The Offerman Building is a historic building at 503–513 Fulton Street in the Downtown Brooklyn neighborhood of New York City, New York, U.S. Designed by Danish architect Peter J. Lauritzen in a Romanesque Revival style, the eight-story building was built between 1890 and 1892 as a commercial structure, housing the S. Wechsler & Brother department store. Although the lower stories remain in commercial use, the upper stories were converted into a 121-unit residential complex in the 2010s. The building is a New York City designated landmark and is listed on the National Register of Historic Places.

The building has three distinct sections: the original wings on Fulton Street to the south and Duffield Street to the east, as well as a three-story glass annex on Bridge Street to the west that dates from the 2010s. On the Fulton and Duffield Street wings, the first and second stories of the facade are clad in stone, while brick and terracotta were used on the upper stories. The Fulton Street wing is mostly seven stories high (except for the central eight-story section), while the Duffield Street wing is six stories high. Inside, the building was originally used in its entirety as a department store, with various selling departments on each floor, as well as a small mechanical plant in the basement. The building's interior has been rearranged multiple times throughout the years; by the 2010s, only the basement and first two stories remained in retail use.

The building was developed by Brooklyn Sugar Refining Company president Henry Offerman, who agreed in late 1889 to lease the entire structure to S. Wechsler & Bro. (later Wechsler Bros. & Co.). The Offerman Building opened on May 1, 1891, and was expanded along Duffield Street in 1892 after the store's business grew significantly. Wechsler Bros. & Co. occupied the building until 1895, when Offerman took over the store. Joseph H. Bauland operated the store from 1897 to 1903, and Chapman & Co. then operated the store until 1907. The structure was then used as offices from 1909 to 1922, when Martin's department store moved into the building. Martin's occupied the Offerman Building for nearly six decades, moving out during 1979, after which the Laboz family's company United American Land bought the building. In the first two decades of the 21st century, the Laboz family leased out the lowest floors as retail space and converted the upper stories to apartments.

Site The Offerman Building is located at 503–513 Fulton Street in the Downtown Brooklyn neighborhood of New York City, New York, U.S. It occupies an irregular land lot on the city block bounded by Fulton Street to the south, Bridge Street to the west, Willoughby Street to the north, and Duffield Street (Abolitionist Place) to the east. The original building has frontage of on Fulton Street and along Duffield Street; including the newer annex, it has an area of . Originally, the building's Duffield Street frontage was only wide. The Fulton Street wing originally extended about deep, but an extension in 1893 increased this depth to .

Due to the unusual shape of the lot, both of the original building's frontages are in the middle of their respective blockfronts. The Offerman Building's site wraps around three buildings at the corner of Fulton and Duffield Streets, which the building's developers had never acquired. Nearby buildings include 388 Bridge Street to the northwest, BellTel Lofts and AVA DoBro to the north, and 1 Hoyt Street and 11 Hoyt to the south. In addition, the entrances to the New York City Subway's Hoyt Street station are next to the building.;

The Offerman Building's site was part of the 19th-century Duffield estate.; The adjacent stretch of Fulton Street, between Brooklyn Borough Hall and Flatbush Avenue, was known as "upper Fulton Street" in the 19th century and was the commercial center of the then-independent city of Brooklyn. After the Brooklyn Bridge opened during the late 19th century, upper Fulton Street contained large numbers of retail stores, which had relocated from the Fulton Ferry landing near the East River shoreline. The opening of the Fulton Street Elevated line in 1888, as well as the opening of the New York City Subway system in the early 20th century, attracted further commercial development in the area. Just before the Offerman Building was erected, the site had been occupied by houses.

Architecture The building was designed by Peter J. Lauritzen in the Romanesque Revival style.; According to the Brooklyn Daily Times, the Romanesque Revival style had been chosen because it "readily lends itself to richness and solidity of design". It ranges between six and eight stories; the section on Fulton Street is generally seven stories high, while the wing on Duffield Street is six stories high. The eight-story tower at the center of the Fulton Street wing was built to a height of . Although the Offerman Building's floor count was not unusual for its time, the ceilings were so high that the structure was one of the tallest buildings in Brooklyn when it opened in 1891.;

Facade On the Fulton Street elevation of the facade, the first and second stories were originally clad with granite, with a light sandstone band above the second story; brick and terracotta are used on the upper stories. The vertical quality of the Fulton Street facade is emphasized by the use of vertical piers, similar to in early skyscrapers. In addition, Lauritzen divided the facade into numerous arcades to give the facade a quality of intricacy. The lowest two stories on Fulton Street have been renovated at least three times: in the 1940s, 1980s, and 2010s. The Duffield Street elevation is similar, except that gray stone is used on the lowest two stories instead.

Fulton Street wing

The facade on Fulton Street is divided vertically into three bays: a central section measuring eight stories tall, which is flanked by a pair of seven-story sections.; There were originally five arches at ground level.; The central section originally was decorated with a three-story arch measuring wide. Each of the outer sections had two display windows measuring high and wide, with transom windows above. Running above the first floor was a cornice which divided the ground and second floors; this cornice was at the same height as the former Fulton Street Elevated. During the 1940s, Morris Lapidus designed a new central arch with a red granite frame and a grid of windows. This arch rises two and a half stories and is surrounded with ornament; above the center arch is a small colonnade with three windows separated by colonnettes. In the outer sections, the first and second stories were redesigned in the 2010s with a cast stone facade, in a simple imitation of the original design, and metal-and-glass storefronts. There are two smaller arches on either side of the central arch at the second story. On the third story, each of the outer sections has four arched windows, supported by colonnettes. There are also lions with the initials "H. O." (standing for Henry Offerman) at either corner.

The windows on the fourth through eighth floors were replaced in 2015. On the fourth to sixth stories, the outer sections of the facade each have two triple-height arches, with two window openings per story. The spandrel panels above the windows on these stories protrude from the facade; this was intended to create the impression of organic quality. Within either of the outer sections, a cornice runs horizontally above the sixth story, and there are four rectangular windows on the seventh story. The center section of the facade has a quadruple-height arch that ascends to the seventh story; the central arch is divided vertically into three windows on each story.; Only the center section rises to the eighth floor, where there are three windows. There are molded Romanesque Revival decorations, such as faces and reliefs, on the sixth through eighth stories above the arches, and there are stone finials atop the eighth floors.;

The side facades of the Fulton Street wing are plain in design. The western facade has window openings and is set back significantly from the wing on Bridge Street. The third through sixth stories each have four windows, while the seventh story has five windows; the rest of the western facade is of plain brick. The eastern facade of the Fulton Street wing was covered by an advertisement until the 2000s. After the 2010s renovation, the eastern facade has had two windows on each of the fourth to sixth stories, while the seventh story has had three windows. There is a wooden water tower above the eastern section of the roof.

Duffield Street wing

The facade on Duffield Street is for the most part six stories tall and ten bays wide. The center eight bays are in two groups of four. All of the windows on Duffield Street date from the 2010s renovation. At the ground story, each bay has an arch supported on large granite piers; the two center arches in each group are taller than the two outer arches. The arches generally feature storefronts that were installed in the 2010s; the southernmost arch serves as the building's residential entrance, which is covered by a glass canopy. The arches originally had large windows that illuminated the back of the ground-level store. There is a deeply recessed window at the extreme northern and southern ends of the Duffield Street facade.

On the second through fifth stories, there are quadruple-height arches supported by shallow pilasters in the eight center bays. There are two windows on the center pilaster: one between the second and third stories, which is rectangular, and one between the third and fourth stories, which is arched. In the four bays immediately to the south of the center pilaster, there is a frieze with the words "1890 Offerman Building 1892" carved above the second floor. There are 23 arched windows on the sixth story, above which is a brick cornice with corbels. At the center of the sixth story is a metal cartouche, which is painted red and bears the overlapping letters "H" and "O".

The northern wall of this wing, measuring wide, has windows that are visible above the roofs of adjacent buildings. The western wall is wide and has eleven rectangular windows on each of the third through sixth floors.; There is a glass-and-metal penthouse above the Duffield Street wing. The southern wall has no windows and is clad in brick.

Bridge Street wing The Bridge Street wing, designed by Greenberg Farrow, was added in 2014 and wraps around the northeastern corner of Bridge and Fulton Street, extending to the Offerman Building's original northern end. The Bridge Street wing is two stories high and has a facade with metal and concrete frame, as well as full-height glass windows. The ground floor contains a storefront with a store entrance, while the second floor is reached through the original building. The structure has a flat roof above the second story.

Interior The original building on Fulton Street had on each floor. The annex on Duffield Street increased the building's total size to approximately per floor or in total. The building's framework may have included both cast-iron and steel columns; the columns were placed in four rows and supported horizontal girders beneath each floor slab. Near the rear left of the building were originally two elevators and a staircase connecting all floors. Following an expansion in 1892, there were seven elevators in total: three freight elevators, one dumbwaiter for packages, and three passenger elevators.