ProDave

I thought you had just described how a KP gets treated? I have only once had a "set to" with someone on a building site generally I found it okay, but I am an electrician not a joiner, but know lots of joiners and most are good. Who is treating you like that? People further up in the company that employs you or other trades that you just bump into?

When I fixed my pump last week, I did have to poke the contents with a stick to break the crust on the top, just to be able to confirm it was blowing bubbles and nothing was blocked. It was blowing fine. Below the crust it was liquid all the way to the bottom. Awaiting it's 3 yearly pump out just for good measure.

I think the point of @ETC revised layout, is whatever room layouts you have, you want the entrance and stairwell near the middle of the building, not near one end. Then you can access all rooms with a minimum of corridors (wasted space) to get to them. This was a major design requirement of our house.

My bet would be one of the rollers has failed. As above the door needs to come out, not a DIY job.

Mine just failed 2 weeks ago at 7 years old. £36 for a replacement kit and half an hour to fit it.

Yes but so does the Bio Disc type. They have a motor permanently running driving the rotating disk via a gearbox. If anything they are more noisy than an air blower.

We only had ADSL available. so changing supplier would not improve what we had available. Briefly tried Talk Talk. They would not fix a line fault, they just kept sending me a new router, so had to move back to BT, still with the line fault and at least they got OR to fix it. I was waiting for FTTC I would have been happy with that. They could have installed a cabinet at the top of our road and all the houses here could have had FTTC which would have been a vast improvement, fibre already went past the top of the road. But no, they were not interested in such an easy improvement. Star link was not available and mobile signal too weak and too slow. So we were stuck with a monopoly offering a poor service not interested in upgrading to offer something better. When another local wireless (not mobile phone network) supplier extended their network to cover us I was happy so swap to a forward thinking local supplier and now have 100MBPS both ways and customer service you can actually speak to. It would be a sad day if I had to go back to the lousy under invested sub standard offering that was all that anything involving OR could be bothered to offer us.

Mine is in it's own compartment in the top of the unit. It really is a simple job to take the pump out, recondition it and put it back. No need even for gloves. You do not need to get involved in the "contents"

Buy a system scaffold like Kwikstage, Cuplock or I am sure there are a few others which are really a scaffold tower system with infinite possibilities from a single tower to a long run of scaffold. I would not for DIY buy conventional plain tubes and clamps.

My hatred of anything involving BT or OR. The most lousy backwards looking, awkward to deal with inflexible pair I have encountered. If you have an alternative, I would go for it (I did when one became available)

Our stairs are just like that. And we have a nice tall window to look out of. I often think a chair would go nicely there.......

The whole coverage thing with mobile signals is a very complicated subject and one that is hard to get full information on. The new EE mast "near" us is in fact about 3 miles away, would be line of sight if some trees were cut down (a whole forest of them) However not all providers offer the same service. My main phone provided by 1P Mobile used the "full" EE network, and that gets a good signal at home and gives 4G and voice no problem. Network Cell info is a handy app to have on your phone, and this tells me it is getting it's signal on "Band 20" one of the lower 800MHz bands hence it goes further. I also have an "activity phone" Not usually used as a phone but rather as a small tablet it has mostly navigation and walking apps. To enable it to access a bit of data, it has a bargain basement sim with RWG, another provider that "uses the EE network" But, being a bargain basement service it does not offer either WiFi calling, or VoLTE (voice on the 4G network) The result of not using the full EE service is that phone does not operate on band 20 so rarely gets a signal at home, and then it is very weak. So that service would be woefully inadequate as my main phone All that is a long winded way of saying you really don't know what you will get until you try it.

I would have guessed Plockton from the choice of user name.

BT gave us one of those when we had a line fault. It never worked for us. There was so little diagnostic available on the thing I still have no idea if it was lack of signal or it was not enabled or set up properly. At that time I know we got almost no signal from EE which is the network I believe it uses. Only some time later did EE build a new mast closer to us that gives us a better signal, but even that is not brilliant.

If you are getting an adequate speed from the 4G / 5G network, I would not even entertain anything involving BT or OR and just seek out the best deal you can get from any of the mobile providers. But do check the mobile provider with the best deal does cover your address, e.g. three seem to offer the best deals but their signal is non existent here.

A straight stair ending near the back wall of the house is only an issue if like us you have room in roof with restricted eaves height. I thought your plan has full height upstairs so you will have no problem at the top. A compromise might be a quarter landing near the top, 90 degree turn for the last 2 steps?

With one bedroom and 1 bathroom downstairs make it Jack and Jill so it can be directly accessed from the bedroom as an en-suite or from the corridor.

That is an old and very common way of bracing the joists to stop them twisting. More commonly done with solid noggins now. Why not replace with solid noggins with large round holes drilled in them for the mvhr ducts to pass through?

Comfort in use is largely a case of what you are used to. The going of our stairs is a lot more than the minimum. I can get my size 9's flat on the stairs entirely on the stair. Contrast that to many older houses, built before modern building regs where the going of the very short stairs is only about 3/4 the length of my foot. That now seems an insane design to me, but as a younger man used to stairs like that, I thought nothing of it.

Our house is 7M deep so only a bit more than yours and especially if you are having room in roof or 1.5 storey, as you say you may get into head height issues. For this sort of house a stair split into 2 with a half landing works well. In our case up 6 stairs to the half landing, turn 180 degrees and up another 7 stairs and you arrive on the upstairs landing at almost the highest point of the roof structure and no worries whatsoever about head height. I then took the available space we had, constrained by doorways downstairs and upstairs, and made the going as long as it could possibly be and I think we arrived at about 40 degrees. All easy to do with the Stairbox on line tools and that is who supplied ours. The challenge will be to design a two flight stair as a floating stair, I leave that for someone with more imagination than me.

You need to make the place a bit more upmarket. A new mirror will help them see what they are doing. I have found just the one.

Link gives me 502 Bad Gateway.

One more reason not to be a LL.

Get a quote for the electricity supply, then you will know for certain where it actually has to connect to. Then see if once you have accepted the quote they can issue the cable for you to bury in the field. It does not have to be in duct is is usually suitable for direct burying. If you do go for duct, put large diameter twin wall flexible with gentle bends, don't put elbows. Then never contemplate using the provided drawstring, use that just to pull through a larger bit of rope as your drawstring.

When I was building my house, I too did not believe it would require so little heat. So I did a test. Once the building was complete, insulated and all windows in I put a simple electric convector heater on 24/7 in the middle of the downstairs, for a week, and took daily internal and external temperature measurements, and confirmed the difference was in line with what you would expect with that much heat input thus proving Jeremy's spreadsheet was bang on. I then had the confidence to buy a heat pump.