I've just given a 3D model (example screen-grab below) of our intended roof design to a large local framing company.
The original model was made up in Sketchup and converted to DWG for them to read & edit it in Autocad.
They supposedly completed it for referral to Finnjoist for assessment/approval/sign-off and for recommendations on fixings etc.
I've just heard back that Finnjoist say:

"Due to the interaction of the new roof with the existing building and the nature of the hip ends they feel that it would be best for the design and detailing to be completed by the building designer/engineer."

I'd expected Finnjoist to be the roof element "building designer/engineer" in effect.

I have the finnjoist PDF's on recommended approaches to joints, plates, shims etc and can use these to work the plan up further into more detail.
However, in the absence of a "building designer/engineer" I'm going to need examples of other existing structures that demonstrate the structural integrity of what we're planning, through their use of comparable joist dimensions at comparable centres over comparable spans with comparable tie-ins etc etc ....

This is to confirm for myself what I know through having worked with timber,
but also in case Building control question it.

Any offers or suggestions would be very much appreciated.
Thanks,
Mike.

Dickster, I don't think that would be too late anyway but do you have plans for it already?
I can over-engineer it of course but that has cost implications and also I'm trying to keep parts of the space open to the room below which means avoiding ties (other than those shown in purple and yellow above) if at all possible.
I think Finnforest do some software for calculations but I will probably not be up to using it correctly ...
Have this idea n my head that having some sort of precedent will be best if the BC inspector is not familiar with "I" beams used in a hip roof.

Perhaps I missunderstand your drawing. Can we see other views?

Ah I see you have purple lines/ties on the top of the joists. So those are in tension. My guess it they are concerned about the interaction between their bit and the existing house which presumably they haven't see.

It's a good point. An SE might simplify the design saving more than his own fee.