First of all, forget emailing, you won't get anywhere, nobody ever responds to emails that's merely a red rag telling them you're already sending an email to everyone else. See if you can find an individual SE one man band type of outfit rather than a big company. This is a Friday afternoon make...
Well not wanting to play devils advocate here (I've already said it may prove problematic when he comes to sell) but if an SE proves it works (or some version of the OP's utopia) and the modifications are carried out as necessary then the roof won't blow off or fail.
It's pointless speaking to...
Speak to a proactive SE, if you can find one, the brief being that the trusses remain solely for the purposes of creating the roof space and storing not much more than some Xmas decs and a fat plumber fixing the boiler, strictly speaking you do need Building Control Approval and any surveyor...
1p per item x say 1000 items in the car x 1M car sales adds up to a tidy figure, there's your answer.
Exactly the same reason national house builders seemingly skimp pennies on so many things.
Demand to see the engineers drawings then, you paid for them, do they even exist? Maybe all your friends don't have a clue about what steels should bear on.
Fence post concrete should be set in undisturbed earth to get a good bond/create a good foundation not up against loosely filled in backfill. I don't understand why you're doing this.
Because to use the proper building grade types of foil insulations which, for them to work as intended they require an air cavity each side which by the time you add up the overall space required and additional battens to create the gaps it negates any potential space or cost savings over...
Because he doesn't want to rest the roof joists on top of the head beam. He wants the head beam and joists all to be the same height. I'd have just made the bifold head a bit lower, keep it simple Simon!
I would hazard your SE could specify some stubby beams welded to the head beam to create the overhang, then the beam could be restrained on the other side with some straps onto each joist on the other side of the head beam, to stop it wanting to turn over, if that makes sense? Just my first...
Why does the plate stick out flush with the outer skin, it doesn't need to, it could have been set back 20mm or so and still work just fine and the bricks cut to suit if necessary, poor quality design and execution, could easily have been avoided.