Mr Punter

If you have room on the foundation, brickwork or rendered blockwork can be cheaper than cladding and should meet all your priorities.

A small amount of water ingress where you have a high water table is standard. Some of the plastic chambers have rubber seals that can be fitted between the risers, but they can be pain to fit. Regarding heights, it may have been best to have proper drawings based on a topo survey, with heights and inverts marked, but you would probably be up for an extra £1.5k in fees. Since the IC is between the back of the garage and a hedge I don't think it will matter. Also, better higher, so it does not become buried in the undergrowth should you need to access it. It may be worth you suspending work and employing a surveyor or site agent to do a fortnightly check in a Clerk of Works type role.

The weight of the frame is mostly resting on the 200mm polystyrene. You could extend this or move is outward by 74mm and finish with the same ali sheet you propose elsewhere.

I can't work out what the materials are. What are they where you don't have a door?

From tales of your previous tenants it could be wee...

If the breaker is 32amp you can use your new dual appliance outlet. The induction will draw max 15 amp and I guess the oven is likewise. They will only very rarely both be going full tilt.

Could it be condensation? If the room is occupied it could be generating a fair bit of moisture. Would a dehumidifier help?

Is the damp evident on the dining room side?

This does not sound like a formal refusal. They normally quote which policies it would be contrary to. You could appeal.

When the wall is dry you could apply a coat of StormDry. It should last 25 years and keep the wall dry while still allowing evaporation.

The timber frame will shrink as it dries, moving downward compared to the stone, especially on upper floors. The detail needs to accommodate this differential movement. Compriband sealing tape is often preferred over mastic as it offers more flexibility.

Maybe have a good count up of your fingers this evening, just to be sure!

You could cut the top and add a newel turn - have a look at Richard Burbidge.

Gosh that is expensive. Could you do it in slate and / or lead? The gutters in aluminium perhaps?

Did you use the grinder shield onto the skirting top as a guide? Was it cordless? I am not sure I would be happy with a grinder in one hand and a vacuum in the other!

If you clip the cable to the stud it will help, as timber is not as insulative as insulation. I think this is only an issue if you have high loadings through the cables. In the past we had to use 4mm cable for power circuits but it seemed really OTT. Your sparky is the one responsible for this call.

I think you will suffer from overheating via unwanted solar gain especially in the breakfast room in the afternoon / evening. I doubt the dining room will be used for dining. Sliding doors give more opportunity for controlled ventilation than folding. If the system allows you may have the option in the family and kitchen to friction brake the doors in whatever position you like, but the 2 leaves in the breakfast room will just flap around in the wind.

Why not chase in a bit higher so a wall chaser would work? You could move the sockets up a bit. Sockets down to the skirting is old school and you have to grovel around to plug anything in. If they are all in line I think it is fine for the regs.

Get on to the manufacturer and see what they have to say.

It can work well to create a service void in the walls with vertical battens, so you can route cables and smaller pipes. You can also run these in the ceilings or create a service void there too. Network cables are very simple to run. More difficult services are soil pipes and ventilation ducting.

I don't think it will make much difference either way. The condensation point is nowhere near the joists. The aluminium on the insulation will help reduce vapour.

I don't think there will be any issue.

To put your mind at rest you could do a condensation risk analysis. I don't think you will have any issues as there are 2 layers of foil backed insulation, so as long as they are snug round the edges you should be fine.

In spite of the name, Porotherm has not thermal insulating properties. Quite the reverse, as it has hallow voids that allow air to move inside the blocks. Also a pig to fix to as they shatter. No fun to cut either. Sockets, pipes, wires all a pita. Also you will struggle to find anyone willing to install and may have issues with wall ties and brick coursing. Why is it on the top of your list?

Simple to remove the wall profile. You will need a Stanley knife to cut the mastic.