Mr Punter

Well the good news is they haven't tried to cover it up. Get a full survey and report. Make sure it includes roof condition, timber condition, damp, dry rot and condition of brickwork.

So is this an insulated masonry cavity wall?

You need to confirm with the contractor that they will immediately spray the curing compound on the finished slab. If the water evaporates from the slab too quickly the concrete will not properly cure. That said, the house will not fall down.

If there is only 1 layer you will be fine with the overlaps. If you can get someone to help placement it would help a lot as the sheets are heavy and awkward. You may want some tie wire where the sheets join and allow for a 300-400mm overlap (40x wire size).

On a gable with a raking roof abutment and windows, it is hardly glory work!

Stapling the tape on may help straighten it up a bit. Get it clad ASAP.

Looks fine. I would normally expect to see vertical stapled on tape to identify where the studs are.

Keep the higher bits as close to the surface as possible, especially of it is path only. 300mm min cover is fine and you could do less at a pinch. Use the mini shallow ICs at the sides and back and for corners where you will add a 45 either end. Avoid clashes with the surface water system. Make sure the foundation is low enough where the pipes cross at the front. This can just be short sections.

If you are that tight on fall, could you raise the building by 200mm? Hardly noticeable I would think.

I don't know why you redesigned this. Are you short on fall? You have about the same number of ICs as the original. Not sure why the line at the front has moved 6 metres. It may prove another obstruction. Very large property! Can you feed the drawing to an AI chat?

I must say that if it means application details are easier to complete to LA satisfaction then the AI approach sounds like a win all round.

You could fully fill with 140mm pir between studs and line internally with 50mm pir, held on with 38 x 50 battens to create a service cavity. You could put the 50mm on the outside but you will need different wall ties and another layer of breather membrane etc. You will need about 30mm cavity to the brickwork. If the timber frame co quote for the insulation it saves a lot off faff and mess on site.

Insulation tends to be mineral wool or PIR. What is the proposed "rain screen"?

This type of unit MUST be installed and commissioned by a legally certified F-gas installer.

And while you are doing this you could look at modifying or replacing the first floor cills. It is difficult to chase out cement mortar from soft bricks without damage. Do some research on what you want.