THEY had to move a street to build the twin Gothic skyscrapers at 111 and 115 Broadway, fronting on the Trinity Church cemetery. Among the most dramatic office buildings in New York, they are now in their 10th year of a long restoration. But why has the south face remained uncleaned? It has to do with that street.
In 1901 Harry Black established the U. S. Realty and Construction Company, a powerhouse development organization with some of the biggest names in New York real estate, including Robert Dowling, Henry Morgenthau, Cornelius Vanderbilt and Charles F. Hoffman.
By 1902, corporations were replacing individual developers in building expensive skyscrapers, and U. S. Realty had $66 million in working capital -- about $1.9 billion in today's money. For its first large project, it bought the old Trinity Building, an office building at 111 Broadway with a 258-foot south frontage over the Trinity Church cemetery. In a period before zoning regulation and efficient indoor lighting, the natural-light potential of a site was important in renting offices.
The old Trinity Building was long and narrow, sandwiched between Trinity cemetery on the south and tiny Thames Street on the north -- it had only 40 feet of frontage on Broadway. U. S. Realty's earliest plan was to combine the Trinity site with land on the north side of Thames, and then relocate the street along the edge of Trinity cemetery. But acquisition delays held that project up, and U. S. Realty went ahead with a 21-story building on the site of the Trinity Building itself, 40 feet wide and 290 feet high.
The English-trained architect Francis H. Kimball designed the new Trinity Building in the neo-Gothic style, which was not yet accepted as a solution for skyscraper design. In 1903 Kimball told The New York Times he wouldn't use a white stone like marble, because it would be ''almost blinding.'' But revisions in 1904 called for limestone as well as another important change: The north wall of the Trinity Building was to be left in utilitarian brick, so that it could be expanded -- Thames Street would be relocated to the north, not to the south.
Furthermore, U. S. Realty was angling to buy enough property to erect a nearly matching building on the north side of the relocated street. All the offices in the two narrow buildings would be outside rooms -- the earlier design for a single larger building would have required light courts -- spaces for light and air -- which were expensive and also, by some accounts, ugly.
The new 21-story Trinity Building was 95 percent rented by May 1905, when it opened for tenants like Diamond Match and Westinghouse. Published plans show large common rooms at each end, with a corridor and elevators along the north wall and individual rooms along the south wall, facing the cemetery.
By this time U. S. Realty had gained possession of plots on the north side of Thames Street and, with city permission, it cleared the land, moved Thames Street 28 feet north, and simultaneously began extending the Trinity Building and erecting the new U. S. Realty Building, numbered 115 Broadway, completed in 1907.
The 1905 Trinity Building measured 166,000 square feet; the new, twin buildings were a total of 553,000 square feet, with an average annual rental of $3 a per square foot for Trinity and $2.75 a square foot for the U. S. Realty Building, which had northerly windows on Cedar Street but lacked the cemetery view.
The completed 111 and 115 Broadway must have been amazing to New York, where, outside of ecclesiastical design, the Gothic was an exotic species. They rise straight up from their narrow plots, covered with gargoyles, moldings and other details. Although they are a close match, Kimball prevented a pure twin effect by giving the Trinity Building a five-story cupola at the top.
The interiors are spectacular -- long, highly decorated corridors with extensive bronze work and polychrome ceiling painting. These, along with some store window details, were restored in a campaign begun in 1987 by Swanke Hayden Connell Architects. Examine the ''original'' entry screen at the U. S. Realty Building -- only close inspection shows it's a completely modern work, a masterful counterfeit.
IN 1907, the Lawyers Club took two floors at the top of the U. S. Realty Building, custom-fitting the space for its own purposes -- it included a double-height dining hall on the Broadway end with a gigantic stained-glass window. Standing in this room, with sunlight pouring in through banks of windows fairly close along each side, is almost like riding in the gondola of a blimp.
Now the two buildings are recovering from several years of foreclosure and vacancy. William G. Cohen, executive vice president of Newmark & Company, says his firm has been the exclusive leasing agent for the buildings since 1990, when the Trinity Building was partly occupied and the U. S. Realty Building was ''essentially empty.'' He and a group of Newmark executives bought the buildings in 1994 and sold them last December to I. T. W. Mortgage Investments III, a subsidiary of the Illinois Tool Works.
Mr. Cohen has worked to bring the occupancy rates in the buildings above 90 percent; Newmark signed 48 deals for space in both buildings last year. Good electrical supply and a large investment in prebuilt space, he said, has proved attractive to start-up financial and computer companies, which pay in the $25 a square foot range. One of the newest leases is to Transaction Information Systems, a computer company, which has taken over the abused but mostly intact space of the Lawyers' Club.
Mr. Cohen says Newmark has spent $5.5 million on infrastructure in the two buildings since 1990, including the current repair of the cupola at the top of the Trinity Building, damaged in a fire two years ago. Another project is the cleaning of the south facade, left untouched in the restoration campaign of the 1980's. At that time all facades except the cemetery one were cleaned, although that work was not supervised by the Swanke Hayden firm.
An architect and a real estate executive familiar with that project who spoke on condition of anonymity said the 1980's cleaning used acid and water, which damaged monuments and plantings in Trinity Church's graveyard. Wilfred Sherk, Trinity Church's chief financial officer, said there had been damage to the Soldier's Memorial Monument in the graveyard that cost about $50,000 to repair. Mr. Sherk said the church was asking to see any future cleaning specifications and for insurance protection.
Mr. Cohen and Robert Cum, the property manager, say that Newmark would like to clean the south facade, using only distilled water and an extensive protection system. They have the money budgeted, but are delayed by the logistics -- including getting Trinity Church's approval. If Thames Street had been moved south, instead of north, they could have done it long ago.
Photos: Trinity and U.S. Realty buildings in 1912. (Museum of the City of New York); The original Trinity building, in 1905. (Office for Metropolitan History); Newmark, current owner, has plans to clean south facade. (Philip Greenberg for The New York Times) Map of New York City showing the location of Battery Park City.