ProDave

Why do you not want to sell? You hold the key, it could be worthwhile, enough even to then sell up and move elsewhere? Worst case is a compulsory purchase for a small sum of money.

I took the general consensus that in a near passive house, heating upstairs was not needed. My backup was I installed an electric point in each bedroom for an electric panel heater. I never bought any heaters and the points have not been used. We keep the bedroom door shut to stop too much heat getting in from downstairs. If ever the bedroom gets a bit cool, just open the door and and let some heat up the stairwell into the room.

We like a cool bedroom, which is why no heating at all upstairs works for us. Even at this time of year we occasionally open a window to cool the bedroom a bit.

Trying to work out what feeds what and what keeps tripping. Is the one in the picture with the lid open the one that keeps tripping? If so post a picture of how that connects to the meter and the other CU's please.

The immersion heater is a round thing near the bottom of the tank with a thick cable entering it. It will have a round cover sometimes plastic, sometimes metal, usually secured by a single bolt. You need to remove that cover to see the thermostat for the immersion heater. Post a picture of it here. Any other thermostat with a visible dial and usually higher up the tank is nothing to do with the immersion heater. Why not just call the installer that fitted it back and tell him it is not working since he fitted the new cylinder.

Our north facing windows have almost permanent condensation on the outside at this time of year. Indeed it's ice on the outside of them at the moment. As above it shows they are working and not letting enough heat through to melt that ice.

A picture might help understanding?

Serious suggestion, I would just paint it with a good rough finish masonry paint. I am not a fan of render on walls like that, probably because up here where we get very cold weather in winter, I see no end of rendered garden walls where the render has blown probably due to water soaking in then freezing.

The links to the pictures don't work for me.

Yes sorry to say that is not good. The ends are open to the cold under floor space, and that means the cold air can get between the spreader plates and the insulation. Your insulation will be a lot less effective than it should be because of that and you will waste a lot of heat, lost to the under floor void. We keep on about attention to detail being necessary for good performance, and that is sadly a good example of how performance has been degraded by a basic lack of understanding or just plain can't be bothered.

Lath and plaster has a cavity stud wall behind it. Surface mount switches with the wires in the cavity should be possible. the problem with lath and plaster is it is near impossible to flush mount switches and sockets. But if you are happy with surface boxes it should be possible to hide the wires inside the wall.

There is a BIG difference between a boarded loft and a properly done loft conversion making a habitable room(s) A LOT more details including pictures please.

That is not a "consumer unit" but just an empty box which could be filled with the components to make it a consumer unit.

Are you sure you are not a Barista?

That seems to support my theory that a totally level floor with just a different colour for the hearth is acceptable, as in my previous house that had a tiled hearth and wooden flooring both set level, a clear visual boundary. If you are tiling the whole room and want it level, tile the hearth with different colour tiles.

But the regs do NOT call for a change of level. They call for "visually apparent boundary" so would you accept a totally level tiled floor, but with the hearth bit tiled in different coloured tiles to give that visual boundary?

If you were my BCO I would contest that and ask for another opinion, as nowhere in the regs does it say a change of level is required.

Did you light the stove while he was there and did it work okay now?

1950's uninsulated house, ASHP would not be my first choice and neither would UFH. What was there before?

so it says a way of achieving this is a change of level. Note that is not the only way, it needs to be "visually apparent" so a change from tile to wood is pretty visually apparent, without a change of level. If they really required a change of level it would say there must be a change of level, not that a change of level is one way to make it visually apparent. This is very much open to interpretation, a very poorly written definition.

Oh the joys of not being metered for water.

First fix is installing the cables ready for plastering the walls etc. I certainly would do that in wet. I would not do final fix, connecting it all and testing it until the building is dry.

So you rent the bungalow? there's not a lot you can do to change it is there?

So where is the diagram showing the case where the whole room is non combustible flooring. It only shows there must be a transition from combustible to non combustible but does not show what, if anything, is needed where the whole room is non combustible.

First fix yes, advise him to bring wellies and a raincoat for if the roofers don't get finished.