Bay Area’s housing crisis: Can accessory dwelling units help?

One solution to the housing crisis gripping the North Bay and the rest of the San Francisco region is to add homes to the ones that already exist, according to Marin County-based advocate for accessory dwelling units.

Also called in-law apartments and granny flats, these are additional housing on existing lots zoned for single-family housing. More than just a rented room, they are spaces set up for living independently from the main home. Depending on local rules, they can have their own bathrooms and kitchens, and may be inside, attached or detached from the house.

“I refer to this as flexible housing, because our needs for our homes are changing,” said Rachel Ginis, founder and CEO ?of Lilypad Homes.“And we need to create flexibility in them.”

The majority of U.S. housing are single-family dwellings, 60 percent of it built after World War II with a particular focus on the “nuclear family” of a father, mother and one child, said the anthropologist turned general contractor at the North Bay Business Journal’s Construction Industry Conference.

“We are in the midst of a massive housing crisis, but at the same time we are amazingly overhoused,” Ginis said. “People who need housing are everybody who is left over.”

Those include single-parent families, couples without kids, retirees, empty-nesters millennial professionals.

Portland, Ore., is considered the hub of accessory dwellings in the U.S., but Vancouver, British Columbia, is a leader in North America for this style of living, Ginis noted. About 35 percent of homes in that Canadian metropolis have legal accessory units.

Three common types of accessory dwelling units are cottages, conversions and carveouts. The development costs of a cottage, which is detached, in the North Bay can be $200,000–$400,000, Ginis said. Conversions of an unconditioned space such as a garage or basement into a dwelling can be $100,000–$200,000. Separating a room or area of a home into a unit, with its own private entrance, can cost $10,000–$100,000. A subset of carveouts is the junior accessory dwelling unit, which can also have a door into the main home and cost $10,000–$50,000.

“Where in the North Bay, and the Bay Area in general, can you build a single-family home, now under state law of up to 1,200 square feet - but every jurisdiction is different - for under a half-million dollars?” Ginis asked.

Adding accessory dwellings can boost the value of the property by up to 60 percent over homes without them, according to a Nov. 6, 2014, Wall Street Journal story that quoted a survey by real estate information and listings firm Zillow.

“I’m proposing the most in-your-back-yard solution for housing you can possibly come up with,” Ginis said.

Jeff Quackenbush (jquackenbush@busjrnl.com, 707-521-4256) covers construction, commercial real estate and wine.