Two-bedroom condos at the Belnord start at just over $3 million and three-bedrooms will range from about $4.4 million to $7.3 million, according to preliminary documents filed with the state attorney general’s office. The most expensive unit, with seven bedrooms and 5,093 square feet, is $18.4 million, the filings show.

The Belnord, with a 22,000-square-foot (2,040-square-meter) landscaped courtyard at the center of its fortress-like walls, is special enough that “there is no competition for us,” Feldman said. “Nobody’s replicating the Belnord. They can’t afford to replicate the Belnord.”

Feldman likes the building so much he bought it twice -- first in 1994, for $15 million, with partners Gary Barnett of Extell Development Co., and Kevin Maloney of Property Markets Group. The trio managed and refurbished the Belnord as rentals, with Feldman eventually selling his stake. In 2015, he paid $555 million to make the property his.

‘Botox Treatment’

Stern’s plans, which have been approved by the city’s Landmarks Preservation Commission, amount to a “very high-class Botox treatment” for the building, the architect said. He’ll reconfigure the apartment layouts, adjust the courtyard’s circular driveways so cars of today can pass each other, and include modern amenities such as a fitness center and central air conditioning. Plans also call for adding some duplex penthouses on one side of the property, where the upper levels lead out onto a terrace.

“It is a uniquely New York kind of apartment house -- like a palace,” Stern said. “It’s got great bones.”

HFZ eventually plans to renovate the entire 213-unit Belnord into condos as the remaining apartments, now occupied by renters, become vacant over time, Feldman said. In its filings, HFZ estimated a full-building sellout at $1.35 billion, which would be among the highest ever on the Upper West Side.

Pushing Boundaries

That’s pushing boundaries for a property that’s only 14 stories high, and too far west to offer unobstructed views of Central Park from even its top-most floors, said Jonathan Miller, president of appraiser Miller Samuel Inc. Manhattan’s loftiest prices are usually reserved for upper-level apartments in the tallest towers, he said.

“Buildings that are over 50 stories in a neighborhood, that’s what skews the luxury price per square foot, because the views are what they’ve been selling,” Miller said.