Mr Punter

https://www.jameshardie.co.uk/product/accessories-and-tools-cladding/ the ventilation stuff

I have used the perforated metal stuff from James Hardie. They do a bottom profile which gives a kick to the first row of cladding or slate and a l shaped top profile.

We have sliding door wardrobes and the end doors have soft close which fits to the top of the door. I can see that @nod is a dab hand with the metal stud!

Petrol masonry saw?

I think @Dreadnaught is about right with his thoughts. The main things affecting £/m2 sale prices and desirability are 1. Location 2. Kerb appeal You cannot do anything about the location if you already have the plot but the front elevation is what people will see on Rightmove so make sure it looks right. For the space you have downstairs: open plan kitchen living dining (with divider if pos), downstairs WC / utility (a utility with a WC), study / desk area. upstairs: 3 beds, 1 bathroom (bath with shower screen), en suite shower (large shower). Wall space for storage in each room. Plan the layout very carefully so you don't have wasted space. Floor coverings: Hard flooring downstairs - same throughout looks sleek. Carpets to stairs and bedrooms. Luxury vinyl tile to bathrooms. Gas CH. Don't bother with UFCH unless you have tiled ground floor. Combi boiler. No home automation.

Pedestrian or vehicle?

Once you have stripped back to the membrane I think you will probably not get too much water ingress. Then get it PROPERLY designed and detailed - including detail sections through each junction. Then post the design here for comment. Then build it to the design.

Well played! It is only a row of chipboard boxes.

I don't know of any you can drive on. I have used some plastic pedestals but they are only for pedestrian traffic. I imagine you would need a fairly hefty galv steel support system to drive over and would be £££

I suggest a liquid product so that you can easily detail around and onto the upstands.

Good luck! I saw a firm called Plykea who do ply and Formica doors, plinths and panels for Ikea Metod units. You just send them plans and they work out what you need.

Off topic but a nice job on the paving. What make is it?

A BBA approved render carrier board (such as Bluclad) fixed to vertical timber battens. You do not need an approved installer. You can then choose the render and colour at your leisure.

I have never seen these before so googled https://www.strongtie.co.uk/products/detail/slotted-z-clip/79 They are for noggins. I was expecting truss clips. Ask the designer if you need anything else (holding down straps etc).

BTW is the steel still structural or was it just temporary? It looks badly corroded.

If you have membrane on the ceiling it will need to have a fall to the walls or water will just collect and pond up there. You could just pitch a tent!

I have heard it called Mum and Dad but only blockwork.

The house looks very handsome. Compared to the flint work the rest of the job will feel easy - unless you plan on making your own clay tiles.

I think the concerns are valid. Unlike traditional formwork, with ICF you are not able to inspect the concrete as the shuttering is never removed. Why not get this priced in steel with concrete for the basement? What is the preference of the SE? I have done a basement in ICF and we used a type C waterproofing system (internal drained cavity membrane) with a pump. No complaints from the owners.

Even as is this would be a dream house for most people. Are you going to demolish entirely including foundations, or modify what is there?

OK well hopefully you have now established the cause. Before you put it all together again, can you get someone to do a proper design and spec for you to follow as winging it has not worked so far.

Hi Tim You have never self built before but have posted twice on the leading self build website promoting the same company, who I can only assume you have never used. It looks like spam and smells like spam.

Perhaps take up the paving just around the rooflight to expose the membrane.

Josef Fritzl

Very odd that consent was granted with the tree in place. Did anyone produce an arboricultural report? I think the tree has to go.