Mr. Rangel, the powerful Democrat who is chairman of the House Ways and Means Committee, uses his fourth apartment, six floors below, as a campaign office, despite state and city regulations that require rent-stabilized apartments to be used as a primary residence.

Mr. Rangel, who has a net worth of $566,000 to $1.2 million, according to Congressional disclosure records, paid a total rent of $3,894 monthly in 2007 for the four apartments at Lenox Terrace, a 1,700-unit luxury development of six towers, with doormen, that is described in real estate publications as Harlem’s most prestigious address.

The current market-rate rent for similar apartments in Mr. Rangel’s building would total $7,465 to $8,125 a month, according to the Web site of the owner, the Olnick Organization.

The Olnick Organization and other real estate firms have been accused of overzealous tactics as they move to evict tenants from their rent-stabilized apartments and convert the units into market-rate housing.

Tensions are especially inflamed in Harlem, where the rising cost of living and the arrival of more moneyed residents have triggered anxiety over the future of the historically black neighborhood. And Vantage Properties, a company established by Olnick’s former chief operating officer, has attracted billions in private equity financing by promising investors that it can aggressively convert tens of thousands of rent-stabilized apartments, many in Harlem.

Yet Mr. Rangel, a critic of other landlords’ callousness, has been uncharacteristically reticent about Olnick’s actions.

State officials and city housing experts said in interviews that while the law does not bar tenants from having more than one rent-stabilized apartment, they knew of no one else with four of them.

. . .

Mr. Rangel, 78, declined to answer questions during a telephone interview, saying that his housing was a private matter that did not affect his representation of his constituents.

“Why should I help you embarrass me?” he said, before abruptly hanging up.

And now, board member Dick Zigun is showing his ingratitude by planning to resign from the agency overseeing Coney Island development to protest the administration’s revamped vision for the fabled amusement district.

Zigun confessed Friday that he’s lived for the past decade on the second floor of the majestic Surf Avenue building that also houses a nonprofit organization he founded in 1980.

Zigun’s Coney Island USA — which runs a world-famous circus sideshow and museum and organizes the annual Mermaid Parade — had been paying $100,000-a-year rent on the site until 2007, when the city handed it $3.6 million in taxpayer-funded grant money to buy the building from its previous owner as part of an expansion plan.

But Zigun’s secondary use of 1208 Surf Ave. as his home appears to be a blatant violation of the funding agreement with the city.

In 2004, the city’s Educational Construction Fund — an agency controlled by the mayor — leased the land to the DeMatteis Organization and the Mattone Group.

The luxury condo building going up at the site will also include the new, 520-seat Middle School 114. The developers will pay for both the $40 million school and the $103 million apartment building.

. . .

Not so, Mr. Miller and his staff recently discovered: New York’s land area actually totals 304.8 square miles.

The shrinkage generally is not the result of rising sea levels from global warming or beach erosion or any other act of nature. It is largely the work of man, mainly Mayor Michael R. Bloomberg, whose yen to precisely measure everything from poverty to traffic congestion led the planning department to recalculate the city’s land mass.

Acting on the mayor’s mandate, Mr. Miller and his team spent months analyzing thousands of digitized, high-resolution aerial photographs of the squiggling shoreline and other geographic features to calculate the city’s size anew.

“This is not a reflection of a change in the physical area, but a refinement of the measurement,” Mr. Miller said.

Seventeen square miles may not seem like much. But consider:

• 17 square miles could accommodate 13 more Central Parks, nearly a third of Washington, D.C., about three dozen versions of Vatican City and nearly two dozen replicas of Monaco.
• If 17 square miles were populated at Manhattan’s density, New York might be home to as many as 1.1 million more people.
• At the price of an acre in Midtown, as recently computed by the Federal Reserve Bank of New York, 17 square miles could be worth $1 trillion.