Mystery at 7th Avenue & Union Street

The northeast corner of 7th Avenue and Union Street is occupied by a handsome block of four mixed-use buildings (flats over stores) in a vaguely Neoclassical style:

83-87 7th Avenue (Park Slope Historic District); 89 7th Avenue (unprotected)

The row exemplifies the schizoid boundaries of the original Park Slope Historic District, designated July 17, 1973: the three buildings on the left (83-87 7th Ave.) are in the current historic district, while the building on the right, at the Union Street corner, was left out, even though all four buildings were clearly designed as a unit.

We know from our Documentary History of the Park Slope Historic District Expansion that the parcel of four building lots came into the hands of prolific Park Slope builder Louis Bonert in 1896. Bonert purchased the lots from the executor of the "Morrison estate" and immediately filed plans, prepared by architect Robert Dixon, for four mixed-use buildings, the interiors of which were to be "fitted up in the finest manner and have every modern improvement".

Brooklyn Daily Eagle, January 22, 1896, p.12 ("Real Estate Market")

New York Times, January 23, 1896, ("Brooklyn Realty Matters")

Brooklyn Daily Eagle, April 24, 1896, p. 13 ("New Buildings")

Building Intelligence; Houses; Brooklyn, N. Y.,

– "Seventh Ave., n e cor. Union St., 4 four-st’y brick dwells., one 27' 6" x 90', one 21' 8" x 62', two 20' 6" x 62', tin roofs; $42,000; own., Louis Bonert, 321 Tenth St.; arch., Robert Dixon, 213 Montague St."

American Architect & Building News, vol. 52, no. 1062 (May 2, 1896): p. 2

The buildings exhibit a number of characteristics similar to other buildings erected by Bonert, including the arched windows at the 4th floor and the decorative panels below some of the windows:

One of the most distinctive characteristics is the unusual tripartite windows at 85 7th Avenue. These windows are found on only a very few other buildings in Park Slope, all associated with Louis Bonert, standing in 3rd Street between 5th & 6th Avenues.

85 7th Avenue - detail

408 3rd Street - detail

Alas, the Bonert attribution appears to be incorrect. Since three of these buildings are within the current Historic District, we can consult the existing Designation Report, which maintains that the buildings were erected in 1901 by builder Leo W. Winkelman to plans by architect M. J. Morrill:

Park Slope Historic District Designation Report, p. 12: "83-87 7th Avenue"

We have been trained to consider the current Designation Report to be infallible (although we have identified at least one omission in it), so we can only assume that Bonert's plans for this parcel were quickly aborted for some reason; that the property was transferred from Bonert to Winkelman some time between 1896 and 1901; and that the similarities of the existing buildings to Bonert's other buildings are merely coincidental. We have found no information documenting the property transfer from Bonert to Winkelman, and no building permits issued to Winkelman for these lots.

The narrow entrances to the flats above, up three steps from the sidewalks, flank the original commercial spaces on the ground floor.

The corner building at Union Street is within the first phase of the proposed extension to the Park Slope Historic District, so one hopes that it will soon obtain the historic district protections enjoyed by its immediate neighbors to the north.

83-87 7th Avenue (Park Slope Historic District); 89 7th Avenue (unprotected)