Developers seeking an air rights transfer on St. Marks Place to build a 10-story office complex failed to gain a key supporter to push their project forward on Wednesday.

City Councilmember Carlina Rivera officially came out against an air rights transfer that developers want in order to build a 10-story office complex at St. Marks Place and Third Avenue in the East Village.

Used by developers as a way to build denser structures, air rights transfers allow landmarked buildings to sell undeveloped square footage to a nearby lot, in part to raise money for the upkeep of historic buildings.

The developers, Real Estate Equities Corporation [REEC], applied for the air rights transfer from the landmarked Hamilton-Holly House at 4 St. Marks Place to a property across the street, at 3 St. Marks Place. The Landmarks Preservation Commission has already approved the air rights transfer, and the request is currently winding through the city's public review process, which ends with a City Council vote where Rivera holds a pivotal role as the local councilmember.

"St. Marks Place holds a very special place in our community," Rivera told Gothamist. "Many people call it the 'Gateway to the East Village.'"

"In this case, the permit the developer is applying for and the additional air rights they're requesting and [the building's] relationship to the surrounding streetscape and the landmark—they were troubling to me given the stipulations of the permit," Rivera said, referring to the specific zoning provision 74-79. "I know I need to come out and recommend that [the City Planning Commission] vote to reject this."

The air rights transfer would allow for developers to build by 8,386 square feet larger, to 10-stories tall—about 20 percent larger than what the developers could build without special approvals, or as-of-right.

REEC plans to pay the owners of the landmarked building, where Alexander Hamilton's son once lived, $4 million for the development rights. Five percent of that, or about $200,000, would be dedicated for future maintenance of the landmark. The company has previously said it has already contributed about half-a-million dollars towards restoration.

At Wednesday's public hearing, the project's architect Morris Adjmi emphasized a building of a similar height size could be built as-of-right, saying, "one could build this building without a special permit, without transferring any air rights, and it is 22 feet taller at the street wall and also more or less the same height overall."

Architect Morris Adjmi shows different options for the building at 3 St. Marks Place. The center is as-of-right.

A rep for the developers, Adam Taubman of the law firm Kramer Levin, also said at the hearing the currently vacant lot would see construction whether or not the permit is approved.

Rivera maintained her position that the proposal doesn't meet stipulations under 74-79 for more than 8,300-square-feet of additional development rights.

"We were very clear in that we did not find enough community support and given the stipulations of the permit, we just told [the developers] that we didn't really see a way forward," Rivera said. She added: "As it stands today, [the landmark] is already in excellent condition with significant repairs made in very recent years."

The Greenwich Village Society for Historic Preservation has been fighting the project for months—seeing the development as an extension of rising office developments in the East Village, such as the under-construction 21-story "Tech Hub" on 14th Street (which Rivera supported).

"We have said from the beginning that this proposal to increase the size of the planned tech office tower at the "gateway to the East Village" is wrong, and would only serve to accelerate the spread of ‘Midtown South’ and Silicon Alley to this neighborhood," Andrew Berman, the group's executive director, wrote in an email. "With Councilmember Rivera’s stated opposition today, we are optimistic that the air rights transfer can and will be defeated."

Rivera submitted joint testimony with Assemblymember Deborah Glick and State Senator Brad Hoylman, who have previously expressed opposition, urging the commission to deny the application. They called the development "out of context" with the landmark as well as "the surrounding streetscape and character" in written testimony.

The City Planning Commission will hold a vote at a future meeting after deliberating on testimony from a public hearing Wednesday. REEC did not immediately respond to a request for comment on Rivera's opposition.

This article has been updated to clarify how air rights transfers work.