Living on a fixed income, Anna didn’t know what to do when her Pacifica landlord doubled the rent.  Bill and Ruthie in Half Moon Bay wanted to give their adult developmentally challenged son his own space but had few feasible housing options. Surinder sought a way to generate income from her Menlo Oaks property. Three different cases, one growingly simple answer — second units.

These local success stories are among the examples, tips and tools offered on the new Second Unit Resources Center, a one-stop webpage developed by regional housing initiative Home for All. Also known as in-law suits, granny flats and accessory dwelling units, these self-contained secondary housing options benefit their owners and contribute to filling the housing gap on the Peninsula.

Visitors to can be inspired by real-life stories, consider very real floorplans design templates, calculate potential costs and learn about specific construction and permit regulations in the city or unincorporated area where they live.

“Recent changes to state law make the process of building a second unit more streamlined and efficient. And in fact, they are one of the simplest solutions to expand housing in our single-family residential neighborhoods,” said County Supervisor Warren Slocum, who co-chairs Home for All . “But the partners in Home for All realize the process can still be daunting which is why we created the Second Unit Resources Center to help homeowners navigate the steps through this opportunity.”

Home for All formally unveiled the Second Unit Resources Center last week at a convening of its members and other stakeholders. Author Kol Peterson, owner of the world’s first tiny house hotel and author of “Backdoor Revolution — the Definitive Guide to ADU Development,” addressed the group about how the second unit success of Portland, Oregon might be replicated here.

“ADUs are going to become very mainstream in the next two to five years in major U.S. cities. ADUs are poised to present a viable solution for cities that are experiencing a housing crisis, and exploring how to increasing housing opportunities within their single family residential zones,” Peterson said.

In San Mateo County, those opportunities are abundant.  A 2017 study by U.C. Berkeley’s Center for Community Innovation concluded that:

·         In the unincorporated area of the county alone, there are 726 permitted second units;

·         In the same area, the study identified 15187 parcels that could accommodate a second unit based on recently updated County regulations;

·         Approximately 54 percent of single-family homes in the county are deemed “underutilized,” meaning they have more bedrooms than occupants;

·         18 percent of homes in the county have adult children;

·         7 percent of homes include extended family.

County housing and planning staff also project that building a $100,000 second unit and renting it out at market rate could produce cumulative net income of more than $1 million over 30 years.

“In an area like ours which has more jobs than homes and limited space for development of new affordable housing, adding these units to existing parcels can be a win-win,” said County Supervisor and Home for All Co-Chair Don Horsley “They help families stay together, ease traffic by providing a home closer to a Peninsula job and offer the chance for extra income.”

Solving the problems of housing and traffic spurred the Closing the Jobs/Housing Taskforce in 2016. That taskforce developed a menu of possible housing solutions that each jurisdiction could tailor for its own needs and established a work plan for the subsequent Home for All initiative. Along with securing support, funding and land, the initiative also set out to establish an online Second Unit Center.

“I am proud to see this goal come to fruition and will be even prouder when we see the growing number of second units strengthening the fabric of our community,” Horsley said.

The Second Unit Resources Center does not address issues related to unpermitted second units. However, the Board of Supervisors at is Jan. 23, 2018, meeting did adopt a Second Unit Amnesty Program to rehabilitate and improve the safety of such units in the unincorporated area.

About Home for All:

The Home for All Initiative builds on the work of the Closing the Jobs/Housing Gap Task Force and is led by County Supervisors Don Horsley and Warren Slocum. Members include the County, its cities, community partners and agencies focused on housing, education and government. It’s mission is closing the 26:1 jobs/housing gap through collaborative efforts and establishing a climate in San Mateo County where a diversity of housing is produced and preserved. Learn more at