That was in response to Mayor Gray’s announcement that the Zoning Commission would not close its records until September 2014, so we weren’t able to share as much as I wanted. Here’s more:
Barton-Aschman were hired by the pre-home-rule Walter Washington administration to examine the code after the MLK assassination riots, Urban Renewal, the Metro, and freeway revolt. Not all of their comments were negative, but the technocratic, autocentric attitude that ran through the 1958 process was nowhere to be found.
These events had big impacts in the ideologies of the planning community. So, just 12 years after the code was passed, they saw a code that was plagued by assumptions that no longer applied and solutions that only seemed to make things worse:
A considerable number of provisions are archaic or substandard and need to be systematically reviewed and modernized. New techniques should be developed to accommodate changing market demand, technological advances, and new social conditions and programs.
Some things changed after this report was published. Parking minimums got lower. Much of the city was downzoned. Overlays were used to make custom tweaks. A more general PUD was introduced. And certain downtown zones became more open to residential uses, making it less of a nighttime wasteland.
Still, some of the ideas these planners found outdated in the Nixon years are still are at the root of the problems the city faces today.
They found fault with Lewis’ absolutely separation of commercial and residential uses, which underlies the ban on corner stores. They noted that the then-planned Metro system justified higher densities downtown and less reliance on automobiles. They saw how the zoning restrictions made it hard to build enough housing for a growing city.
They foresaw the problem with restricting housing supply:
Studies for the original code by its principal author, a planning consultant named Harold Lewis, predicted that 870,000 people could live in DC under his zoning regimen. But that assumed large families and urban renewal instead of historic districts. The 1970 report notes:
It is possible that zoning makes it difficult to develop new family-type housing units in the district, while also inhibiting the development of high-rise apartments which may be more attractive to single persons and families without children…. if zoning helps deter population growth, is it contributing to an imbalanced society in the District?
They further noted these restrictions would push out the middle class, “leaving predominantly the rich and the poor of both races.” They note that this is not a local fluke, but one that is recognizable nationwide:
The Douglas Commission has pointed out that existing codes and ordinances of major cities across the country deter the development of low-cost housing by private industry. Land is too expensive, parcels are to small, height and floor area ratios are too low, and density patterns are too restrictive to encourage modern, attractive, and livable low cost residential projects.
These problems have been exacerbated by aggressive downzoning to preserve the character of outer neighborhoods. The report noted the potential for this problem, writing, “local residents might stretch the zoning process to become exclusionary.”
They realized that Metro changed everything:
Barton-Aschman’s 1970 report was blunt about how the Metro system would change the city:
Perhaps the metro system alone is a sufficiently important factor to justify a complete review of policies assumed in the 1956 Zoning Plan and reflected in the existing Zoning Regulations.
Harold Lewis, the planner who wrote the backbone of the 1958 zoning code, assumed that there would be no mass-transit system. At a public hearing on July 28th, 1956, he justified his plan:
Washington has, of course, a free choice as to which means of transportation it wishes to dominate the central city, … no new transit system can possibly start operation for several years at the earliest, and it is therefore obvious that the  zoning must be based on solid present trends and solid present fact.
Those trends were declining transit ridership and an extensive network of highways that were soon to snake their way through Washington’s neighborhoods. For Lewis, the Inner Beltway had a second purpose. It would be a great “dam” that would forever keep downtown’s commercial uses from bleeding into residential neighborhoods – at least the ones that survived highway construction.
I don’t know what Baron-Aschman would approve of the proposed
2013 2014 zoning code. But I think we can see that the ideas proposed by Harriet Tregoning and OP aren’t the product of some novel ideology. They came out of realizations that midcentury planning assumptions didn’t quite work in practice. The patchwork of overlays and tweaks hasn’t changed enough.