Wood for it's insulation value, you can buy vinyl covered wood frames also.
I built my pergola out of Fl cypress it's great.
But I will use cypress for the frames, but they will be finished with a bronze color stain on the exterior and left natural interior.
Before the glass is set all the frames will be finished with a marine grade high UV finish 4 coats, should last 5 years out side indefinably on the interior.
If the exterior is re-coated as needed it shouldn't be a big job.
But the look should be great.
My architect is stopping by tomorrow to start the plans.
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