Much has been written about the way the Zoning Resolution has reshaped the form of new buildings – from the wedding cakes of 1916 to the towers in the park of 1961 to the contextual buildings of the 1980s, to the present day. Each generation of zoning regulations has shaped the following generation of new buildings. But, as each year it becomes more true to say, most of our buildings are not new. As the city has continued to mature, how should its zoning regard the role of buildings that predate these regulations?
The last century of zoning has seen an evolving approach to the role these regulations can and should play in the upgrading and repurposing of existing buildings. There has always been an acknowledgment that older buildings will remain part of the city’s fabric, whether they meet all current standards of zoning or whether, as “non-complying” buildings, they do not. But increasingly, there has also been recognition of a number of circumstances under which existing buildings should be granted additional latitude to be modified or reused to support continued investment and promote a range of public policy objectives.
Since its origins, zoning has allowed existing buildings to be modified in certain ways to achieve other objectives of the zoning. For example, in 1961, nonconforming uses—particularly manufacturing uses in residential areas—were seen as “the worst type of non-conforming uses,” for which “no regulation short of termination offers anything approaching a real solution.” So the 1961 zoning was broadly permissive of the conversion of existing manufacturing buildings to housing in residence districts, even where this meant that existing non-compliances with current bulk regulations would persist. Elsewhere, it was expected that many older noncomplying buildings would remain, even as slum clearance and urban renewal efforts continued within significant swaths of the city:
Similarly, with the introduction of landmark preservation regulations in the late 1960s, special permit provisions were established to allow changes in bulk or use that would not otherwise be permitted under zoning, where this would facilitate preservation of the landmark.
Later, in 1981, provisions were established for six Manhattan Community Districts (later extended to six additional districts in Brooklyn and Queens) allowing residential conversion of existing noncomplying buildings, even if the buildings were not occupied by nonconforming uses. This provision was intended to enable the adaptive reuse of scores of buildings that otherwise might have otherwise have fallen into disuse and disrepair, or that would require more disruptive demolition and costly reconstruction. It too acknowledged that existing noncompliances can play a role in the fabric of the city.
While the 1961 zoning generally did not allow increases in the degree of noncompliance with bulk regulations, it did make accommodations for modifications to address other targeted goals, such as improving the safety of buildings. Thus it allowed, for instance, the addition of fire escapes to existing buildings. In more recent years, additional accommodations have been introduced to further other public policy goals. For instance, the 2012 Zone Green amendments to the Resolution allowed items such as rooftop solar installations, shading devices for windows, and exterior insulation to be added to existing buildings, recognizing that the environmental benefits of such elements exceeded any detriment from minor increases to a dimension of a building. The 2013 Flood Resilience Text Amendment and 2015 Special Regulations for Neighborhood Recovery recognized that the continuation or extension of a noncompliance was of lesser concern than the risks of flood damage to individual buildings and coastal neighborhoods. These changes allowed additional flexibility for vulnerable buildings in flood hazard zones to be elevated or reshaped in minor ways that would not otherwise be permitted by zoning, provided that they meet the latest standards for flood-resistant construction.
The City continues to identify additional circumstances in which existing buildings can be afforded additional latitude to upgrade them. For instance, in East Midtown, there is a recognition that many existing overbuilt office buildings are obsolete but cannot be upgraded without being rebuilt, and that zoning discourages this from happening. As part of an ongoing planning process for the area, targeted changes are being explored to enable these overbuilt buildings to be rebuilt to meet modern office and environmental standards while retaining the full floor area to which they are built.
In 1916, the city was in the midst of a period of explosive growth that, as widely recognized at the time, would dramatically change its shape and size. In 1961, the city was not expected to grow substantially, but planners still envisioned wholesale replacement of large portions of the city’s fabric. Today, we recognize that the city is unlikely to be rebuilt wholesale – about 90 percent of the buildings we expect to have by mid-century already exist. But as part of this evolving view of our built fabric, there is also a growing recognition that if buildings are not going to be replaced, they will still need to adapt and upgrade. After all, in the world’s most dynamic city, even old buildings need to be able to keep up with the times.
 Voorhees, Walker, Smith & Smith, Zoning New York City, 1958, p. 229
 Ibid, p. 230
Howard Slatkin is the Deputy Director for Strategic Planning for the New York City Department of City Planning.