For years, Khalil Gibran International Academy (KGIA)a public school known for offering the first Arabic-English dual-language program in New York Cityhas been sited in a handsome brick school building at the intersection of 3rd Avenue, Schermerhorn Street, and Flatbush Avenue in Downtown Brooklyn. Every day, KGIA students spill out onto a tree-lined triangular plaza overlooking Williamsburgh Savings Bank Tower by Halsey, McCormack & Helmer. KGIAs old building was designed by C. B. J. Snyder, an architect who served as superintendent of New York public schools between 1891 and 1923. During his tenure, Snyder built more than 400 schools in the Beaux Arts, Flemish Renaissance revival, and collegiate gothic styles. The New York Landmarks Conservancy has called Snyder an unsung hero of the city for his efforts.Now, KGIA students and faculty enjoy a new building sandwiched between Flatbush Avenue and State Streetright next to KGIAs old buildingwhich it shares with P.S. 456, or the Elizabeth Jennings School for Bold Explorers. But the design by Architecture Research Office (ARO) isnt far off from the creations Snyder ideated in the century past, albeit with a contemporary twist, and state-of-the-art passive house systems. This is all to say that, in short, the new school by ARO is meant to last.The primary schools pickup and drop-off area is on State Street. (James Ewing/JBSA)They told us, the building had to last 100 years, Stephen Cassell, a principal at ARO, told me one afternoon in November, referring to an early client meeting in 2016 with the New York City School Construction Authority (NYCSCA). We were touring AROs recently completed school building at Alloy Block, together with Adam Yarinsky, a fellow ARO principal. After turning a corner, we noticed that children had taken pink chalk to one of the new buildings exterior walls made of Ironspot brick, with colors that shift in the light, prompting a smile from Cassell and Yarinsky. Seeing kids use the building is really the most rewarding thing, Yarinsky said. We were here a few weeks ago when we met a woman who had just dropped her daughter off. Someone told her that we were the architects, and she unsolicitedly said people are loving the building. Its all been so satisfying.For the KidsYarinsky and Cassell both teach studios at MIT. There, they task students with considering spaces for early childhood education in Boston. ARO has worked on campus projects for some time now, too, including a recently completed hall at University of Washington Tacoma, and an ongoing one for business students at Rice University.ARO is also currently renovating an old bank in Brooklyn Heights that will soon host classrooms for St. Anns, the illustrious school founded by Stanley Bosworth. The Brooklyn offices recently completed school building at Alloy Block was its first for NYCSCA. But it was also the first New York school building that uses passive house principals more broadly. Local Law 31 of 2016, which mandated city-owned capital projects to be built to consume less energy than buildings built under current standards, meant that the playbook had to essentially be rewritten for the school, a challenge ARO responded to with enthusiasm and vigor.The school has a terrace designed by Nelson Byrd Woltz Landscape Architects overlooking Flatbush Avenue. (James Ewing/JBSA)At Alloy Block, the high school (KGIA) and elementary school (P.S. 465) each have dedicated classrooms, libraries, stairwells, and terraces, but share two gymnasiums/auditoriums, and kitchen facilities. The cooking area is sandwiched in between the dining areas, which dont touch. There are also two exterior spaces designed by Nelson Byrd Woltz Landscape Architects: One on the ground floor State Street side, and the other on Flatbush Avenue, one story above the sidewalk level retail space. The lobbies each have bespoke installations by Alfruz Amighi and Wendy Letven, one of which references KGIAs namesake, Khalil Gibran, a Lebanese-American poet. The building they share touches 505 State Street, known as New York Citys first all-electric tower, designed by Alloy, an architecture and development company. Alloy was AROs partner on the school project; it also owns the retail space that spreads into parts of the schools ground floor.A rooftop play area for primary school students is located on the State Street side. (James Ewing/JBSA)The school building and its accompanying tower sit just across from Atlantic Terminal, within walking distance from AROs Downtown Brooklyn office. It impressively uses less than one-third the amount of energy that other New York City school buildings use on average, ARO shared. This will make it the first New York City school building to meet efficiency standards set by Passive Houses Institute US (PHI) when its certification process completes before the year is over. To achieve PHI certification, architects kept super-insulation, airtightness, and heat recovery in mind. All windows are triple-paned, not unlike the recent rehab by Bruner/Cott at Harvard GSDs Gund Hall. Spectacular VernacularInside, the material selection is attractive and economical: The furniture is made of white oak, blue and yellow subway tile lines much of the walls, and the vast stairwells are coated in yellow. The thoughtful interior finishes, matched with Ironspot brick outside, makes the building feel modern and timeless, much like Snyders earlier works all over the city that still stand to this day.Economical materials were selected throughout the school, including blue and yellow subway tiles. (James Ewing/JBSA)The site ARO was given ultimately yielded a thoughtful floorplan, where essentially two volumes meet at a pinch point. Subway lines bustle below grade, necessitating a careful structural grid. Also, a second tower by Alloy will soon go up in the void behind the school, the old Snyder building, and the new all-electric tower. ARO leveraged this floorplate by creating dynamic, angled, corridor spaces that contrast nicely with the typical rectilinear ones from yesteryears that dont perform well for neurodiverse students.Floors four and five host 500 primary school students. Floors six and seven are for 350 high school students. The primary and high schools each have their own vertical circulation infrastructure (stairwells and elevators) to make for ease of passage. For safe pickup and drop-off, the primary schools entry is on State Street, a quiet brownstone-lined road. The high school, meanwhile, is off of Flatbush Avenue, bounded by 3rd and 4th Avenues.State Street and Flatbush Avenue have different energies, so the facades were designed accordingly. The former is serene and has low audio volume; and the latter is typically clogged with traffic, but looks out onto Downtown Brooklyn.A typical high school classroom (James Ewing/JBSA)The dining area for high school students is faced with floor-to-ceiling windows. (James Ewing/JBSA)Repetitive inset windows match the rhythm of the schools neighbors on State Street. Meanwhile, the Flatbush Avenue sides ground plane is lined with glass, and passersby can see into the retail space adjacent to the school building. On the State Street side, the facade shifts in and out just enough to create dynamic shadow lines, offering reliefs. The envelope is made of concrete block back up, a fair amount of insulation, and brick hangers that are longer than normal. These hangers tie the brick to steel, creating deeper windows than your standard new building. Theres a fair amount of detailing that went into the envelope, Cassell said. The windows are actually this subtle green and black hue, something we thought went nicely with the neighboring brownstones.The new schools Ironspot brick was selected to match the context. (James Ewing/JBSA)In the end, these kinds of projects are the most rewarding for us, Yarinsky shared. Its going to be in the city for a long time and theres so much it offers in terms of equity, and supporting very different neighborhoods from all over the city.