torre

You might want to ask the builders merchants for a price on the Keylite equivalent, probably quite a bit cheaper and still good quality.

With something similar using masonry our SE specified expamet fixed to the top of the horizontal steel and wall starter ties fixed into the sides of the vertical (we used self tapping screws) Maybe it's just unclear from the photo but is your steel at the far end sat on blockwork rather than a padstone!?

With the caveat that everyone's 'acceptable' varies, I've done similar in the past by clamping the tail in a workmate, so the whole edge is held securely against something with a small radius, then using a sheet of ply to apply an even force to the rest of the aluminium, ideally limiting how far the bottom of that ply can move away from the aluminium. Main thing is to be clamping the smaller side and working the larger side. I agree this is no substitute for paying for fabrication of course and you need to be sure you're not going to do more expensive damage than you might be saving

Plastic lintel soffit cladding might be another option, it'll cost more but need less maintenance (probably easier to install before the windows though, sorry)

I'd echo what @ProDave said about PPE. Definitely a full face respirator mask. We did a similar job but from above when replacing floorboards and used Thermafleece (wool) which is way nicer to handle but pricey and hard to cut. Of the rockwools Knauf products like Frametherm do seem the nicest to handle and shed less fibres. Instead of netting, use a breather membrane (and tape it to the wall edges all round, you may need to PVA walls before taping) as that will cut down hugely on draughts. The whole job will be difficult and time consuming but the results are transformative for comfort. Are you sure you have access to all the crawlspace? Our joists were supported at half span by a low wall.

Scaffold debris netting is really cheap and it's easy to fix multiple layers over your Heras to trade off letting wind through versus total privacy. If you want more wind protection then diagonally brace using a scaffold pole fixed to the Heras with a swivel coupler onto another pole fixed into the ground.

This is definitely not permitted development, not just for the reasons you've mentioned but because you're changing a relatively low profile hipped roof at the rear into a much more prominent gable end. What's at the bottom of your garden? If there's no neighbour then you probably stand a good chance of getting planning permission but if there is then you may need to compromise a fair bit (lose the gable end or at least the window in it for example.

Agree your shadow gap isn't going to happen except at great cost - you've already got a taste of the effort. What's going on with your hinge plates showing? That door is closed isn't it, is it just something temporary?

Do you mean safety once installed rather than handling? Taking Velfac as an example (as we'll be having them) They bridge the cavity below the window with 3mm or 5mm steel plates at the load points and the fixings are into the centre of inner leaf block work. Not ideal from a bridging perspective but at those weights hard to avoid

Not a professional tiler but an amateur who would be unhappy if my own tiling looked like that, even though the lighting is probably amplifying faults a bit. Bad tiling, but do you have a few leftover tiles so you can prove to your original tiler that the tiles themselves are pretty flat? Plus ideally a picture of the wall before it was tiled onto. If you pointed out the lippage was that to your original tiler or the guy on site? They had the chance to get the tiles and adhesive off before it was fully set and it's a shame they didn't take it. I'd suggest to the original tiler that they need to come off - that you'll bear the cost of replacement tiles as needed but they need to redo the work at no extra charge. Hopefully you've not paid him and he's not paid the guy he subbed out the job to.

Yes exactly

Biggest difference I see is the magic elves (well, the big fan anyway) tirelessly directing their sealant into the worst leaks in any hard to reach spaces you've missed and can't easaily get back to. I hope not to need the product but I'll probably have a pre-plasterboard blower test and then assess. If I'd known this I might have gone straight to them and saved doing a parge coat!

If building under permitted development you'll still need to apply for tree works permission if protected trees may be affected

Obviously there's positive internal pressure when installing the magic gunk, but do they do any final test with negative pressure? Would love to see pics, for larger holes I can see the stuff will gradually build up, but it's not clear to me that the seal would necessarily be as effective when the pressure is reversed. I assume they charge more according to how long and how much they blow, so sensible airtight measures are still worthwhile first

I agree, but if you thought 19 objections last time was a lot, this will probably stir up more and open up other possible grounds for refusal (not in keeping with the area)