Attic
An attic storey is sometimes used instead of a second order, and this may vary from one-third to one-tenth the height of the order beneath it.
The attic may be quite plain, but it often has breakings or projections on its face corresponding to the vertical features of the supporting order.
It usually forms a storey in a building, and then is of necessity pierced with windows.
In architectural design the character and requirements of the building must, of course, be the first consideration, but the basement may constitute the ground floor, the height occupied by the order may contain two stories and the attic may be an upper floor.
When an order is not employed the divisions and proportions already stated may still be applied, the heights and widths should govern each other as would be the case if the façade were divided into bays by columns or pilasters.
In the absence of the order a cornice is substituted for the entablature, and this, according to different authorities, may be from one-twelfth to one-sixteenth the total height from the ground, but one-fourteenth or one-fifteenth will be found a safe mean.