I just came across this:
There’s a rule of thumb that a building is considered attractively slender if it has an aspect ratio (which is to say, height to width) of 8:1.
Who came up with that? Is there an iconic building of precisely that ratio?
And what is the most attractive ratio of street width to building height? I seem to recall, from the Haussmann era in Paris, that the height of the streetwall was two-thirds the width of the street. Or was it the reverse?
If memory serves, Allan Jacobs (and others) observe that a 1:2 height-width ratio is necessary to create enclosure/definition. But I’m not sure if that was supposed to be an ideal, or simply a minimum.
And 2/3:1 is not far off from the Golden Ratio. Probabaly not a coincidence…
I’m a big fan of 1:1, although somewhat less than that (i.e., more width than height) is more common in Seattle neighborhoods and can work.
A classic discussion on scale is Hans Blumenfeld’s April 1953 article in The Town Planning Review, “Scale in Civic Design”, republished in the no doubt out of print collection of his writings, The Modern Metropolis: Its Origins, Growth, Characteristics and Planning, published by MIT Press in 1972 as an Open University paperback edition. This includes an extended discussion on the perceived effects of different scales, including the 1:1; 1:2; and 1:3 standard width/height ratios for streets and public open spaces. As one might guess, there is no “ideal scale” for every situation, but rather appropriate scales for the kind of spatial experience one wishes to create. Particularly interesting is Blumenfeld’s discussion of these scales in relation to the angles of visual perception of the human eye. Required reading for the budding urbanist.