[Shop-talk] Building/adding a deck cover?

[Obaa]

Thanks for the comments guys.

It sounds like there are some mixed opinions on this stuff, but dependent on the material?  I'm specifically planning on using the translucent white polycarbonate stuff, not the ondura roof panels.  It seems like these are okay?
Is the concern with the wind-loading due to the top swaying?  The bottom of the posts will be anchored to the deck.  I had hoped to leave the top unattached due to the permitting issue.  (I'm also reluctant to cut through the siding since we have the "bad" LP chipboard siding.  I know I need to replace it, but it's been holding up so far, and we were planning on getting the addition done at the same time as the residing.)  I thought if I triangulated the support posts at the top, that would be sufficient to keep the top from swaying; maybe a few lag bolts into the house would help?
Is there more loading on an open structure like this than a fully enclosed building?  I would think the wind could just blow through it, while an enclosed building would have more of a sail area.  Or is there some lift going on that I haven't accounted for?  If the panels themselves are too flimsy, I can "box" the bottom of the trusses with some 1/4" plywood (I have a lot of that); then the loading would only come from the top.
I'll try the google sketch-up.
Any other ideas or comments, please let me know.

Thanks!