This document defines buildings and houses, then classifies buildings by use. It discusses residential buildings in depth, describing types like single-family homes, duplexes, apartments, condominiums, townhouses, villas and bungalows. It also examines residential buildings by income level and lists typical rooms in houses like living rooms, kitchens, bedrooms, bathrooms, dining rooms, verandahs and garages. The document provides an international case study of a residential building in Colorado and a local case study in Ethiopia, noting merits and demerits of each.