Marginally better than burying it 2" under the lawn, at least you can see it. Where is it?

When Scotland made the general move from 100mm frames to 140mm frames, I saw several like that (though without the half block) where the foundations had been done for a 100mm frame and then a 140mm frame arrived and it overhung the blockwork on the inside. Now they use 140mm blocks for the inner leaf.

I have an inward opening door on the expose west end of our house. When the wind is blowing a hoolie and the rain is lashing on the door, a small amount of water gets in around the seal. I wish THAT door had been outward opening. I would not want an inward opening window for that reason alone. I don't see why the direction of opening should affect things like blinds.

I take it you have looked in the obvious place https://www.tspc.co.uk/Search/Plot

It looks like what you need to do is take the roof off and construct something better / larger. I strongly advice against trying to live in the house during such major work. I know someone that tried, and moved out in under a week What you can do depends largely on what planning will allow. For most space a full second storey would be what you want. Is the planners won't allow that consider making it 1 1/2 storey so the upstairs rooms are still partly in the roof. Below are some pictures of our house that use "gable ends" rather than dormers (think of dormers but without the side cheeks) and this gives standing headroom for almost all of the upstairs floor area while still keeping the planners happy (we would not be allowed 2 full storeys here)

Hi and welcome. There's not much you can do to predict foundation costs until you have found a plot. There's not much you can do to even design the house apart from concepts until you know it's size, shape, slope or level, orientation, outlook, location of neighbours, services and so the list goes on.

I suspect building control will not pass this. I know someone that tried it, and they could not get enough tension to satisfy building control that they would not push apart, and so fell foul of the "100mm sphere will not pass through" They ended up putting an additional handrail, which oddly enough seemed to disappear again after the building was signed off. I recall seeing the same issue on a Grand Designs house, there they inserted polycarbonate sheet between the wires, and I suspec that sheet did not stay long either.

Yes that is another vote in favour of an UVC rather than a thermal store, that at least the Telford stainless steel tanks do seem to be pretty well insulated, and if you take care to lag all the connecting pipework it does not seem to leak very much heat into the room. As mentioned the Sun Amp is another candidate. More expensive but very much lower standing heat losses, but a different beast to learn about and how to heat it. I will let the experts discuss that one.