3: 69 and 70 Dean Street
As you now know, the Georgians loved the ancient temples of Greece and Rome. This love developed into academic theories of proportion and symmetry, and the front of your house had to obey these 'rules' if anyone was going to take you seriously. The square, in particular, was considered the key to architectural beauty.
Squares
Proportions based on squares were used to determine the size of windows and their relation to each other. If a town house was three bays wide (in this instance, bay means window), then the space occupied by the first and second floor windows should form a square.
You can see this square rule on number 70. The square of six windows sits between two pilasters and below the rather grand cornice (ignore the warehouse windows above the cornice, this was a late 19th century renovation when the building was a printing house. The sill bands would also have been a later addition).
This square and sense of measured proportion is especially apparent when compared with the visual chaos at number 69. The distance between windows is all over the place, possibly due to renovations at one time or another.