The master plan for the huge redevelopment of the Con Ed facilities south of the United Nations along the East River by Sheldon H. Solow was filed with the city last week as part of an environmental assessment statement.

Mr. Solow, who has built some of the city?s most distinctive towers such as the sloping 9 West 57th Street office tower and the black-glass apartment tower with curved corners at 245 East 66th Street, plans to erect seven buildings with 2,201 apartments and about 4.2 million square feet of offices on two sites, comprising about 9 acres, that extend from 35th to 36th and from 38th to 41st Streets along First Avenue.

David Childs of Skidmore, Owings & Merrill is designing the commercial structures on the site and Richard Meier is designing three residential towers.

The four towers in the northern site will range in height from 550 to 864 feet and be clustered around a park with a skating rink/toy-boat pond at its center.

An article in today?s The New York Times by Robin Pogrebin quoted Mr. Meier as stating that four towers "would take the United Nations as a starting point, ?then spiral around,?" adding that "Individually, they will be distinct while forming a ?family of buildings.?" One of the tall towers would be on the west side of First Avenue.

The plan is likely to face many hurdles.

Ed Rubin, chairman of the land-use committee of Community Board 4 has expressed concerns about the buildings? height. The United Nations Secretariat Building, one of the city?s most important landmarks, is 505 feet tall and until the erection a few years ago of Trump World Tower it was the tallest structure in the neighborhood. Recently, the Macklowe Organization purchased a site across First Avenue from the United Nations that conceivably could be developed much taller than the United Nations.

More importantly, perhaps, is the future of the Robert Moses playground on the southeast corner of First Avenue at 42nd Street. The United Nations Development Corporation, of which Senator Roy Goodman is president and chief operating officer, has commissioned Fumihiko Maki, the famous Japanese architect, and FXFowle to design an office tower for the site as temporary offices for the United Nations Secretariat while its building undergoes renovations. After the renovations are completed, it would be used as offices for the United Nations.

Mr. Goodman told CityRealty.com today said that the Maki project would be a bit shorter than the Secretariat Building, and would cost less than leasing space elsewhere and be more secure. The building would have about 1 million square feet and have a tunnel beneath 42nd Street to connect with the low-rise United Nations Library Building.

The building would occupy the west section of the Robert Moses Playground, but a dog run and the east section of the playground on the other side of a Queens Midtown Tunnel ventilation structure would remain.

The UN project is understood to also involve the creation of about 100,000 square feet of parks along the river that would compensate the community for the loss of about 30,000 square feet contained in the asphalt playground of the west section of the Robert Moses Playground that would be occupied by the new building.

In the wake of the oil-for-food scandal at the United Nations, the New York State Legislature, however, has held up financing for the Maki project, but Mr. Goodman said he hoped "rationality will prevail."

The Maki tower would partially obstruct some views to the north from the Solow project, but Mr. Goodman emphasized that it would be very contextual with the United Nations enclave.

Another unresolved issue regarding these developments are whether an exit ramp at 42nd Street from the FDR Drive North will be removed, which might influence the final designs of the Maki tower site and the Solow site.