Yes, you can build tiny with natural materials! This 328 SF apartment was built on an existing garage foundation. The walls are super-insulating strawbales, so a small space heater keeps the whole place warm. The living roof ensures the space stays cool in summer.

All of the kitchen cabinets and bathroom fixtures were salvaged, including a full bath tub! A space-saving alternating stair provides access to the lofted bedroom with plenty of storage.