In Brooklyn, so much attention has been paid to Forest City Ratner Co.’s proposed Atlantic Yards mega-development in Prospect Heights and to the rezoning in Greenpoint and Williamsburg that most people haven’t been giving much thought to the changes in store for downtown Brooklyn. But downtown, such as we’ve known it, will, if the city and developers succeed in their plans, be unrecognizable in a few years.

The Web logs that follow Brooklyn development with intense focus — Gowanus Lounge, Brownstoner, Curbed — buzzed recently with speculation that City Tech Tower, at Jay and Tillary streets, might, judging from renderings that have floated around the Internet, rise between 700 feet and 1,000 feet, which would make the Renzo Piano-designed tower Brooklyn’s tallest building by far. While so many people were concerned about Frank Gehry’s “Miss Brooklyn,” the centerpiece tower of the proposed Atlantic Yards, overtopping the beloved Williamsburgh Savings Bank Building, not so far away the same developer, Bruce Ratner, plans to erect a building that may be twice as high as the borough’s current tallest building.

City Tech is the New York City College of Technology (formerly New York City Technical College), which is part of the City University of New York. The college’s Web site says:

City Tech will soon be home to what is sure to be the architectural landmark of Brooklyn … the most original piece of architecture since the Brooklyn Bridge, a masterpiece conceived by the celebrated architect Renzo Piano.

Those renderings floating around — an old one and a newer one — look a lot alike, and they both look very much like the kind of precision-tooled high-tech modernism we’ve come to expect from Mr. Piano. It may end up a good building — even a great building. But given that Mr. Piano is hardly likely to do anything more for Brooklyn than pull an old design out of a drawer, and given that Brooklyn abounds in buildings better than anything Mr. Piano has ever designed, might not City Tech tone down its self-congratulation just a notch?

There’s recent news also that 44,000 square feet of high-class retail might be carved out of the lower floors of the Brooklyn Municipal Building on Joralemon Street at Court Street. The intersection apparently has as great a weekday pedestrian flow as Sixth Avenue and 23rd Street in Manhattan, yet because several nearby buildings — Borough Hall, Brooklyn Law School, and the Municipal Building — have no storefronts, little retail profit comes of that heavy flow.

At the same time, the Brooklyn Heights Association and the Municipal Art Society have teamed up to identify “historic resources” in downtown Brooklyn preparatory to pushing for landmark designations to protect some of the better old buildings. These are structures that may otherwise be in the path of humongous developments planned for an area that has been rezoned in the hopes that it may compete with Jersey City as an office center. (I provided some research for the report on historic resources.)

All of this makes it a good time to look at some of downtown Brooklyn’s old buildings.

The Brooklyn Municipal Building is rather a staid thing, a squat limestone pile built in 1927. But most of what it’s supposed to do urbanistically it does well, as we might expect from such architects as McKenzie, Voorhees & Gmelin, whose chief designer, Ralph Walker, seldom designed bad buildings and sometimes designed — as we shall see — masterpieces. I especially like the long, 10-columned Tuscan colonnade along Joralemon Street, screening the building’s recessed entryway and sheltering an entrance to the Borough Hall IRT station. In what other station in the city does the beleaguered straphanger get to enter and exit a station through a grand colonnade?

A block to the south, on Court Street at Livingston Street, the 36-story former Brooklyn Chamber of Commerce Building, now a residential conversion, also went up in 1927. Architect A.F. Simberg’s Gothic-detailed, Jazz Age tower rises in tiers as complexly massed as any New York skyscraper of its era, and has lovely terra-cotta accents. Diagonally across Court Street from the Municipal Building, the 13-story Temple Bar Building dates from 1901, when it was the tallest building in Brooklyn. George L. Morse was the architect, and though the building is fussily detailed, it does have some very fine classical ornamentation. Court Street in this section is Skyscraper Row — the compact grouping of tall buildings that one sees handsomely rising above the bluff of Brooklyn Heights across the East River from Lower Manhattan. At the northwest corner of Court and Remsen streets is Schwartz & Gross’s 30-story Court-Remsen Building of 1926, while next door to the south the 40-story Court-Montague Building dates from 1927 and was designed by H. Craig Severance.

Downtown Brooklyn’s most beautiful skyscraper is the former New York Telephone Co. Building at the northeast corner of Willoughby and Bridge streets. Built in 1931, it was designed by Ralph Walker of Voorhees, Gmelin & Walker, as the firm had recently been renamed. It is Walker’s second-best building in the city, after 1 Wall Street. Walker and Ely Jacques Kahn were the two architects who went furthest in exploiting the zoning-mandated skyscraper-setbacks to dramatic advantage. Walker paid fastidious attention to the “skins” of his buildings, with subtle gradations of color and ripplings and folds that outdo any of the skin games played by today’s so-called starchitects. Recently, the office building has been converted to apartments called the BellTel Lofts. City Tech Tower should be half as good.