Thanks for all the comments.

Now, Andy / John, how did you finish off the eaves edge of the roof.
You've got rafters topped by ply, did you just let the felt form a drip
edge? Into a gutter? Did you doing anything to the ends of the rafters,
seems they'd be vulnerable to getting splashed from the gutter.

I think John mentioned in a post (or his excellent) site that a 30deg
roof looked wrong. That's what I was planning, but having looked e.g.
next door's summer house shed (off the peg style one) with a shallower
roof angle, I think you may be right. I'm now working on 22.5deg (next
stop on the mitre saw), lowers the ridge ~200mm and means I get 3
rafters out of a 4.2m length of timber.

The current material list includes 210m of 3x2, 285m of cladding and
285m of T&G floor / roof. Eeek. Over £1500 at list prices for all the
materials so far, so next its shopping round for a job lot price.


--
Steve