California's builders aim for super-energy-efficient homes

Crowned with three gables and painted in hues of grey and white, the suburban home in Lake Forest, California, doesn't look much like the domicile of the future.

But as summer heat radiates off the fresh asphalt outside, the home runs comfortably at full tilt indoors. Recessed lights shine, radios blare and air-conditioned splendour greets hot skin. Despite all systems going, the property is producing more electricity than it can consume on a warm summer day - and that's the goal.

The ZeroHouse model by Los Angeles builder KB Home embodies the industry's bid to move beyond the one-of-a-kind vanity project and make subdivision building a green practice. Net-zero homes such as the one KB Home has built are highly efficient properties paired with renewable energy technology such as solar panel systems, resulting in homes so green they produce at least as much juice as they consume.

California has had expansive policies mandating and incentivising the development of greener new homes for years, but the implementation of those goals has been slowed by the weak housing market and the dearth of new construction.

With the market healing, and with builders trying to distinguish their products from homes they built as recently as six years ago, companies such as KB Home, Lennar Corp and others are rolling out more options for consumers and increasingly making energy efficiency part of the basic package.

"For new homes, it is becoming more of a standard feature, and the reason is that builders need a compelling reason that somebody should buy a new home rather than a resale," said Patrick Duffy, of research firm MetroIntelligence Real Estate Advisors.