"Northern range aparently conceived by builders after walls, and possibly vaults, of central and southern ranges had been built. Old north wall then thickened, in accordance with custom of making interior walls heavier than outer in order to carry weight of two vaults, and northern range built. Balanced design of decoration on east facade suggests facing of upper facade not applied until all vaults had been constructed, but may have been dismantling and rebuilding."
H.E.D. Pollock, The Puuc: An Architectural Survey of the Hill Country of Yucatan and Northern Campeche, Mexico, p. 64