The façade of Santa Maria Novella, Florence , Italy , by the renaissance architect Alberti can be analysed in terms of proportions which are quartered, halved , doubled or tripled. It can be circumscribed by three large and equal squares , two side by side at the base and one centrally placed above . If these squares are subdivided into quarters we have the dimensions of the scrolls which flank the upper storey . The entrance bay is composed of six squares which are a quarter of the size of the squares used to give the dimensions of the scrolls; the height of the entrance bay is one and a half times its width. Further subdivisions reflect the same ratios and nothing can be added to or taken away from the façade without destroying its harmony.