Minecraft wiki entry for Roof_types, associated text: A saw-tooth roof has a series of ridges with dual pitches on either side. The steeper surfaces are glazed and face away from the equator to shield workers and machinery from direct sunlight. This type of roof is commonly used for deep plan buildings and factories. It may also be referred to as a northlight roof. Note that to be a 'proper' saw-tooth roof in Minecraft, the windows should all face North or all face South, and you should be consistent about which direction you choose.