Minecraft wiki entry for Roof_construction_guidelines, associated text: It is possible to make buildings in Minecraft that aren't aligned with the four cardinal directions. Unfortunately, except at very large scales, it is hard to make them look convincing. If you are constructing a metropolis, the occasional odd-shaped building helps enormously to add variety to Minecraft's regimented grid, but normally making these buildings is not worth the extra complexity. The example above is diamond-shaped and uses slabs for its roof. Normally, non-axis-aligned buildings should use slabs or blocks for their roofs, as stairs are often awkward to manage.