Such multigenerational housing is specifically aimed at the booming immigrant population in the Bay Area, and is emerging as one of the few growth niches in a moribund housing market.

“If you’re selling in certain areas of the Bay Area, you have to be more extended-family-oriented,” said Cheryl O’Conner, government affairs consultant to the Building Industry Association of the Bay Area.

Asian buyers, in particular, “come with the whole family,” Ms. O’Conner said. “They come with their parents and grandparents, uncles, aunts and cousins.”

Even when several generations are not living together permanently, more and more families are looking for housing alternatives that can readily accommodate extended visits from overseas relatives.

Census figures released last month show the Bay Area’s Hispanic and Asian populations each increased by more than 350,000 over the past decade, while the region’s non-Hispanic white population declined. Those groups are about twice as likely as whites to live in multigenerational households, according to a 2010 study by the Pew Hispanic Center.

In 2008, an estimated 49 million Americans lived in a house that included at least two adult generations or a grandparent and at least one other generation, the study showed. In 1980, that figure was just 28 million.

“Immigrants are a source of growing demand, and their household composition is different in fundamental ways from the domestic-born,” said Kermit Baker, a senior fellow at the Joint Center for Housing Studies at Harvard and the chief economist of the American Institute of Architects.

In Taylor Morrison’s development in Sunnyvale, called Duane Court, most units will be approximately 2,000 square feet, featuring a bedroom and a bathroom on the ground floor so older-generation residents do not have to use the stairs; a kitchen, a living room and a dining room on the middle floor; and three additional bedrooms and two bathrooms on the top floor for the traditional nuclear family unit.

Local officials are enthusiastic about the trend. Melinda Hamilton, mayor of Sunnyvale, said the new project “has more community support because it’s more in tune with the neighborhood, and it provides what we need: housing for families.”

Such designs are particularly popular in the South Bay, observers say, because of the large influx of engineers from China and India who want large homes to accommodate their extended families and who can afford an expensive new townhome.

But multigeneration housing is gaining popularity in less wealthy neighborhoods, too. In East Oakland, the developer Korin Crawford finished a nine-unit townhome development with a design similar to Duane Court’s in 2009; he was unable to sell the units in the middle of the housing bust but has rented them out and is pushing ahead with similar projects.

On Third Street in the Bayview district of San Francisco, the affordable-housing developer Bridge Housing completed its 124-unit Armstrong Townhome project in 2009. Seventy units have sold, and Bridge Housing’s project director, Kevin Griffith, said he believed the rest would sell by early next year.

Mr. Griffith said his company’s architects were also mindful of multigenerational needs, designing some units with a bedroom and a full bath on the main level so the elderly could avoid the stairs.

Design preferences can vary among ethnicities, social classes and income levels. Amar Gupta, managing editor of the Indian-interest magazine Siliconeer, is not convinced that South Asian immigrants will go for town houses like those at Duane Court, for example, because they prefer large, detached single-family homes built across either one or two floors.

aglantz@baycitizen.org

Article source: http://www.nytimes.com/2011/04/22/us/22cncmultigenerational.html