When big is too big, even in L.A.

The city approves one neighborhood's move to block mammoth homes on small plots.

Leaning on the wrought-iron fence that defines the front lawn of his cottage-size home, Marty Greer says he doesn't like what is happening to this California foothill community.

"They're tearing down homes like mine and putting up homes like those," says the 31-year resident, pointing to a two-story home one block away. The magenta-stucco home dwarfs the one-story bungalows that line these hillside streets. Its walls stretch to the edges of the property line, not even leaving room for a swath of yard.

"I don't like it and the neighbors here don't like it," says Mr. Greer, who bought his 500-sq.-ft. home here in 1974. "It'll change this place forever."

The trend toward building ever bigger houses, which has gained momentum for over a decade in suburbs across the nation, has now arrived in one of America's largest bedroom communities: the San Fernando Valley. This week the Los Angeles City Council approved the first "anti-mansionization" ordinance in one small section of the country's second-largest city. More L.A. enclaves are lined up to follow suit.

"Mansionization has become one of the most pressing issues in my district," says Wendy Gruel, the city councilwoman who sponsored the legislation, which goes into effect immediately upon formal approval this week. The measure will limit homes built on lots of 8,000 sq. ft. or less to 2,400 sq. ft. - or 40 percent of the lot size, whichever is greater. The move affects just one community of her district (known as Sunland-Tujunga). Neighboring towns of Pasadena, Glendale, and Burbank have visited the issue, some coming up with similar ordinances, and Ms. Gruel says other areas of the San Fernando Valley are clamoring for their own laws as well.

"It's a quality of life issue that goes to the heart of many of the values that Americans cherish," says Gruel.

As in other cities across the US where the issue has already forced a clash of values, long-established residents are rankled by prospective owners who want bigger or different styles of homes. Developers actively promote the benefits of building as do some city officials eager to gain the benefits of higher property taxes that support school, police, and fire departments.

The trend also reflects changes in how Americans view their nests and how they use them.

Younger generations, who often want bigger rooms for electronic entertainment and state-of-the-art kitchens, eschew the millions of pill-box homes built after World War II. Immigrants from Asia, Iran, and the Middle East have dreams of homes with cathedral ceilings and often say they have little use for spacious yards.

The trend also reflects a shift in investment strategies away from the stock market to property and housing. Another factor is simply workers who want to combine a shorter commute and access to a downtown cultural life with the ample square footage found in exurbia.

"This is a phenomenon that is impacting every city and community in America," says Siim Soot, research professor at the Urban Transportation Center, University of Illinois at Chicago. "For decades, the demographic trend has been for cities to sprawl further and further outward because of the American sense of dream and entitlement to own one's home. Now more and more are looking at ways to achieve that by altering the very idea of residence in already established communities."

Buying an older home and then demolishing it to rebuild a larger home is an increasingly attractive financial option to buyers over finding a bigger home in newer communities that are farther away, say Mr. Soot and others.

"This is driven by the price of land elsewhere, the choice of people not to live so far from employment, changing ways of American life by Americans, and the desire for immigrants to design their own dream," says Joel Kotkin, author of several books on urban development.

Here in California, which is cradled by mountains on one side, the limits of sprawl are aided, in part, by geography. While residents like Greer have often lined up to complain about a loss of tradition and sense of place, some analysts have a more positive take: the mitigation of further sprawl already rampant in the area east of Los Angeles. "I am pleased by the trend by some builders and home buyers to build bigger homes on smaller lots because it restricts the overall expansion of urban areas into wild and still-green areas," says Soot.

In other communities of the San Fernando Valley, the issue is also drawing debate, including Valley Glen, Mount Washington, and Glassell Park. But national observers say that despite the struggles, compromises can be reached.

"We have found that communities here have learned on a region by region basis, with each one learning at a different rate," says Glenn Geiger, a real estate land-use analyst in New Jersey. "Each one has tried to address how to balance retaining community character alongside the economic growth needed to continue to thrive. The answers are different in different areas."