Mr Punter

Your architect can supply a full set of drawings and spec and submit to building control to comply with regs. This is a fair chunk of work and involves a lot of toing and froing. Once you have your full plans submission accepted it is normal that your builder deals with building control. Try not to change your mind later in the process as it may lead to extra cost. If you fall out with the architect you can appoint a replacement. They won't need to start from scratch but it may cost a bit more.

A load of nonsense that has been introduced. I had these done on some flats. It is mostly a paper exercise, but the firm were doing airtightness testing so this bumped up their money for the half day to £600 plus VAT. Your MVHR will need proper commissioning but you can DIY this with an anemometer.

I don't think it is a good alternative. Caulk is a cheap acrylic filler that is easy to apply and smooth before painting, especially when moistened. You can wipe it off with a damp cloth. It cannot be left exposed as it will look poor. It cannot be used in wet areas or outside. I hate caulk around electrical switches and sockets. Just awful. EBT+ is a polyurethane based adhesive / gap filler that can be used outside. It is more difficult to finish. It is very sticky and difficult to remove.

Should be fine with a string line especially as they know it is important to you.

The job looks very good. I can't imagine it being an issue when you sell. If you did apply for Building Regs you will need to pay a fee and may be obliged to upgrade the thermal insulation plus further fees for a structural engineer. The insurance indemnity is cheap and satisfies mortgage lenders (although there is probably 0 chance of successfully claiming).

Yes I think the chimney effect is much reduced if there are gaps between the boards.

He may be using a petrol disc cutter with a hose attached. Quick and no dust.

Tilt fillet or batten on edge for the eaves course which may need cutting. The epdm will obvs tuck under the roof felt. I don't know how you will fix the slates above. Will you strip them and reinstate inc ridge tiles? The slates look good.

As others have mentioned it may be far better to start afresh. You have not posted an existing floor plan but I guess the works would be very extensive. The "roof lift" may involve a temporary roof scaffold, removing the entire roof, building up the walls and fitting a new roof structure and covering. There will not be any prospects of you living there while the work is going on. If you go down the new build route, demolition costs are fairly reasonable and there are several lenders who will help finance this. You will also be able to reclaim the VAT. It will probably a lot quicker. There will be more cost certainty.

Where is the water from the pitched part meant to go? Is there a gutter / flashing or will it just run over the flat roof?

I agree. I have fairly recently had to pay out about £26k for leaky windows installed by an approved contractor. I am still considering going after them for the money but it may cost a lot to prove.

I think there is a lot of value in measuring, specifying, scheduling, unloading, distribution at site, protection, installation and warranty / snagging. Perhaps an extra 50% on the basic delivered to site window order value.

If it is disused, could you cap it either side of your property?

I have seen it advertised. I imagine expensive, but it apparently at least equals double glazed but only 6mm thick. Get a few quotes / samples and let us know how you get on.

Maybe say what system and manufacturer.

What is LBC? Listed building consent? Have you looked at the vacuum insulated glass?

Labour only?

It would be good if you could update this thread when you hear back from LR / mortgage firms.

One for your SE I think.

These are better for flat surfaces like floors or tarmac. No good in a trench.

It is tricky doing any groundwork near clay pipes. I would replace with plastic. Regarding the concrete you will need to cut it back before it cures, so this evening or early tomorrow.

Would it help if you referenced each of the photos, date, time, adding plot number, lat, long and altitude from the iphone data, and note (like "cavity closer") so it presents the same information as the app? I cannot see how slightly inaccurate geolocation entirely invalidates the evidence you have.

If the brickwork is getting saturated you could treat it externally with a coat of StormDry.

There are mixed views on multi foil insulation. Given the choice, I would go with fibreglass. Some of the multi foils are highly flammable.

Just pour some water on the top. It stops the air getting to it and prevents it curing. It will last 3 months. I doesn't mix with the water. I have just used Joint It Simple but there are lots of brands.