Department of Buildings

Architectural Plans and Drawings

The history of building regulation in New York City dates almost as far back as the city itself. In 1625, the Dutch West India Company imposed rules regarding the types of structures that could be built and where they could be located.  In succeeding years, additional regulations were enacted that addressed fire hazards, as well as sanitary and public safety needs, but enforcement was inconsistent.

By the 19th century, overcrowding became a significant problem. The city’s population expanded from 60,000 in 1800, to more than 800,000 in 1860. Many single-family buildings were altered to accommodate multiple households; additional buildings were “back built” into their existing small yards.

As the population continued to increase and the City’s economy grew in complexity, the need for larger and more versatile buildings became critical. The introduction of new technologies such as the elevator and steel-frame construction allowed ever-larger and taller buildings to rise along the narrow streets of Lower Manhattan.

The city’s exponential growth, and the increased demand for regulation and documentation, led to new laws that regulated construction and, in 1866, establishment of a Department of Buildings (DOB). The DOB implemented an application and review procedure for both new construction and alteration work on extant buildings.

During the last decade of the 19th century, the City devised the block and lot numbering system to uniquely identify every real estate parcel. The DOB adopted this scheme and began labeling all plans and permit application paperwork with the relevant numbers and filed the materials accordingly.

The Municipal Archives staff have recently worked to improve conditions of the plans through conservation treatments and preservation housing.  The selections in the gallery  here present a unique view of the varied types of plans in this collection.  If you would like more information, email research@records.nyc.gov.