Six years ago, when Kallie Benes and her husband were looking for a home to buy, Shady Acres was a jumble of well-kept bungalows and faltering wood-frame houses, "sketchy" apartment complexes and smatterings of new construction.

Trailer parks and halfway houses dotted the streets in a place named for the shade trees that once grew abundant on one-acre lots. Elderly residents, who came up in the days when an oil pipeline divided the black side of the working-class community from the white, still occupied many of the small, single-family homes.

But it felt safe, it was close to downtown and - most importantly - it was within reach for young professionals who couldn't afford the upscale townhomes and pricey cottages of the nearby Heights.

Benes, director of youth services at the Houston Public Library, and her husband, who works for J.P. Morgan, liked the "eclectic vibe" and sensed potential. So they made offers on three houses. The first fell through. The second descended into a bidding war - a harbinger, Benes realizes in retrospect, of things to come.

The third - a two-story, brick townhome with a tiny patch of grass, and more room for less money than they would have paid in the central Heights - became theirs.

Today, the house is decorated with multicolored Christmas lights and a Santa Claus, Benes has a toddler and another child on the way - and Shady Acres is a completely different place.

Clusters of gated townhouses and rows of three-story homes with Hardiplank siding have replaced sagging wood-frames and shabby apartments. On lots where one house once stood, now there are nine or 12 or 15. Parking is at such a premium that homeowners save spots using rocks the size of soccer balls.

More Information This is the last story in a series about income inequality in Houston, now at its highest level in nearly a century.

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The air is scented by the acrid smell of sawdust, punctuated by the whir of buzzsaws and steady clack of hammers. For sale signs in front of web-like scaffolding and vacant lots advertise new construction with listing prices of $380,000 and up.

Here, as in neighborhoods across Houston, gentrification has edged out longtime residents, lured in people who are younger, more affluent and mostly white, and driven up home values and property taxes. It is making neighborhoods like Shady Acres unaffordable not only for working-class folks but - increasingly - for middle-class families like the Beneses.

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The changes threaten Houston's vaunted identity as an affordable place to live and, if left unchecked, could magnify the economic segregation and income inequality of a city already ranked high in both.

Benes now wonders what she will do when it's time to upgrade, when her growing family needs a little more space, a bigger backyard.

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When even $500,000 - her price range for the next move - won't be enough to buy a house in Houston.

***

The pattern spears across the city like an arrow: rising real estate values, socioeconomic levels, surging construction and changing demographics - spreading from west to east.

This is a metropolis in flux, a place where newly built townhome developments and upscale apartment complexes cater to the affluent, reverse white flight is changing the complexion and character of inner-city neighborhoods, and low-income residents are being pushed out and away from jobs.

In the traditionally Hispanic East End, a spurt of gentrification has bumped home prices up 85 percent from 2010 to 2014, most of that within the last two years. In Third Ward, a historically black neighborhood, prices increased 125 percent over five years.

Selling prices for homes in the metro area as a whole went up 10.2 percent from 2013 to 2014, according to a report from Rice University's Shell Center for Sustainability.

The Rice analysis, authored by research fellow Lester King, found that most of the new development on the west side of Houston's inner loop - including the Shady Acres neighborhood - was no longer affordable by national standards.

Special section: Read up on earlier stories on inequality in Houston in The Divide series

Rents also have climbed 4.8 percent from last year, following a national trend resulting from a boom in luxury housing and increasing demand for affordable housing.

In Houston, the median rent is $930 - well above the $600 considered within range for low-income renters. Nearly one-fifth of the city's renters spend more than 50 percent of income on rent, while about 46 percent of renters spend more than 30 percent, said Jonathan Spader, a researcher with Harvard's Joint Center for Housing Studies.

The result, affordable housing advocates and community activists say, are swaths of Houston that have been transformed almost overnight. Gone are moderate and low-income housing options. Gone are pockets of African-American and Latino residents. In their place are neighborhoods like the Washington Avenue Corridor.

In 1990, the median income in that census tract was 50 percent of the median for Houston as a whole. Today, it is 200 percent, said Mary Lawler, executive director of Avenue CDC, a local economic development group.

The population has more than doubled, going from 2,000 to 5,000, and the demographics have shifted substantially. In 1990, whites made up 57 percent of the census tract and Latinos almost 52 percent. Today, whites are 81 percent, while Latinos are only 24 percent. The percentage of black residents has dropped by almost half.

In 2000, 80 percent of houses there were valued under $200,000. Today, none are.

"The folks getting displaced are Houstonians. They are part of the community, working low-level jobs that keep the city turning and keep Houston moving," said Charlie Duncan, a planner with the nonprofit Texas Low Income Housing Service. "This will create a whole new set of problems if we don't keep folks in the city near where they need to be."

***

On a December morning, Floyd Johnson stood outside the Wayman Chapel AME, a mainstay in Shady Acres for 110 years and his home church for just about all of his 61. He waved his hand at a column of narrow three-story houses across the street and at the construction workers perched on a rooftop a few houses down.

"See what's springing up?" Johnson said, with equal parts resignation and indignation.

Johnson, brought into the world by a midwife in his great-grandfather's white, two-bedroom wood-frame at 814 West 26th St., is part of the old Shady Acres. He spent chunks of his childhood dashing with his cousins beneath four pecan trees, flinging himself into the sky on an old rope swing, walking to Holden Elementary or strolling to Wayman.

Four generations of Johnson's family lived here. Even after his grandmother died in 2000, a cousin dreamed of one day building his own home there, Johnson said.

Then the neighborhood started to change. Homes prices shot up - and so did taxes. It became too expensive to hold on.

Now, the house is gone. So are the trees. Replaced by a set of homes differentiated only by the letter attached to the address number.

The neighbors Johnson once waved to, the ones who looked after each other's children and chided him if he did something wrong, have vanished, too, with their homes bulldozed to make room for a relentless crush of new development.

"They're all right on top of each other, happy with their little cubicles," Johnson said, shaking his head. "They take one piece of property and put six homes turning in on each other. That's ridiculous."

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Holden Elementary has become Houston ISD's Arabic Immersion School, a plus for the young, upwardly mobile families moving into the neighborhood.

Johnson, who makes a living doing HVAC work, moved just outside the Loop to Independence Heights. Then farther out, to Tidwell and Homestead, after taxes rose again.

The move to the northeast side of town has limited the jobs Johnson can take on. Traveling far south or west costs too much in time and gas.

It's just one more thing that makes him nostalgic for Shady Acres, which sits just off 610 and within easy access to downtown.

Johnson says he understands why younger families are flocking to the neighborhood he loves.

But he worries about people like him, who work blue-collar or minimum-wage jobs, the ones who can't afford expensive real estate and steep taxes.

"It used to be," he said, "that if you had two family members working, you could get by. You could find a place to stay."

***

Could gentrification turn Houston into one big "Super Zip," home only to the affluent and the elite?

Researchers, demographers and city officials, backed by a wide assortment of data sets, maps and market analyses, believe that can happen.

They all pinpoint the same areas predicted to gentrify within 20 years: Fifth Ward, Near Northside, Old Spanish Trail/South Union, Acres Homes, Independence Heights.

New development in those neighborhoods could bring an injection of businesses, increased property values, better amenities and infrastructure, improvement to schools, housing stock and quality of life.

But experts distinguish between revitalization, which can restore blighted communities, and gentrification, which results in the wholesale displacement of poor and minority residents.

They fear the economic and social costs to the city.

"I don't want to see a Houston where everywhere inside the 610 Loop are homes owned by wealthy people and no regular folks," said Neal Rackleff, director of Housing and Community Development with the city of Houston.

The city has used $178 million in federal disaster recovery funding to build or renovate low-income housing in communities identified as ripe for gentrification. Since 2010, 7,633 multi-family units have been renovated or developed through new construction, Rackleff said. Another four multi-family developments, which include a mix of market value and moderate and low-income units, are under construction.

"If we don't take steps to refresh and revitalize the housing stock, we will have people living in squalor and slums," he said. "No one wants that."

In other cities, Rackleff and others note, officials use zoning and economic incentives for developers to control gentrification and maintain quotas for affordable housing. That has not happened here.

The average Houstonian now spends 46 percent of his or her salary for housing and transportation, putting the city just above the 45 percent threshold for affordability set by the U.S. Department of Transportation.

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As housing costs rise, households have less to spend on other necessities, said Harvard's Spader. His research shows that households that pay more than 50 percent on housing spend 38 percent less on food, 55 percent less on health care and are unable to save for retirement.

The city's economy also suffers as low-income residents move from central Houston.

"Employees have a harder time getting to work, a harder time doing good work," said Amanda Timm, executive director of Local Initiatives Support Corp. Greater Houston, a nonprofit group that supports neighborhood revitalization. "There's an economic value to keeping workers close to the core."

Gentrification tends to isolate the poor from the affluent and disrupt ties and relationships that can be critical for upward mobility.

In the Near Northside, Avenue CDC is trying to prevent that through Avenue Place, which offers affordable housing. Many of those moving to the development are working families who could no longer afford to live in the Heights but wanted to stay close to downtown, said executive director Lawler.

The group's goal is to make sure 20 percent of housing there remains affordable.

Without such proactive efforts, Lawler says, "we will end up with marginalized communities without resources, without access to opportunity."

***

The sound of worship rattled the windows of Wayman AME on a recent Sunday.

Outside, rain poured over the glistening townhomes and trendy restaurants and coffee shops of the new Shady Acres.

Two dozen worshippers filled pews upholstered in mustard yellow. Most had long ago left the neighborhood but still return for service. The Rev. Hunt Harris has tried to recruit some of the newer residents. But so far, the pastor said, "I just see them drive by in their convertible Benzes."

Mary McDonald Lindsey, 63, a red flower resplendent against her dark suit, was raised in this church, just a block from her childhood home. She moved away after marriage, eventually settling in Fifth Ward, but stayed rooted to Shady Acres by faith and family.

Every week, on her way to church, Lindsey would peer down West 21st Street to catch a glimpse of the lemon meringue bungalow that her postal worker father sacrificed to build. But last year, as her mother aged into her 90s and new homes sprung up around the block, the family finally gave in and sold the property.

Last January, a sign in front of their old house announced: "New development coming."

The new owners since have lifted the house off the foundation and moved it. Only the pilings and a vacant lot remain.

These days, Lindsey no longer glances down the street, but she can't avoid change.

Construction has started creeping through her neighborhood. Townhomes are moving in.