My sewing room is approx. 10 x 13 sort of the same size as yours and although it is a little on the small size, it's on the lst floor which I love. Only 1 window in mine but if I were you, I would prefer the natural light. I keep and store lots of my fabrics in the basement in see through totes and they keep beautifully. Makes more room for me this way in my sewing room...