The Sumbiani church is built of brick, with cobblestone used here and there. The church is a domed building (7.5 × 5.53 m) with two entrances: one in the middle of the west wall, the other in the western part of the north wall. In plan the hall forms a short-armed rectangular cross, extended on the east by a bema and apse. On either side of the apse window is a small niche. The transition from the square under the dome to the circular drum is made by pendentives. Outside, a tall window is cut in each facet of the octagonal drum; the drum's lower part is blind, while its upper edges are ringed with a brick roll molding. The drum is finished with a segmental cornice.