I learned something interesting about Bermuda on a recent trip there. They have beautiful pink sand beaches but no fresh water on the islands. To supply their homes with safe water for drinking and washing they make good use of their roofs.
In the photo here you can see a pyramid-like shape to the roof, used to catch rainwater and direct it to a pipe running alongside the building. Instead of basements they build their homes on top of huge water tanks. Bermuda is relatively free of pollution but the roofs are treated with a limestone wash that purifies the water.
Note also in this photo that the shutters open upwards to allow the fresh air in while providing protection from the sun.
Image by April Colosimo