Perimeter continuity

Each new level in a framework, developed by extension of a pattern of inter-level connections, is defined and given form by connecting these together to form a continuous perimeter ring. This helps to resist distortion resulting from the new level partly by redistributing forces from that level to maintain the overall structural integrity.

If a room is conceived and built by first placing columns at the corners, and then gradually weaving the walls and ceiling around them, the room needs a perimeter beam around its upper edge. This resists the horizontal thrust of the vault above, spreading the loads from upper stories onto columns, tying the columns together, and functioning as a lintel over openings in the wall.