The Granny Flat Grows Up

A Santa Cruz program promotes garage conversions as an alternative to sprawl.

Like many desirable places to live, Santa Cruz, California, suffers from a lack of affordable housing. But in recent years the city, located 70 miles south of San Francisco, has initiated an impressive program to combat the problem by promoting Accessory Dwelling Units (ADUs), or “granny flats,” on single-family lots. For years the state of California has been pushing its municipalities to loosen restrictions on ADUs, seeing them as a low-cost way to accommodate surging population growth without increasing sprawl. But the Santa Cruz program—which recently won an AIA award for urban planning—goes several steps further in its embrace of the humble garage conversion.

The program has three major components. In 2002 Santa Cruz changed local zoning regulations, which helped encourage the construction of ADUs. Then using a grant from the California Pollution Control Financing Authority, the city created a comprehensive manual—a kind of how-to guide for ADU planning, approval, and construction—including seven prototype designs. (The manual can be accessed through the city’s Web site: To make units more affordable, the city also offered low-interest loans through a local credit union.

All but one of the prototypes (a studio) are one-bedroom units with about 500 square feet of living space, in styles ranging from traditional to modern with designs that incorporate different site conditions and material approaches (including sustainable options). According to Carol Berg—the city’s housing and community development manager who spearheaded the program—the designs are intended to be highly adaptable and can serve as either aesthetic guides or actual plans, which are sold individually for $22. “Since we want them to work with an architect or contractor, the plans aren’t off the shelf,” she says. “We refer to them as ‘reviewed’ plans. This means they’re easier to get through the approval process.”

“Like San Francisco, Santa Cruz is politically liberal but aesthetically quite conservative,” says Cass Calder Smith, one of the architects hired to create a prototype for the program. “The city knew that one of the biggest hurdles would be perception. Their fear was that people might accept the program in the abstract but wouldn’t want one of these units in their backyard—or in their neighbor’s backyard.”

So far the number of units built using the preapproved plans remains small. “They’re slowly coming on board,” Berg says. “We’ve conducted a large outreach program and have seen a fairly substantial increase in permits—from eleven in 2002 to forty-five last year.” But she says the intent of the program was not to build ADUs exactly as shown in the manual. “We’re encouraging people to use the manual for guidance, ideas, and direction. It’s really about creating more rental units in the city.”

Recent Programs