"[R]esearch shows that the benefits of density are not linear, but taper off as density increases. In other words, there is an optimum density, above which the negative effects of density start to increase over the positive ones. That "sweet spot" seems to be in the neighborhood of about 50 people per acre. And many cities around the world achieve this density without tall buildings, and while creating a very appealing, livable environment (e.g., Paris and London, as well as the aforementioned parts of New York, Vancouver et al.)."Now, since people per acre is an unreliable predictor of form, and because the negative characteristics of tall buildings Mehaffy describes are mostly attributable to their form, rather than their population density (if any, in the case of office buildings), it would be interesting to see numbers couched in terms of floor area per acre, ground coverage and building heights rather than population density. One of the studies cited in the article mentions a six-story "sweet spot," and the House of Commons report includes illustrations of a few hypothetical configurations, but this is an area that deserves further exploration.
Friday, February 25, 2011
Mehaffy on Skyscrapers
Over at New Urban Network, Michael Mehaffy has posted an in-depth account of the drawbacks of tall buildings, echoing some of the points made here previously but with much greater depth, detail and scholarly support. Most interesting to me is the suggestion of a density optimum, a point at which density and livability are maximized while minimizing construction costs and other negative externalities of tall buildings: