Door/hatch clearances and hinges

[Giblets46]

So an update on this, seems to fit pretty snugly, got a clearance of 15mm across the door, used 20*100 wood for the frame in the end, with a strut halfway.
In terms of the support I got a gas spring that is pretty compact and supports the weight and opens when about 20/30% open, then fitted a couple of grab ropes for handles, to help with opening and closing.

 

[big-all]

yep looks good well done
as an aside cant see what you have done but draught excluder works best on the hinge edge on the door end and frame where it will compress rather than on the stop where the door can "roll it off"

 

[Giblets46]

yep looks good well done
as an aside cant see what you have done but draught excluder works best on the hinge edge on the door end and frame where it will compress rather than on the stop where the door can "roll it off"

Thanks for the tip, that's exactly what I did!
The biggest issue is actually along the edge of the step, as the step edge doesn't extend as far as the rails (about 1" short) and so the edge of the hatch. ended up letting some excess carpet extend past the lip of the hatch and folding it over, so it covers it when it's closed.

 

[big-all]

cant see clearly but assume the carpet has a join away from the trim on the other side off the ladder matching the flap but hidden by the timber and leg off the ladder

 

[Giblets46]

cant see clearly but assume the carpet has a join away from the trim on the other side off the ladder matching the flap but hidden by the timber and leg off the ladder

Think I understand what you mean, yes it's symmetrical to the other side of the ladder, I built a small 'box' either side of the ladder legs and cut the carpet all at this level, has the advantage of keeping the ladder stable and in the middle.
The edge is angled at the same angle of the ladder (and edge of the hatch matches this).
The gap under the step is the weak point in the insulation, but unless I was going to over complicate things it's the best solution