A capitol-type building is a monumental building dominated by a high open vaulted or domed space on the central axis. Buildings in this category may have regular floor divisions in their wings, as long as the high space rises significantly higher than the roof of the wing.

This building type is secular; a number of churches and other religious buildings are built in this form, but remain classified with religious buildings. Multi-story buildings with atriums are not classified as monumental halls.

The central high space dominates even when the wings contain regular floors. A multi-story building with an atrium has a different overall form, and a religious building retains its separate type.