The first two stories, constructed of granite, are vertically divided into five bays; they feature a large central portico with Doric columns.

The predecessor to the Brooklyn Union Gas Company was established in 1825 and built a headquarters at 180 Remsen Street in 1856.

Rapid growth in the early 1900s prompted the company to acquire land in 1912 for an expanded headquarters at 172–178 Remsen Street.

This setback exists because of a restrictive covenant placed by Hezekiah Pierrepont, who owned the site in the 19th century, back when the neighborhood was filled with townhouses.

[4][1] Numerous contractors provided materials for the building as well, including cut-stone supplier John R. Smith's Son Inc. and brick supplier Hay Walker Brick Co.[1] The eight-story facade[8][9] is generally constructed of granite on the lowest two stories and limestone above.

[11] Much of the ornamentation, including spandrel panels with torches and oil lamps, were intended to signify the building's original purpose.

[7][12] On the seventh and eighth floors, the center seven bays are spaced by a series of six engaged Ionic columns rising to an entablature.

The western and eastern walls, which are partially visible from the street, are largely clad in red brick, except at the corners where there are quoins.

[14] When 176 Remsen Street opened, the entrance vestibule led to a corridor leading to the elevators, with two stairways at either end.

Immediately opposite the entrance, through an arch, was the public office, a room with a high ceiling and a central, elliptical-domed skylight.

[8] The public room's counters, column bases, and pilasters were made of polished gray marble, while the walls and ceiling were of Caen stone.

[21][29] The structure was demolished in 2003 and replaced with a 35,000-square-foot (3,300 m2) academic center,[30] which included a three-story library, 14 classrooms, and an auditorium with 95 seats.

[32][33] Brooklyn Union Gas continued to grow after James Jourdan became the firm's president the next year.

"[39] Brooklyn Union Gas planned a larger structure for its business at 172 to 178 Remsen Street,[37][40] and it was selling the old residences' furnishings by that March.

[41] The Eagle reported in October 1912 that the Fuller Company was about to raze the existing buildings at 172 to 178 Remsen Street.

[43] The old headquarters at 180 Remsen Street was converted into Brooklyn Union Gas's Domestic Science Department, which featured a showroom.

[13] The Brooklyn Union Gas Company began exhibiting gas-powered appliances permanently at 180 Remsen Street in 1925.

[10] The building also hosted numerous events and exhibitions during the 1920s and 1930s, including annual Christmas celebrations (a practice which began in 1923),[47] film screenings,[48] cooking classes,[49] and employee flower shows.

[10] During December 1951, the Brooklyn Gas Company leased the third through sixth floors of the neighboring building at 186 Remsen Street, after the seventh and eighth stories of that structure had been demolished.

[55] The college's development director Jarlath Murphy had selected the site so the institution could remain in the "heart of Brooklyn".

[20][56] According to the St. Francis College yearbook from that year, the relocation to 176 and 180 Remsen Street represented "a transformation and the formulation of a new image and purpose".

[63] The AIA Guide to New York City wrote that 180 Remsen Street had been "miraculously saved", but local civic group Brooklyn Heights Association had never formally sought landmark designation for the structure.

[64] Afterward, the campus, including the Brooklyn Union Gas Building, carried the address 180 Remsen Street.

[65] According to the Brooklyn Daily Eagle, there was speculation that St. Francis College officials supported the landmark designation so they could transfer the building's air rights to a nearby site.

[62] The LPC designated the Brooklyn Union Gas Building as a New York City landmark on May 10, 2011, along with the Constance Baker Motley Recreation Center in Midtown Manhattan.

[72] At the end of March 2023, Rockrose Development bought the college's buildings on Remsen Street for approximately $160 million.

[74] Alexico sued the college and Rockrose in July 2023 for breach of contract,[75][76] though the defendants sought to have the suit invalidated.

[77][78] Alexico claimed that, at the time of the sale, it had been reviewing the legal terms of a 19th-century covenant that required the buildings to be set back from the sidewalk.

[5] In October 2024, Rockrose filed plans to convert 180 Remsen Street and two nearby structures into 747 apartments.

[2] In designating the building as a landmark in 2011, LPC chairman Robert Tierney described 176 Remsen Street as "a reminder of a company that literally fueled the growth of a newly expanded City in the first decades of the 20th century".