Step 1: Tensile Structures
Most permanent buildings are made of materials that work well in compression, like brick and concrete. The weight of the building itself and the stuff inside it push down and compress the walls to keep it standing. Buildings that are made of compression materials are usually heavy. The Romans used a lot of stone. They were fans of compression.
A structure like your average camping tent works via tension - the space is enclosed by fabric that is stretched between a lightweight frame. You put stakes in the ground to pull on the fabric so it stays more or less in the same shape. When you think tension, think ropes and fabric. Some of the best rope-structure builders were the Incas. They built suspension bridges that spanned canyons and terrified their European visitors.
Wikipedia will tell you more about tensile structures.
One of the advantages of tensile structures is that you can span a very large distance without using a lot of material. This is why the longest bridges in the world are suspension bridges with a deck hanging from cables in tension.