A communal rumah gadang is a long house, rectangular in plan, with multiple gables and upsweeping ridges, forming buffalo horn-like ends. They normally have three-tiered projections, each with varying floor levels. They are broad and set on wooden piles that can reach as high as 3 meters (10 feet) off the ground; sometimes with a verandah running along the front face of the house which is used as a reception and dining area, and as a sleeping place for guests. Unlike the Toba Batak homes, where the roof essentially creates the living space, the Minangkabau roof rests on conventional walls. Cooking and storage areas are often in separate buildings.
The rumah gadang is built in one of two basic designs: koto piliang and bodi caniago. These forms reflect different two variations of Minangkabau social structure. The koto piliang design reflects an aristocratic and hierarchical social structure, with the house containing anjuang (raised floors) at each end to permit elevated seating of clan leaders during ceremonial events. The bodi caniago design reflects a democratic social structure, with the floors being flat and on one level.
Large communal homes are entered through a doorway in the centre of the structure which is usually surrounded by a perpendicular porch with a triangular gable and upsweeping peaked ridge end. The variation with no entry porch is named bapaserek or surambi papek (“without veranda”).
Each element of a rumah gadang has its own symbolic meaning, which is referred to in adat speech and aphorisms. The elements of a rumah gadang includes:
- gonjong, hornlike roof structure
- singkok, triangular wall under the ends of gonjong
- pereng, shelf under the singkok
- anjuang, raised floor at the end of one style of rumah gadang
- dindiang ari, the walls on the side elevations
- dindiang tapi, the walls on the front and back elevations
- papan banyak, front facade
- papan sakapiang, a shelf or middle band on the periphery of the house
- salangko, wall enclosing space under a house that has been built on stilts