ProDave

If you have good dry lining boxes like appleby that clip securely in place and stay there, okay to fir the boxes before skimming. If you have chosen lousy boxed that barely clip into place, then no, don't think of fitting them before skimming.

Plasterboard boxes come in different types and different makes. Some are dire and likely to give problem. I always use Appleby, sold by Screwfix and Toolstation and they are the best I have found. If you really want, you can get (from TLC direct) plasterboard fixing metal back boxes. I prefer to go and cut the back box holes before the plasterer goes to skim, at least I know all cables are present and connect and the boarder has not "lost" any of them. If you really really really hate plasterboard boxes, you will need your joiner to fit dwangs (noggins) at the correct depth to fix ordinary boxes to.

Well make him un change it then?

Were they cut before or after plastering? After definitely wants a multitool, NOT a saw.

The lesson from this is check it is square BEFORE the plasterer comes.

Is it essential they rotate? That looks to be the tricky bit, needing a slip ring arrangement for the power.

You can't appeal without a refusal. Has your planner given reasons why it might be refused? Can you alter anything to satisfy them an re submit? If you make changes now and re submit, you will be in a better position if it does go to appeal as you can show you tried to adapt the scheme.

So your solar PV is charging the battery instead?

I did one of ours horizontally, but a completely different situation: In this case the wall ends low due to being room in roof, and there was less than 1200mm between the top of the basin and where the wall becomes sloping ceiling. So putting it on it's side avoided a vertical joint, and there are 2 invisible horizontal joints either side of the vanity unit.

The issue might be getting the airflow low enough, iirc it's a fixed fan operating from the oil pump motor and the airflow is adjusted with baffles. You might run out of adjustment? Perhaps the smaller burner has a smaller fan? but if the boiler at our last rental property was anything to go on, it was old and tired and he could only just get the airflow high enough.

You should be able to de rate it by changing the burner jet but you will need an OFTEC plumber with a flue gas analyser as the burner will need to be set up from scratch with new air settings etc to get the combustion right.

Our "as designed" SAP was I think 89B I thought that was poor and worse than I hoped for. BUT they got the roof insulation detail wrong (the roof is better insulated than they calculated) and they based the SAP on 4.5 ACH I hope the as built SAP will be better.

So draw a pan of water from your boiling water tap then.

Hotter than I can stand. Although I can stand putting my hands in 48 degree water for washing up. that is too hot for most of my body. The fact I can, if I wish get the shower water too hot for comfort suggests it works with a lot less headroom than the manufacturers suggest.

I run ours at 48C hot water temperature and the shower mixer copes with that okay. You would not want all your hot water less hot than that would you? I arrived at 48 degrees as that is as hot as I can hold my hands in without it hurting. You want hot water for washing up, so anything less than 48 degrees and I don't think the washing up water would be hot enough. Also if you stored the hot water at say 38 degrees, you would not be diluting with cold for a shower so you would need a larger capacity hot water cylinder.

How do you find a thermal store works with an ASHP? I thought the conventional wisdom was because you have to store the water hotter in a thermal store, they are a poor match to an ASHP that will struggle to get them hot enough?

Mine was one of the Kingspan badged Misubishi Lossnay units that was sold on ebay a few years ago when I think Kingspan abandoned that market. I only paid about £400 for it. I would have to look up what capacity it is. I have two 75mm ducts to each terminal and at normal speed it is inaudible. At boost speed, used when showering, it is a bit noisy and I would not want to have to run it at anything like that speed all the time. It performs very well, the air in the house is always fresh and heating bills are low so the heat recovery must be working.

I don't trust that data. Using that map, and the figure for South Oxfordshire OX10, it suggests my 150 square metre detached house would be worth £513K if I picked it up and moved it there. There is no way you could buy the house we have up here, in south Oxfordshire for £513K. The cheapest area I could find was £890 per square metre. So it would be "worth" £133K That is less than the build cost, so even if you were given a plot for free it would cost you more to build it than it was then worth.

I (and a few others) have a Lossnay MVHR unit operating on it's own. My concern would be to move a useful amount of heat, you would probably have to have the airflow at a higher rate. I run ours at the minimum rate most of the time for silent operation, a higher flow to shift enough heat might make it audible.

More paperwork. I can understand a developer being asked to provide that, but you would think common sense might prevail and a self builder who knows the house inside out and is living in it already so obviously knows how to work it, would be exempt.

But what is the point of designing what the architect wants if it is so far off what the client wants. It should be a 2 way interactive process perhaps with a day spent together drawing sketches and agreeing a compromise between what the client wants and what the architect thinks is possible, then go and detail it to that agreed compromise. To just design something completely different without even discussing it is just wrong. This has nothing to do with 7 years training, it is just bad business practice. I am an electrician, I try to fit what the customer wants, if there is something about what the customer wants that makes it particularly difficult I will discuss alternatives with them and agree between us what I am going to do. It would be equally wrong of me to put all the lights and light switches in a different place without discussion because that is what I feel is best.

Also fit your skirting AFTER tiling. this gives you room to be a bit less accurate with cuts as the end gets hidden under the skirting. As @Temp says you do NOT want to end up with just a thin sliver of a cut, so if that is going to happen, start at a wall with a half tile rather than a full tile to move it all over by half a tile.

In the extension you will still have 1 oven and 1 hob and 1 washing machine etc. Heating load will increase and hot water load might increase if you have more people in the house, but I think in your case those are not electric. So no I would not worry, I would stay at 60A which is 14kW plenty to run all your stuff.

For my hall and utility that had 4 different sized tiles and laid to a repeating pattern, I did a scale drawing of it on the computer, then jiggled it around to best fit. I put it so all the cuts were under the utility units and thus hidden with full tiles meeting the other wall. The en-suite and bathroom were completely different. Both wet rooms, so for those start at the shower tray with the cuts to form the slope down to the drain, and everything works off that, and you will get cuts at all the other edges. Don't cut the cuts until you have laid all the whole tiles and got to the edges. Lay whole tiles one day, cut and lay cuts next day after main area is set.

The ASHP is like a system boiler. It runs on a sealed system that you charge with a filling loop and 2 bar is more than enough for that. You can have a vented cylinder if you really wanted to and a header tank, but in a bungalow the pressure from the header tank would be poor. A better solution would be an unvented cylinder with an accumulator to boos the peak flow rate.