Pardee Homes, which has built and sold 80,000 units in its 87 years, is opening new developments in Riverside County where the smallest models are smaller than they've been in five years, said Matt Sauls, the company's regional director of marketing. In a Lake Elsinore development, the smallest model will be 1,350 square feet, and one in Beaumont will be 1,150 square feet.

Nationally, the average size of a home built last year fell to 2,400 square feet, down 100 square feet from 2008, according to a survey from the National Association of Home Builders. The percentage of homes with three or more bathrooms fell for the first time since 1992.

The trend reaches all the way down to boutique homebuilders.

"I'm tending to build smaller than I would have during the boom. If I was going to build a 3,200-square-foot home then, I would have my homes today (at) 2,800 square feet," said Scot Sandstrom, a specialist who focuses on rebuilding homes destroyed by the 2003 and 2007 wildfires.

The shrinkage stems partly from a change in bank-lending rules that keep buyers from getting the no-documentation mortgages needed to prop up demand for expensive houses, but also from dramatically reduced property prices. A 7,000-square-foot lot in Vista, complete with grading and access to water, sewer and electricity, now sells for as little as $100,000, way down from $250,000 in 2005, said Robert Thorne, CEO of California West Communities in Carlsbad.

Lower property prices and smaller homes have allowed California West to drop the price of its homes. One new development in 4S Ranch, near Rancho Bernardo, has smaller homes selling for $600,000 to $700,000 each, whereas in the boom, bigger homes on the same lots could have been priced up to $1 million.

California West was so concerned about high land prices in 2005 and 2006 that it cut back and laid off staff at the peak of the boom, dropping from nine ongoing developments to two, one of which it later suspended for a year. Now the company has four communities, including two in 4S Ranch, going up for sale this month and in February, all of which are reduced in size.

Most builders are saving space by eliminating formal rooms, such as a dining room and a living room, in exchange for a "great room" layout, which combine several functions into one room, and opening the kitchen to the living space.

Builders also said they're building many more single-story homes than they did during the boom.

"We can compete against resale very well with our new single-story homes, and offer more per foot," said KB Homes' Ruffner.

California West's floor plans no longer include the two- or three-story living room, a staple of boom-year construction.

"We've eliminated the volume in the second story of the homes; that allows us to lay out the second story more efficiently, which means bigger bedrooms," Thorne said.

Builders also are emphasizing energy efficiency in the new construction, including heat-reflective panels for ceilings, double-paned windows, and efficient hot water heaters. While some of these are mandated by new California building codes, some builders are going beyond the requirements. A quarter of all American homes built last year met the standards necessary to receive the Environmental Protection Agency's Energy Star rating, up 11 percent from 2007. Sandstrom said he installed solar panels as standard equipment on the 16 homes he's built.

Many of the new floor plans incorporate concepts from a 10-year-old book written by North Carolina architect Sarah Susanka, called "The Not So Big House." After a decade of pleading with builders to go small and use the savings to improve the quality of homes, she's finally seeing her ideas come to fruition, and she's optimistic that smaller homes will be a permanent feature of the landscape.

"I think they'll stick around," she said. "These things go in waves. A wave of smaller, better-designed product is coming on-line, that will precipitate the interest, because people will see it and say, 'I want one of those.' It's coming, and it's a very positive step forward."

Building less than the maximum house is hardly a new idea in the world, but for the last decade, North Carolina architect Sarah Susanka has been preaching to a half-filled hall.

Susanka, the author of "The Not So Big House," has started a small movement within architecture circles for smaller, better-built homes ---- but her audience has rarely included major developers.

"In the production housing market, there's been this belief that taller is better," Susanka said. "That looks great in a photograph and it looks pretty good when you have a lot of people walking through a model home. But it's very difficult to feel comfortable in a tall space. We have this collision."

Susanka believes people can live more comfortably in smaller spaces that are well designed for their needs and that smaller houses can be designed to feel big. As an example, she said a home with a window that runs to the corner of the house can make the yard feel like an extension of the home, in contrast to a much larger sliding glass door built in the middle of the wall.

At a recent convention of builders, she was thrilled to hear vendors talking about better design, "singing my song," she said. But while she thinks the recent trend is a good step, permanently changing the housing culture will take awhile.

"We may take two or three more economic downturns to end up with a house that is better proportioned for our human form and really fits us," she said