Hi Mark,

For years we have been using a per board foot basis for estimating frame costs and it works well for us. Our feeling is we are timber framers so we base our price on how much timber we frame. Depending on job size, timber species and complexity of joinery we use $7-9/BF (US). I don't know how well that works in your situation but it would at least give you a WAG at the cost for framing.

The other issue you need to address is how the roof insulation sytem will work. If it's SIPs, they don't work all that well on trusses.

Rudy