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House History Research at The New York Public Library: CONSTRUCTION

A Guide For Researching the Histories of NYC Residential Buildings


One of the most common questions, and, potentially, one of the most difficult to answer, pertaining as it does to the identities of the person or persons who commissioned the construction of a building, and the person who designed it, the architect. If there was one.

If the building you are researching a is located in a Landmarked designated district. there is a good chance that it has been researched, and may be found in a historic district designation report. Discover NYC Landmarks Includes information about construction, and a link to the landmark designation report that the information is taken from.

The Office for Metropolitan History Buildings Permit Search: 1900-1986 is a great resource for discovering construction data taken from New Building applications at the Department of Buildings.  

Christopher Gray, founder of the OMH, describes the database: " the permits digitized there cover all of Manhattan [...] some addresses may be on a renumbered street, or by metes and bounds.  [...] [R]emember these are just applications for permits - the actual building might not have been completed, or been completed by another owner or architect. " 

Besides information in fire insurance maps, Landmark Preservation reports, and real estate news in newspapers and other periodicals, there are some records that prove useful when it comes to dating the construction of a building. Three of those resources are described in this section.

  • New Building applications
  • Property Tax records
  • I-Cards
  • Architectural guides

Bear in mind some records did not survive, so you may have to make informed estimates about dates of construction based on the information you have gathered from the sources that were available.


1877: Record of New Buildings inc. NB 175-77If you suspect a NYC building was erected before 1900, then you can visit the Municipal Archives, and consult their collection of The Manhattan Department of Buildings Docket Book Collection, 1866-1959 available on microfilm. You'll need the New Building (NB) number to search the microfilm, and this is found in the "Actions" section of a building's "Property Overview File," found on the Buildings Information System (BIS) database, mentioned below. Please be aware though, that the NB number may also refer to an alteration to your building. It is also possible that an application may be for a building that was never completed. The docket books, and original New Building applications, will include information confirming if an application led to a building being constructed.

For more details, see The Manhattan Department of Buildings Docket Book Collection, 1866-1959 / Kenneth Cobb [online].

The image below is a clipping from 1877: Record of New Buildings including NB 175-77, from the docket book collection. It collections information from the original application, including:

New Building permit No. 175, submitted by Carsten Gerken, April 2, 1877,  for a building 4 stories high, designed by the architects firm D. & J. Jardine, to be erected on the North West corner of 6th Avenue and Waverley Place. A building was to be made up of “French Flats,” with room enough for 3 families, built of brick, with a brownstone front, flat roof, cast iron cornice, stairs, and a fire-escape. The budget for construction is set at $15,000, and work was completed August 28, 1877.

Original applications might have survived in a Block and Lot folder for the lot. The Municipal Archives has Block and Lot folders (or files) for

North of 39th Street (Blocks 968+) Manhattan, and Bronx, Brooklyn, Queens, & Staten Island: NYC Department of Buildings

For further information see Department of Buildings - Manhattan Block and Lot Collection, 1866-1977 / Kenneth R. Cobb

For a comprehensive list of building related records at the Municipal Archives, see Department of Records, Records Group: Department of Buildings, RG 025.

Property cards

The 1939-1941 Tax Lot photographs already mentioned, were created as part of a W.P.A. project to record buildings "to appraise real property values for taxation in conjunction with a form that could be updated as real estate values changed. Together, the photos and the attached 8 ½ x 14 inch forms, known as property cards, that might include information about a date of construction. Even if they do not, the records are an invaluable resource for people researching buildings in New York City.

For further details, consult Tax Records and Time Machines: The Property Cards of the Municipal Archives / Kelli O'Toole

You can order copies of Property Cards from the Municipal Archives website.

Tax Assessment Records

The Assessed Valuation of Real Estate,1789-1979 records at the Municipal Archives can be used to estimate when a building was built, especially if it was built before 1866, and the creation of the Department of Buildings, or if no NB application can be found. Very broadly speaking, if a plot of land is assessed at a low rate one year, then a much higher rate the next, it follows that the property (the plot of land) may have been developed, i.e. a building has been erected on the lot.

For further information on using tax records to estimate when a building was constructed please consult How to Use Tax Assessment Records to Date Construction of a Building / Kenneth R. Cobb.


I-Card 79 Freeman Street If between roughly 1900 and 1935 your building was a multiple dwelling, with three or more residential units - or appeared to be one - it may have been visited by an inspector from  the New York City Tenement House Department, and the results captured on an Initial Inspection Card (aka I-Card). The cards, available online from the website of the New York City Department of Housing Preservation and Development describe the living conditions of the occupants, including information pertaining to light and ventilation, fire safety, plumbing, and sanitary facilities, interior layout, and more besides. They sometimes include a New Building (NB) number and a date of construction.

The cards may include a floor plan. Right is an I-Card, including  floor plan, for a frame house in Brooklyn made up of 3 apartments. The floor plan describes a different layout from the one that exists today. Search the HPD website using the building address and select "I-Card" from the menu to the left of the results. Some I-cards also give information about the building's date of construction.

See this article for more information about the history of I-Cards.

If no records describing a building's date of construction are available, it may be possible to make an educated guess using census records, city directories (to date approximately when a building may have been inhabited), property deeds, newspapers, and guides to architectural style. 

The NYPL Art & Architecture Collection (Room 300), part of The Miriam and Ira D. Wallach Division of Art, Prints and Photographs will include numerous guides to styles of architecture, and information about architects: you can contact that division for further advice.

See also, NYPL New York City Architecture: How to Research a Building, a great guide that focuses on architecture.

Search in the NYPL Research catalog for reference materials pertaining to the history of housing in New York City. Some examples of useful subject terms include:

The New York Landmarks Preservation Commission Row House Manual is a really useful online guide to the history of NY row house styles that you can use estimate a building's age. Particularly useful when researching Brooklyn brownstone buildings where no Notice to Build application exists.