Washington McMansions are sprouting in the suburbs of Washington and Atlanta, in southern Connecticut and out West in Utah as an appetite for bigger homes just keeps on growing.
One in five American houses had at least four bedrooms in 2005. That's up from one in six in 1990, despite shrinking families and increasing costs for construction and energy.
Houses with five or more bedrooms were the fastest-growing type in that time, adding to the nation's consumption of resources and reputation for excess.
"In this country, bigger is better," said Gopal Ahluwalia, vice president of economic research at the National Association of Home Builders. "This is true for houses and this is true for automobiles."
Utah leads the nation with nearly 40 percent of homes having at least four bedrooms, according to a report Tuesday by the Census Bureau. Demand is high in part because Utah has more people per household (3.07) than any other state.
Evan and Valerie Astle are having a 5,700-square-foot house built in a new subdivision near Ogden because they want more space for their three teenagers. They have been renting a storage unit while living in their old, 2,100-square foot home.
Storage won't be a problem in the new house, which has four big bedrooms, 3 1/2 bathrooms and a three-car garage.
"Our kids have more stuff. They need more living space," said Valerie Astle, a grade-school teacher. "Our (old) house was fine when they were small, but we've just outgrown it."
Among states with the biggest percentage of large homes, Utah was followed by Maryland, Virginia, Colorado and Minnesota. Arkansas had the smallest share, at 12.6 percent.
In much of the country, the growth in big houses is fueled by suburban homebuyers seeking luxury, rather than big families needing space, Ahluwalia said.
"They are buying for lifestyle," he said.
Nationally, the average household size has shrunk slightly since 1990, to about 2.6 people. Meanwhile, the average new house grew by nearly 400 square feet, to 2,434 square feet.
"You cannot sell a new home today with 1 1/2 bathrooms," Ahluwalia said. "Even if only two people are in house, they still want 2 1/2 to three bathrooms."
Dale Mattison, a real estate broker in the Washington area, said smaller families are getting creative with all those extra rooms. One option: his and her offices.
Some bedrooms are converted into dens, but many big houses already have those, Mattison said. They also have media rooms, which used to be called TV rooms back when there were fewer electronic devices to choose from.
Homes in the United States are much bigger than they are in other countries, according to figures compiled by the United Nations.
American homes, on average, are nearly twice as large as those in many European countries, including Britain, France and Germany. Only Luxembourg comes close among European nations, with average homes about three-quarters the size of those in the United States.
U.S. homes are also becoming more expensive. The median home value jumped more than 40 percent from 1990 to 2005, to about $167,500.
Most big homes in the U.S. are going up in the suburbs, contributing to sprawl and congestion, said Vicky Markham, director of the Center for Environment and Population.
All those big suburban houses require more land, more materials to build and more energy to heat and cool, Markham said
"Excess is a matter of how each person views their own life," Markham said. But, she added, "Each person today is taking up more resources, more land, more energy than generations before."