I agree with the other posts. That sunlight coming thru those windows even tho it might be indirect will fade your fabrics and is the culprit that warped your rulers. It is the heat generated from that sunlight. Sunlight is great for sewing but keep your fabrics hidden from it otherwise some will fade. I know that from experience. I didn't realize that my collection of reproduction prints, mostly Aunt Grace's, were faded by indirect sunlight that occurred for only an hour each day. NOW, I am much more cautious with dealing with sunlight. It can be your friend and enemy.