ProDave

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.

If you want minimum price per square metre (and wile we are at it, minimum heat loss per square metre) that design is NOT it. On such a large site, I cannot imagine it is the site making you build to that inefficient shape. If you wanted cheaper build cost, I am surprised your ex architect did not mention this to you? P.S we only tried to have dealings with an architect once and his estimated build cost was twice what it finally cost us, for almost the same house.

YES. I have a pretty standard 4kW panels and 3.68kW inverter, but when I submitted my paperwork (pre G98, I forget which) I got an almost instant reply to disconnect it immediately and apply for approval (what would have now been G99) And telling me there would be a fee for even applying. In my case they had seen the inverter model number which contained "4000" and assumed it was a 4kW inverter not 3.68kW and were demanding prior approval, even though that would only have been slightly over 3.68kW. Sending them the paperwork for the inverter confirming it's output was limited to 3.68kW sorted the issue, but it showed there is no leeway. To date in over 3 years I have only exported just over 300kWh. the fact you don't intend to export is irrelevant, the fact is you could.

Yes interesting project. It would make a change for such a building to be something other than a very cold impossible to heat stone building. Net zero is easy. Any house with enough roof space could fit enough PV to generate in a year more than the building uses. It would NOT mean zero bills or off grid because most generation would be in the summer so you would be exporting and most usage would be in winter and you would be importing.

A self builder near me had this discussion with BC and won. It boiled down to the distance to combustibles thing. A stove where they guarantee no more than 100 degrees at the base still needs 12mm to combustibles Presumably to cater for hot ash falling out when refueling?. It does not need a constructional hearth. The self builder argued it was 10mm tiles then 6mm tile adhesive then a floor screed so the combustible issue did not arise. BC failed to find any reason such as a step so passed it. In out last house we had a constructional hearth and tiled finish and wooden floor in the rest of the room and I deliberately set the tiles level with the wooden floor. Again BC muttered about wanting a step but when asked to show me where is says that, he could not and passed it. The 12mm thing allows you to put a 12mm sheet of glass onto a wooden floor and that will comply. In this house we have a 20mm thick slab of granite on top of wooden flooring.

Is this an electric under floor heating mat? What insulation is under the floor? What is the present heating system?

Every manufacturer of a stove will publish the clearance distances from sides and back to "combustibles" and it will vary from manufacturer to manufacturer. For instance our Medip Stoves Churchill 5 convection model requires only 150mm from side to combustible materials and 100mm from the back to combustible materials. It is 550mm wide so in an opening 900mm wide the sides could be combustible material, i.e. plasterboard. The 5kW thing is irrelevant for you. A stive under 5kW may be able to get away with no combustion air provision and just draw air from the room. You are proposing a room sealed stove with combustion air direct from outside so you can fit any size stove that is appropriate. This is the current version of our stove, changed slightly from the one we bought several years ago https://www.mendipstoves.co.uk/churchill-5-convection-logstore-dual-control-ecodesign-woodburning-stove