Researching Your Old House: How to Find Original Brooklyn Row House Blueprints


What did your Brooklyn row house look like originally? What year was it built? Who was the architect? Was it a two-family, one-family or something else? These are all questions original blueprints can answer. You may want to know because you are renovating, you have a passion for old houses, you are a new owner or you’re just curious.

Finding your original blueprints requires some legwork, ingenuity and persistence, as Brownstoner reader chemosphere recently discovered when researching his house in Flatbush.

He posted about the process, what he found and questions about the 100-year-old shorthand he was trying to decipher in a few separate posts in the forum. He has kindly allowed us to use those posts and the pictures of the blueprints he found to discuss in more detail how to find and read your original blueprints.


Find your block and lot number.

The first thing you need to do is to find out the block and lot number of your property and every property in your row. You can do that by going to the City’s Department of Finance website, known as the Automated City Register Information System, or ACRIS, where property records such as deeds are kept.

Click on the second menu item on the home page, “Find Addresses and Parcels.” Type in your address address, then select “find BBL,” and the system will tell you the block and lot number.


Visit the Building Department.

The next thing you do is head to the Building Department at 210 Joralemon Street in Downtown Brooklyn. On the 8th Floor, fill out the form requesting any files available for every house in the row, using the block and lot numbers you have researched.

Give the form to a clerk. After about 15 minutes, you will exchange your ID for any files available. Many records have been destroyed in fires over the years, so original paperwork is not available for every address. If the building records still exist, they will often be grouped in one folder under one address in the row.

That is exactly what happened to chemosphere, who said:  “There was one file for my row of six houses.” He came up empty-handed on his own address but when the clerk checked under the other houses in the row, he struck gold.


How to read the blueprints.

Chemosphere found his two-story house was designed in 1909 and was originally a two-family house with two nearly identical floor-through flats. The house is very typical of row houses of the era one finds throughout neighborhoods booming with construction at the time, such as parts of Crown Heights, Bushwick, Prospect Lefferts Gardens and, of course, Flatbush.

Interestingly, the two interior rooms were identified as bedrooms, whereas the large room next to the kitchen was intended to be a dining room. This is very typical of multi-family apartments of the era, although it would not be allowed today, since legal bedrooms must have windows (or a skylight).

In addition to showing the original floor plan, the blueprints have a remarkable amount of other information. Chemosphere’s indicated what kind of wood was used in the various rooms: oak in the entry and “w wood,” most likely “white wood” or poplar stained or painted to look like a more expensive species, in the parlor. (Check out the details in this long thread.)

Also given in the blueprints are all the details of the facade, including windows and doors. If your house’s exterior has been altered and you would like to restore it, the blueprints are the best guide.

The blueprints also indicate the architect and the builders. In this case, chemosphere discovered the builders, Larsen and Anderson, were based at 336 Rutland Road in a wood frame house that still stands.


More info from the building permits.

In addition to the blueprints, your file may contain building permits. Chemosphere found that his had even more granular information. “The permits are incredibly detailed, including not only the size and material of the joists (3×8, spruce) but details like the original kitchen washtub (Alberene stone or soapstone),” he said.

If you do decide to search for these original documents, please update us on what you find. Happy blueprint hunting.


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