This document discusses housing styles around the world and how they are adapted to different environments and available resources. It provides examples of houses made from materials like mud, reeds, snow, and describes why certain styles developed. For instance, it notes that Swiss chalets have large roofs to protect against heavy snowfall in winter. Mud huts can still be seen in parts of Africa as they are inexpensive and cool. Some people live in tents because they are nomadic and need to relocate frequently.