tucker,
In my work, I send something like what you have now to my engineer. He uses sketchup, so a basic model with the right building size and shape and the pieces where i want them is all i need to work it all out with him. That is of course after I have the job. Which means, usually, that I have already priced it without his input. Not a good way to do things if you don't know what you're getting into. I have a good enough relationship with him that if something really weird comes up that I'm pricing, I'll run it by him and he will give me some input off the clock to help work out the tricky parts so I can estimate it accurately.
So if you have the job or it's your carport, now isn't too soon as long as the size and shape of the building are pretty well determined.
I completely agree with Mike on this one -- hire an engineer who knows TF.
