On density and design tradeoffs

Bethesda Row - note that you don't even see how tall the buildings are - CC image from faceless b

Kaid Benfield’s excellent blog had a post last week on the need for better urban design and management of the public realm in our new, dense infill development. And while I certainly agree with the need for better urban design, I take issue with Kaid’s implication of an explicit trade-off between density and design – that is, the more density you get, the less human-scaled the street will feel as if this were some correlation of a natural law.

Kaid’s post shows several comparison photographs taken from Google streetview, many from the DC area.  What’s missing is an actual accounting for the density embodied in those pictures (such as the visual survey posted here). Additionally, some of the photos Kaid compares are not similar photos – one example involves a view down the axis of a street, while the other is a view of a building’s first floor and the accompanying sidewalk.

For me, it’s a completely different feel.  The second development, part of Bethesda, Maryland’s terrific Bethesda Row area, is not just more inviting but also a bit smaller in scale, at five or six stories tops.  But that’s part of it, in my opinion.  To increase density enough to make a difference, we don’t always need to maximize it.  Much of the time a moderate amount of human-scaled urbanism will be far more appropriate than a high-rise.  This isn’t, or shouldn’t be, just about calculations of units per acre or square footage.  It’s also about what feels right to people.

The sentiment that “we don’t always need to maximize” density implies a tradeoff between human-scaled design and density that I don’t think is absolute.  To a great degree, the influence of design – at the street level in particular – is the key element of a human scale.  In the comments, Payton (assuming this is from Payton Chung) adds this:

I’d agree that it’s almost all about design. The low- and mid-rise floors are most important, to be sure, since humans’ peripheral vision is weakest when looking up. However, there are plenty of historic skyscraper districts that maintain a great sense of place and small scale at the street level (Broadway in Los Angeles is a thrill to walk down), and even some which maintain good sunlight at street level (just was at Rockefeller Center for the first time in a while and reminded of that crucial detail).

Encouraging both smaller parcel sizes — for exactly that granularity, and to ensure greater diversity — and mid-rise heights both ask huge concessions from our current bigger-is-better development paradigm. Of course a developer will build out to whatever envelope the regulations will allow to recoup their costs, will charge high initial rents that only the most reliably profitable (i.e., bland) retailers can afford, and often won’t spend a premium on the sort of pedestrian-scale details that really create a great sidewalk environment. Yet other factors also result in these squat, boring buildings. Occupants will pay a premium for “ground-related” space or for high-rise space with a view, but not for the mid-rise floors. (Compare that to the 18th and 19th centuries, when the 2nd floor commanded the highest rent as it were above street dust but not a long walk up.) High-rise life safety and structural requirements make a 6-story building almost as expensive as a 12-story building. Requirements for exit stairs (like restricting scissor stairs), and tenants’ desire for reconfigurable spaces, both fatten floorplates. Municipalities set build-to lines for bases (correct) and, fearful of oddly height-obsessed NIMBYs, set unrealistically low height limits.

For things like sunlight at street level, the more important considerations would be the orientation of buildings on the site and the setbacks rather than absolute height – issues of design of a different sort than the street level scale.

2 comments to On density and design tradeoffs

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