Along Allisonville Road north of 65th, a fair number of houses were built on 1-2 acre lots. In several cases over the past 10-20 years, the original house has been acquired by developers who re-divided the land into 4-6 McMansion lots.

While it is definitely not my cup o’ tea, it is one model for densification of the inner ring.

I believe this desperately needs to occur on a national scale, however, with a lot of thought and care. I worry about one city nobley adopting such policies, and “losing out” to similar cities in their region who continue sprawl development. (I suspect soneone could cite examples where this has already occured.)

Keeping residential density modestly high (much higher than what exist in many of the older American cities) within a mile or two of the central business district is key for their viability, IMO. The allure of “new” offered by many growing suburbs is artificial and fueled by the developer and land owners, understandably operating within the rules of American commerce. Though many cite the city as “no place to raise a family” far too many who are single (whether young, divorced, or elderly) still remain suburban bound. I don’t know what the next idea in creating that demand for the city is, tough I suspect shutting down the ruse of “new” means “better” and therefore you are “better, too” has to be done. (I like cities, so I am biased.)

Lest you think that that has nothing to do with this series, that we have to figure out what to do with aging suburbs also, my point is that exurban sprawl has to be stopped before any sort of retrofitting looks good enough to be feasible (economically and politically).

Instead, we’ll probably just keep on building giant lot suburbs, then wondering how to handle them once they age. If that goes on, all of Aaron’s good advice contained here will not only fall on deaf ears, but it will be irrelevant, since no one wants to make the hard decisions till they have to do so. Create some sort of urban growth limits (not necessarily Portland-style), and market forces will make the retrofitting begin (though rezoning as Harrison suggests is key).

It’s the lot size and configuration that makes suburbs unwalkable.

In addition, a Brookings study comparing land use in the US and Germany says that in Germany, residential zoning regulations already allow many home-based businesses, such as doctor’s offices.

Neither German cities nor New York has any requirement that single-family homes in mixed-use subdivisions be very large and imposing. That would be counterproductive – large suburban homes tend to make pedestrian experience worse.