ORDONNANCE, in architecture, is the composition of a building, and the disposition of its parts, both with regard to the whole, and to one another; or, as Mr Evelyn expresses it, determining the measure of what is assigned to the several apartments. Thus ordnance is the judicious contrivance of the plan or mould; as when the court, hall, lodgings, &c. are neither too large nor too small, but the court affords convenient light to the apartments about it: the hall is of fit capacity to receive company; and the bed-chamber, &c. of a proper size. When these divisions are either too great or too small, with respect to the whole, as where there is a large court to a little house, or a small hall to a magnificent palace, and the fault is in the ordnance. See ARCHITECTURE.