JohnMo

Mr Punter, seems to make the best suggestion. Combi boiler £1500 is less installed. An ASHP, will need an ASHP, £2-3000, plus larger radiators (to cope with lower circulation temperature), maybe new piping depending pipe sizes you currently have, you easily eat into £5-7000. This leaves several grand to improve insulation and drafts. Giving you low ongoing bills for heating. Get a low energy house first. ASHP good for well insulated and airtight buildings, they need a cylinder to work for DHW. Really wouldn't want to suggest something not fit for purpose, especially as you don't want a cylinder. A good combi, good showers, a good electric shower, worse than a rubbish combi. Both cost the same to run.

Bleed them

The UFH pump would normally come with a temperature control valve, the different temperatures would be set at the manifold. You just run the system at the highest temperature of two systems. Some things to discuss with your plumber. Although your boiler has a good modulation range, will it short cycle, when several circuits have met their demand (no flow required) and the weather is say 10 to 12 degs. Your demand for heat will be very low. Do you need or have you already got a buffer tank. If you are well insulated, it may not be worth installing weather compensation, we have it, but ended up turning it off, as it started to cause temperature under and over swings. Instead we ended up setting a temp that gave the least over swing by trail and error.

How many people installing, one person can do the narrow stuff, but two is better. The wide stuff, is just wide and more difficult, I went for narrow, because it was more manageable.

Carpet very rarely goes under the skirtings, never seen it. The grippers go around the room, normal a gap between gripper and skirtings. Underlay goes inside grippers to fill room. Carpet is stretched on to the grippers Carpet cut and rolled into gap between gripper and skirtings. Either, no gripper, not stretched correctly, or cut under size. We have twist pile and the edges are tucked under.

Not sure of the regulations in Scotland for internal wood cladding, but the wall and ceiling cladding isn't protecting another room space above or to the side, as the whole house is open plan. But as it's mostly all painted, it could have a fire rating. So my guess stays at wood

Have to say not that impressed, all new wood, use of Durisol for instance would have used recycled pallets that would have otherwise gone to land fill or been incinerated, keeping carbon in the supply chain. That with low carbon cement etc, would of actual got some proper conversation, instead it's a Roberson kit house.

Timber. Do they need to make the wood fireproof, oopen plan one bed house, with mezzanine. Found this on another site The COP26 House is an important milestone in the move towards mainstream use of home-grown timber in the housebuilding sector. This will reduce transport miles and carbon emissions while supporting local sawmillers and growers. The COP26 House is a one-bedroom unit with mezzanine studio, with an internal floor area of 70m2. The estimated guide price to build a home like this is between £1,800 per square metre for self-build and up to £2,500 per square metre, dependent on size, location, builder, and final finish specification

What he said

Why bother fighting, get a battery alarm that talks to the others, job done. As TonyT says, photo, update cert, done Peanuts in the scheme of things, why have the added stress.

Daughter stays in a new development house, with mvhr, but I think the whole development, of several hundred houses, only a few have mvhr, the rest are dMEV, so all most likely declared as ProDave says as 3.1.

We told we had to have a second test once house was completed. Anything other than that was not acceptable and a certificate would not be issued - cannot get a final SAP EPC either until I have said certificate. Cannot get a building completion certificate until I have as built EPC certificate.

The tape you referenced is great for sticking polythene and super sticky with that, not what you are looking for the decking, will not stick very well to wood especially if damp.

All my suppliers have charged vat, unless it was supply and install contract basis.

Some other things to consider Above windows and doors you need a drain slot so if water does get behind the cladding it can drain out. Keeping insects etc out, stainless or plastic mesh at bottom of cladding and at any drainage slots above windows and doors. Page 52 on the below download link has Some details. https://www.gov.scot/publications/timber-cladding-scotland/documents/

A cheaper alternative http://www.cpssolar.net/epages/62063063.mobile/en_GB/?ObjectPath=/Shops/62063063/Products/dcie48v1000u1

You can get immersion designed to plug straight into PV, they have to be DC and not that cheap, was thinking if this myself at the start of my build. Just an isolator and DC cables required https://www.zerohomebills.com/product/mypv-dc-elwa-solar-pv-water-heater/

Ours is a Heta Scan-line 8, with soap stone to slow down the heat output.

If your well insulated get one with a small a kW as possible, otherwise you melt. Our room is 6 X 6 and vaulted ceiling 6m high, half a load on min setting will have us opening the windows to cool down after about 10mins

I hadn't though about the compressor running costs, so watching with interest

The manifold doesn't care which side the pump is on, the pump thermostatic valve kit is designed to either side also.

Trouble with a lot of this technology, is moves on too fast. Almost as soon as it's installed it's obsolete or been superseded by something with better functionality or faster. Was going down this route, but the system I was intending to install, became obsolete from investigation a couple of years ago, to point of purchase. So left everything manual instead.

I was meaning the 30mm you mentioned

The insulation should be installed gap free, heat will just bypass the insulation, effectively taking the easy route. Two options remove and replace with better fitting pieces. Or foam fill the gaps to full depth, cut back flush once hardened. What ever is done all joints should be taped with aluminium tape. Is insulation going above or below, to mitigate repeat bringing through the wood?

I have a combi and had three showers running tonight at the same time. Not using this system, but something similar done in a different way. Some food for thought. Combi-SuperFlow-White-Paper-v1-2-4.pdf Canetis-SuperFlow-Product-Sheet-WE-050318.pdf