Thanks guys.
David -- Have tried the soffit tool using the sloped option, even found a KB article (http://www.homedesignersoftware.com/support/article/KB-00902/) that says "Angled timber members can also be created in the Home Designer Architectural and Home Designer Pro versions by using a sloped soffit.", but doesn't do much to explain how.
Mick -- The truss on the front is a stock truss with the king post option checked. It happens to match the design I'm trying to replicate. Your suggestion is what I tried first, but because of the width of the building, the truss generated has too many members.
I'll keep trying.
-- Eric