From Shinto Shrines: A Guide to the Sacred Sites of Japan's Ancient Religion
Gongen-zukuri: Also called ishinoma- and yatsumune-zukuri, this style incorporates the honden and haiden under a single, complex roof. The irimoya-zukuri haiden and irimoya- or nagare-zukuri honden are connected by an intermediate space called the ainoma or ishinoma (reflecting its physical form) or heiden (reflecting its use), with the roof ridge of this space running perpendicular to the other roofs so that they form an I or an inverted T shape when viewed from above. (The view depends on the size of the ainoma relative to the other two structures.) The haiden has wings with slightly lower roof heights attached to the left and right sides. A gongen is a Shinto kami considered to be an avatar or manifestation of the Buddha. The style was named for Nikko Toshogu, where Tosho Daigongen (Tokugawa Ieyasu). The Buddhist-influenced structure is usually lacquered inside and out. In the case of Toshogu shrines, the style is highly elaborate, with carvings of fantastic animals and metalwork in copper and gold.
The following styles are primarily associated with the shrine from which they originate. Thus a sumiyoshi-zukuri style will only be found on Sumiyoshi shrines.
Sumiyoshi-zukuri: This style of honden has a gable roof with the entrance in the center of the gabled side. The structure is two bays wide by four deep. The roofline is flat and has a deep overhang on all four sides. There are katsuogi and very tall chigi. It somewhat resembles the shinmei style but all thesukiden structures