I'm trying to decide on window treatments for our Great Room (photo attached), which is still under construction.

The windows face north and our backyard which is a meadow surrounded by mature trees. I'm trying for a light, breezy look that lets in the light. The windows are high quality so drafts should not be an issue,

I'm thinking about metal curtain rods and light textured sheers or light textured curtains. The length of the curtains would be just below the sill -- due to the electric baseboard heat. On the two tall window units, the rod would go across the trim between the lower rectangular window and the upper trapezoid window. I'm planning matching floor-length curtains on the patio door. I'm not sure whether to go with 1/2" diameter or larger 1.5" diameter curtain rods.

Suggestions?