Riverside Center South, a project of Extell Development Co., is the planned residential and commercial community that is slated to begin construction this year on a 77-acre site along the Hudson River between West 59th and 72nd streets.

When Extell came to the Community Board in 2010 with initial plans, a move triggered by the Uniform Land Use Review Process, the community demanded several changes. One of the most important was that the company build a new school to accommodate the influx of children, which Extell agreed to. The other community concern, a need for affordable housing, will now become a reality as the development of Building 2 gets under way this fall.

“The way that the deal kind of got struck [initially] was they were offering a certain amount [of affordable housing] that would last only 20 years,” said Mark Diller, chair of Community Board 7. “We wanted more than that—we wanted a portion of it to be on site and we wanted it to be permanent.”

The Dermot Co. has purchased the building rights for Building 2 (which will be at 15 West End Ave., at the corner of West 61st Street) from a joint venture between Extell and the Carlyle Group, and has agreed to an “80/20” market-rate to affordable housing ratio, a move that gets the company a better financing rate. The victory, however, comes from the fact that the company will be building the full 20 percent requirement on the site, instead of putting some of the units off-site, which often happens—legally—with large development projects.

The board resolution approved of the Dermot Company’s plan to make 127 of the 616 units in Building 2 affordable housing units, which will be available to individuals earning $23,000 a year or a family of up to four earning $43,000 (figures that represent 50 percent of the Area Median Income). The company also agreed to certain stipulations about how those units would situated in the building—for example, they cannot all be clustered on one or two floors and must contain the same percentage of studio, one-, two- and three-bedroom units as the market-rate units.

Some board members expressed concern that the development leaves out moderate-income housing, which is also in demand in the neighborhood.

“Yes I’m voting for this, I’m very grateful for all the points, but I just want to make it clear that the developer is getting a better rate of interest because these units will be available to what I would call poor people as opposed to moderate-income people,” said board member Helen Rosenthal.

A few others expressed an entirely different concern. Page Cowley, an architect and the co-chair of the Land Use committee, said that she was casting a negative vote not because she disapproves of the affordable housing, but because she disapproves of the building’s new design.

“This community board and subcommittee spent about two and a half years watching the master plan for this amazing parcel grow, and all the sudden … it is being sold on to a developer who is building a differently shaped building,” Cowley said. “It seems petty, but when you looked at the original proposal, it was of a very unique character.”

The original renderings that the board approved during the ULURP process were designed by Christian de Portzamparc, a Pritzker Prize-winning architect.

“We spend a lot of time on the Upper West Side looking at quality of life issues and the way that we look at our buildings,” Cowley said, noting that she would be writing a minority report to include with the board’s official approval. “If we’re worried about flowerboxes on a rowhouse, I don’t understand how this development could not go though another review of how they’re going to divide the parcels up and look so different.”

Borough President Scott Stringer rejected Extell Development’s plans for the Riverside Center development Aug. 31.

The proposed five-building, 3-million-square-foot development would create too much burden on the Upper West Side, the borough president’s report concludes. Stringer likened it to the Riverside South plan, which laid out the blueprints for the redevelopment of the land between West 59th Street and West 72nd Street, from West End Avenue to the river. Riverside Center is the last undeveloped parcel of land in Riverside South.

“The Riverside Center development has the potential to either improve the neighborhood or to recreate the past mistakes of Riverside South,” Stringer said in a statement. “This is not about no development—it’s about appropriate and responsible development.”

Stringer’s stance on land use matters like this is advisory. The project’s next stop in the public review project is the City Planning Commission. If approved there, the City Council has the final and binding vote on the project. Council Member Gale Brewer has generally been in favor of the Community Board 7’s recommendations.

Stringer’s conditional disapproval and recommendations were based on many of the same issues Community Board 7 raised when it considered the proposal.

On building a new school, Extell, the developer, was to fund 75,000 square feet of space and build an additional 75,000 square feet should the School Construction Authority provide funding. But Stringer’s report states that the bad economy makes additional funding unlikely and Extell should construct the full 150,000-square-foot school.

The report also criticizes the open space component of the project. Much of the open space is on private streets and in the middle of the development. Even in the central open space, the report says, the southern buildings will cast a shadow and block air and light. Building the development at grade rather than at street level, the report says, hampers access to open space.

“[Extell] must produce a site plan that results in a better relationship among buildings and open space to public streets,” the report recommends.

As for the details around automobiles in the development, the report asks Extell to limit parking to one floor at 1,100 spaces, nix the car service center and reconsider the automobile showroom, characterized as a “destination use that does not serve a local need.”

The affordable housing component has also changed. During the borough president’s review process, Extell agreed to make 20 percent of residential space permanent affordable housing.

“I encourage Extell to continue working with the City Planning Commission and the Council to reach a satisfactory resolution that addresses community concerns,” Stringer said in a statement.

Extell spokesperson George Arzt gave this statement on the borough president’s decision:

We are disappointed that the recommendations by Borough President Stringer do not adequately recognize these continuing difficult economic times. The proposed reduction in density, along with the borough president’s other recommendations, threaten the economic viability of riverside center. This project will bring important and significant benefits to the city and the community, create tens of thousands of construction and permanent jobs and generate new tax revenues for the city and state. We will continue to discuss the project with the borough president as  [the public review process] proceeds and are hopeful we are able to receive his support.

Riverside Center Stringer