Roundtuit

If you haven't already, spend some time on the websites of mvhr suppliers (eg BPC) and see what kit is commercially easily available; there's a lot of useful info out there. Ducting comes in standard sizes, so you only need to establish whether you need 1 run or 2 to each vent.

Yes. I'd definitely do it to stop moisture getting trapped. I thought 8mm looked too much, so compromised with 5mm.

To be honest, I don't think there's any point worrying about it now. Sounds like a few months isn't going to make a difference to the condition; I'd wait until the roof is sorted.

Top pic is a nice roof with bonnet hip tiles. Bottom pic is concrete tiles; a cheaper replacement perhaps. Why do you need a new roof? Looks in reasonable order from the outside.

You need a level threshold and disabled access at one door, but it doesn't have to be this one. I can't see BC objecting to your plan; it's effectively a big doorstep, under cover.

I'm sure you can estimate ACH based on an airtightness strategy, but what you actually end up with depends on how well the strategy is implemented. It's all about attention to detail, and most trades struggle to get their heads round it. If you're on site every day and able to check every penetration and interface in your airtightness layer, spec good doors and windows and don't even consider open fire places/letter boxes/cat flaps, you'll be fine.

We've got a 'room sealed' wood burner for supplementary heating. The air supply is ducted in under the floor insulation. Cold bridge? In theory, yes, when it's not lit, there will be cold air passing through it, but nothing that is noticeable. Stuffy air? Nope. Mvhr does its thing, stove sucks what it needs from outdoors.

Our recommendation, which we followed, was roof on first (or at least loaded-out) to 'settle' the frame, then brickwork, then windows. The windows are set about 40mm back from the face of the brickwork and span the cavity and are fitted using compriband.

How about this: https://www.ebay.co.uk/itm/111957681280

I got some led flood lights from screwfix on offer, twin lights on a tripod. Can't recall the price, but I thought they were really good.

It does look great, and I can understand the reluctance to take it up. Now crack on and get it raised, anything else is not really going to be a satisfactory solution I fear.

That would require a route for the air to get in to the house too; ie open your downstairs windows & doors. Not much help over night, or with mvhr.

I'd just use decorators caulk as its paintable. Not sure taping would have been standard practice when they were installed, and there will be quite a bit of making good if you take the window board out I reckon.

I lined ours with some strips of 6mm ply before boarding to close the gap and get over the fixing brackets. You could double-board, depending on how much you need to make up.

Your proposed kitchen area downlight arrangement is similar to ours, and I'm happy with ours: all bulb fittings, so you can change the colour temperature to suit, and two separate circuits (cool white over the 'business area' and daylight white over the eating area), both dimmable to suit the mood. Also led strips under the island which provide a surprising amount of 'background' light. I know I'm at odds with the prevailing view, but I really don't like yellowy lighting; I think it reminds me of the nicotine-stained 70's.

Not the external thermostat?

I'm going back probably 10 yrs, but I think a vertical sash unit approx 900mm x 1400mm was around £300 at the time. We used https://clearviewsg.co.uk I have no connection, other than using them, but they were great for advice on spec and measuring up etc. I see they have an online price calculator so that might be worth a try.

We used secondary glazing with standard glazing in our bedroom on a listed building facing a busy road. We probably had a 150mm gap, and the difference was amazing; I wished I'd done it 3 years earlier. Sealing any gaps around the frame is key.

F me! You're good! Can you do Liz next pls?

Core temperature above 70C for at least 2 minutes. We all know the problems with undercooked bats...🙂

Looks like an evaporator with a few bent fins. Seen worse tbh, but not much 😆

Expanding foam, trim level and tape over with your tape of choice?

Maybe if it's limestone. Granite should be OK.

As above; go and have a look around your local garden centre or somewhere that sells sheds etc. Get a feel for how they fit together, take a few pics for reference and give it a go!

Have a look on Google earth; there might be some clues about what was or wasn't there historically.