NoLiTa Place at 199 Bowery, a luxury rental building, is next to the Andrews Hotel, where a 5-by-7-foot sleeping cubicle costs $9 a night.

Zella Jones at the site of a dormitory with 174 studio apartments that is to be leased by New York University.

Rosanne Haggerty, director of Common Ground, and Tony Matarano, a resident of the Andrews Hotel. An addition has risen over 259 Bowery.

Rent for the penthouse in a renovated building across the street and down the block at 214 Bowery: $5,500 a month.

The Bowery is gentrifying.

And as the six-lane, median-stripped, 19-block-long roadway that once meandered past Peter Stuyvesant's 17th-century farmhouse faces another of its transformations, a host of tensions and juxtapositions have come vividly into play.

There is the squeeze between low-income and luxury housing with its corollary clash of social class. There is the prospect of increased population density as high-rise residential buildings, college dormitories and office towers replace swaths of three- and four-story — and sometimes historically storied — tenements, row houses, night-by-night flophouses and saloons with sordid pasts.

At stake also is the fate of a phalanx of storefront businesses that constitute a viable segment of the city's already fading manufacturing sector: lighting, restaurant and refrigeration equipment suppliers facing rent pressures and very inviting buyout offers.

Woven through those hard-cash questions are deeper policy debates concerning what some community activists contend is lot-by-lot development that lacks cohesion and endangers the architectural and historic character of the neighborhood while, at the same time, not taking into account future pressures on an increasingly vital downtown thoroughfare.

And then there is the question of where residents of that dwindling supply of ramshackle, so-called temporary lodging houses — some of whom have lived in the same cubicle for half a century — are to go.

Peering for long periods out of a second-floor window in the dimly lighted day room at the Andrews Hotel, 73-year-old David Riley says he isn't worried by shifting trends in the street below. Mr. Riley, a plumber from Harrisburg, Pa., has lived on the Bowery since 1948. He has seen a lot.

"Used to be bums lying everywhere," he said. "There was the Third Avenue el; you could ride all night long and nobody bothered you. There was a penny arcade; you could get tattoos for a quarter." He rolled up his sleeves to prolifically illustrate his point.

But Mr. Riley said he "never liked this street; too many muggers." So, of the transformation, he said: "It don't bother me. I've been here too long to worry about change." Yet next door to the Andrews, at 199 Bowery, construction elevators climb daily to the top of a sparkling new 12-story luxury rental building, developed by the Washington-based Carlyle Group.

To be called NoLIta Place, the 24-hour doorman building will have 65 studio, one-bedroom and two-bedroom apartments with 19,000 square feet of first-floor retail space. "We think it's a great opportunity for people from downtown and midtown to live in the SoHo-NoLIta market," said Al Troup, the vice president of the Carlyle Group, whose president is Frank C. Carlucci, a former secretary of defense, with former Secretary of State James A. Baker III serving as a partner. (NoLIta is short for North of Little Italy.)

"We think the Bowery is an up and coming neighborhood," said Mr. Troup, who declined to disclose the rent range for the new building, though the rental office opens next month.

Tom Bianca knows how stratospheric rents can become on the Bowery, which runs from Chatham Square north to Ninth Street. Mr. Bianca is a real estate broker and a partner in the AHJ Corporation, a development company that recently purchased the Prince Hotel at 218 Bowery.

"They just renovated the whole building next to ours," Mr. Bianca said. "The penthouse is 2,400 square feet, a duplex; they just got $5,500 rent a month. The one underneath is 2,000 square feet; they got $4,500." Down the block, a two-story building recently sold for $3.5 million, he said.

Obviously, Mr. Bianca's company has plans for the old Prince Hotel, for which it paid $2.2 million in December 2000 — "a really good deal," he said — even though, at the time, 53 of the building's 195 cubicles still housed elderly lodgers.

"Between attrition and buying some out, we're down to 26," Mr. Bianca said. "When we came in, we let everybody know that, obviously, they are protected by the hotel stabilization laws. We knew that. These people shouldn't be thrown into the streets. We told them that if they want better accommodations we would assist them with money."

Eventually, the company hopes to create luxury lofts at the Prince. "It's 50 by 100 feet, four stories; that's 20,000 square feet," he said. "We can build an additional 12,000 square feet on top of the building."

Mr. Bianca estimates that his company can create eight or nine 3,000-square-foot condos in the building. "If we were selling now, it would be $500 per square foot; so that's $1.5 million per unit," he said. "Gross, anywhere from $12 million to $15 million."

"Whodathunk?" Mr. Bianca said.

There was a time when block after block of the Bowery was dotted by bars, brothels, vaudeville houses, gospel missions, pawn shops, day-labor agencies and "slop joints" advertising their stews and sandwiches on sidewalk chalkboards. And, of course, there were the flophouses — a generic term that came to cover everything from loftlike spaces where down-and-outers could throw down a coat or a newspaper and flop down for the night, saloons that ran a rope from wall to wall for unstable clientele to slump over till dawn, and cubicle hotels — up to 75 of such establishments by the turn of the last century.

NOW there are nine lodging houses (a more refined term) left, bearing such ironic names as the Palace, the Prince, the Grand, the Sun and the Providence — the latter three in Chinatown, serving an Asian immigrant population with double bunks in cubicles occupied in eight-hour shifts.

"It was home to the world's most infamous skid row for decades," said David Isay, who, along with Stacy Abramson and the photographer Harvey Wang, produced a book, "Flophouse: Life on the Bowery" (Random House, 2000), documenting the last vestiges of those harsher times.

"Starting in the early 19th century, it was a low-rent Broadway with dime museums, freak shows, burlesque," Mr. Isay said. "After the Civil War, with soldiers coming back and no place to go, it became even more low class and mostly male."

By the 1880's, in the shadow of the new Third Avenue el, the Bowery was widely derogated as a skid row — a term appropriated from Seattle where day laborers would skid logs down a hill to ships at the docks.

"There were some interesting characters associated with the Bowery," said Paul Parkhill, co-director of Place in History, a group that sponsors history exhibits.

"There was Steve Brodie, who hit the front page of every newspaper on July 23, 1886, after he claimed to have jumped off the Brooklyn Bridge," Mr. Parkhill said. Brodie owned a saloon at 114 Bowery. And, after his stunt, he was asked to join the cast of a play called "On the Bowery."

Brodie sang a song that local merchants would later claim wrought great damage to the street. One lyric said he "had one of the Devil's own nights" on the Bowery. And the chorus reprised: "The Bowery, the Bowery! I'll never go there any more."

But Brodie cannot bear all the blame. "There was Chuck Connors, the so-called mayor of Chinatown," said Mr. Parkhill, "who would stage walking tours in which he would set up bogus opium dens and bring middle-class New Yorkers to witness the depravity of the Bowery."

Mr. Parkhill's group has preserved, as a traveling street exhibit, one of the cubicles from the Palace Hotel at 313 Bowery. Called the Bowery Hall of Fame, the cubicle's walls are lined with historic citations from the street's meaner times.

The New York City Department of Housing Preservation and Development sees finer times for a 2.75-acre tract at the heart of the neighborhood, where the Bowery intersects with Houston Street.

The nearly vacant land — between Second Avenue and the Bowery, Second Street to the north and Stanton Street, one block south of Houston — was once dense with low-rise 19th-century buildings. And it was officially cited as blighted in the late 1950's, during the Robert Moses era of scythelike slum clearance.

"This was the classic urban renewal story," Mr. Parkhill said. "Slum clearance became a dirty word. It got bogged down in the changing planning philosophy; the historic preservation movement started to take hold." And so, after the site was designated as the Cooper Square Urban Renewal Area in 1970, Mr. Parkhill said, "It sat partially vacant for 30 years."

Six years ago, however, a deputy mayor, Fran Reiter, brought together H.P.D. officials, community leaders and local politicians to form the Cooper Square Task Force. "There was a three-year effort, a dozen public meetings," said James F. Lima, the assistant commissioner of H.P.D. "We wanted a consensus before going through the difficult process of public approval. And it quickly coalesced around a predominantly residential program."

Eventually, the plan called for the construction of 712 rental apartments — 75 percent market-rate, 25 percent low-income — in buildings of no more than seven stories north of Houston Street and up to 14 stories south of Houston. The area will include 150,000 square feet of commercial space. Chrystie Venture Partners has been selected to develop the $230 million project.

"There will also be a public recreation center with a gym and a swimming pool, built at the developer's expense," Mr. Lima said. Assuming construction starts by the end of this year, he said, "we're talking about five years to completion."

Despite the task force's consensus, the plan has opponents. Kate Millett, the author and feminist activist, has lived at 295 Bowery for nearly 30 years. The building, slated for demolition as part of the urban renewal plan, includes McGurk's Suicide Hall — so dubbed after 1899 when two prostitutes, Blonde Madge and Big Mame, decided to end it all by drinking carbolic acid.

The saloon, Ms. Millett wrote in 1999, "has stubbornly remained notorious for a hundred years, a landmark of gossip and legend repeated in every nook about the City of New York."

"If McGurk's is turned to dust and supplanted with blank high-rise market housing," Ms. Millett said, "official power will have buried its past."

Cooper Union, the science and arts college located where the Bowery becomes Fourth Avenue, plans a shift of its recent past. Two weeks ago, the City Planning Commission certified the start of Cooper Union's application process to tear down its 1950's School of Engineering, rebuild it nearby and replace it with a 17-story office building.

The entire block where the engineering school now stands — bounded by 9th and 10th Streets, Third and Fourth Avenues — would be cleared. A Cooper Union statement this week called the site "a prime commercial location in a relatively high-density commercial and residential corridor."

The college's vice president for business affairs, Robert Hawks, said: "We're anticipating construction of about 400,000 square feet of office space, although with some community facilities. We're hoping to break ground by the end of 2003." No developer has been selected. A new engineering building is to be constructed at Third Avenue and Sixth Street.

And the building goes on.

At the intersection of the Bowery and Second Street, Coral Realty is constructing a $30 million, 13-story dormitory with 174 studio apartments for lease by New York University.

All along the Bowery, old buildings are being renovated. "Some of them are owner-occupied," said Mr. Bianca, the Prince Hotel developer. "A lot of these people have owned these buildings for decades, bought them for $50,000 in the 50's, 60's." In some instances, duplex penthouses have been erected on top of old buildings.

Harold Mazer, 79, has owned Mazer Kitchen Equipment at 207 Bowery, since 1946. "When I came down here, it was bar, flophouse, bar, flophouse, bar, barber school — they used to use the unfortunates for training," he said.

"Next to us is a lighting place," Mr. Mazer continued. "They've got a `For Sale' sign up. Next to that somebody tore the entire inside out of the building. He has two sons who are artists; they're going to live there, have their studios there."

Within a decade, Mr. Mazer predicts, the entire neighborhood will be changed. "They're looking to sell to young, affluent couples, lawyers that come from across the country," he said. "They'll stay two, three years, then move uptown."

Eventually, Mr. Mazer believes, businesses like his will disappear. "They're not going to allow this greasy, dirty stuff on the sidewalk; the spraying of used, dirty equipment outside," he said. "I feel, 5, 10 years, remember what you're looking at."

The Bowery is the dividing line between Community Boards 2, to the west, and 3, to the east. "There are all kinds of developers buying up lots," said Arthur Strickler, the district manager of Community Board 2. "There are more clubs, bars, restaurants. We get applications for liquor licenses like crazy now."

Mr. Strickler mentioned an application for the site of the old Bowery Savings Bank, near Canal Street. "The application is for a catering license," he said, "but put the word catering in quotation marks because, in essence, it will become a disco."

"I can't say whether all this is good or bad," he continued, "But it's the ebb and flow of the city since time immemorial. The Dutch pushed out the native population; the English pushed out the Dutch; and it's been like this ever since."

Zella Jones, the chairwoman of the NoHo Neighborhood Association, hardly longs for the bad old days on the Bowery. "While some people wax nostalgic about the flophouses, the bordellos," she said, "the fact is that for the last 40 years, at least, the Bowery has been a very cruel environment. I'm not upset with its development."

What troubles Ms. Jones is a lack of coordination. "There is no oversight — not on purpose," she said. "The boards are overwhelmed by applications, and one board looks at one side of the street, the other at the other side."

"It's a free-for-all," Ms. Jones said. "Applications are filed for just the block and lot being developed, and no attention is being paid to their symbiosis."

THE historic character of the Bowery, she said, "stands in danger of being obliterated by false facades, cropped cornices, additions to the heights of buildings that are structurally or aesthetically unsound." Officials at the New York City Planning Department declined to comment.

Mr. Strickler of Community Board 2 agrees, at least in part, with Ms. Jones: "People want it to have some cohesiveness, rather than hodgepodge. A lot of very old buildings on the street, they should be protected before they are all knocked down."

Back at the old Andrews Hotel, Roseanne Haggerty believes there remains something deserving of protection — the men who have been there for decades and newcomers seeking refuge, even on a very changed Bowery.

Ms. Haggerty, director of Common Ground, a nonprofit group that helps the homeless, hopes to bring a shine to the dingy, narrow, six-story building where 90 of the 200 cubicles — with their dangling light bulbs and chicken-wire ceilings — are still occupied.

In January, Common Ground bought the Andrews from the family that had owned it for 50 years. The $7 million needed to acquire and renovate it came from the New York State Homeless Housing Assistance Program, the city's Department of Homeless Services, the John Merck Fund, the New York Foundation, Deutsche Bank and the Greenpoint Savings Bank.

"The principle behind this project is that there is a missing tier of housing that used to be filled by the lodging house," Ms. Haggerty said. "The loss of these cubicle hotels contributed substantially to increased homelessness."

A breakthrough for Ms. Haggerty, she said, "was realizing that the typical squalor of these buildings was a management problem, not a problem of concept or design." And that the ingredients for a successful lodging house are renovation, committed on-site management and the matching of residents with needed services.

After the renovation, the 90 existing residents will have the right to stay permanently, paying $36 a week. New tenants may stay for up to 21 days, at $7 a night.

The project is called First Step; its intention is to give tenants assistance toward moving to the next level of housing. On site will be housing-placement workers and counselors capable of linking residents with drug, medical and mental health services.

To accommodate existing tenants, renovation work will be done in two phases with the entire job taking about 15 months. The plan calls for reducing the cubicles from 200 to 150, allowing them to be enlarged to 8 by 6 1/2 feet.

"We're excited about making it architecturally interesting," Ms. Haggerty said, "different styles of units, flat roofs, peaked roofs, different materials, different colors; so it won't seem grim, institutional." Each cubicle will have a bed, a desk, a chair and lockable clothing storage.

Currently at the Andrews, there is one bathroom for every floor; when the work is done, there will be one bathroom for every five cubicles.

Mr. Riley, the resident since 1948, already sees a difference. "We have doors on the bathrooms now; never had that before," he said. "These people do everything we need. They give me attention."