Window treatments help minimize heat transfer from windows. Drapes, blinds, shutters, and shades can all block sunlight from heating up the house on hot days and keep warm or cool air from escaping through leaky windows. Look for eco-friendly fabrics such as organic cotton and hemp, and shutters made of FSC-certified hardwood. Avoid plastic shutters and blinds, as well as polyester fabrics that won’t biodegrade. Woven shades made of bamboo, reeds, and grasses are another green option, as long as they aren’t treated with oil-based finishes.