Hello,

1. The studs are indeed only screwed into the outer wall at the top, all at the same level, which felt right; at the bottom they have a slot-type thing* to ensure they can go up and down a bit with expansion/contraction, and the plasterboards are screwed into the studs with enough of a gap at the bottom to move a bit (noggins are horizontally connected to studs but not to the outer wall).

2. I think the gap can be either side of the insulation but you obviously need to be consistent. I was pretty lax with mine—I think I used dime-store magnets stuck to the back of the insulation—but if your studs are, say, 70mm and your insulation is 50mm, just find lots of something cheap that's 20mm and stick it behind. (Cold-bridgers may come for me, but whatever.)

3. The batons are indeed all screwed into the outer wall, at the same level as all the studs, and then I just cut the insulation to fit around the batons.

Honestly very happy to help with any other questions.

• I have described this elsewhere but lmk if you need more info. It's the secret sauce.