Thinking of extending your property’s square footage yet you’re looking for a detached unit where your college student or in-laws can live away from the main house? You may want to consider building an accessory dwelling unit, or ADU, on your property. You’ll need an experienced San Francisco builder on your side who has a deep knowledge of not only construction of ADUs but the rules and regulations for the Bay Area that come with them.

ADUs: Defined

What exactly is an accessory dwelling unit? ADUs are small and independent residential dwelling units that are located on the same lot as a detached single-family home. Also called secondary suites or granny flats, ADUs can be:

  • Additions to new or existing homes (attached ADUs)
  • Converted portions of existing homes (internal ADUs)
  • New stand-alone accessory structures or converted parts of existing stand-alone accessory structures (detached ADUs)

No matter which option you choose, ADUs can increase affordability of housing for both homeowners and tenants, offer a wider range of housing options within a community, allow aging seniors to stay close to their families, and enable better use of the existing housing structure in an established neighborhood. In a nutshell, ADUs can increase the housing supply without altering the existing neighborhood character.

In addition to the aging population and rentals, there are many reasons why parents are choosing to integrate an ADU on their property to accommodate their adult children. ADUs for this purpose:

  • Provide a safe harbor for children yet allow for the maintenance of independence for both parties.
  • Allow parents to have their children on the same property as their main home.
  • Cost less money than buying their children a single-family home.
  • Provide the opportunity to rent out the ADU for additional income.

There are certain zoning regulations that go along with the creation or conversion of an ADU in many cities and towns, and the Bay Area is no different. Before building an ADU, it helps to gain knowledge of the local rules and regulations, as well as how to navigate the application and permitting process.

A Look at Bay Area ADU Regulations

California has recent laws in place that govern ADUs across the state that would allow these units to be added to single- and multi-family buildings. Infill housing is a big topic in the residential design world. This involves inserting additional housing units into an already-approved neighborhood. Because the SF Bay Area prioritized single-family homes for so long, contributing to urban sprawl, the popularity of infill housing is now on the rise.

Recent laws have streamlined many of the ADU building processes. For instance, Bills AB-881 and AB-68 removed certain lot restrictions so municipalities can’t readily block ADU construction any longer; Bill SB-13 got rid of the impact fee for ADUs smaller in size than 750 square feet, making it much cheaper to construct ADUs; and Bill AB-670 prevents Homeowners Associations from unreasonably restricting or banning ADUs.

Now, what happens if your property carries a historic designation? Does that prohibit you from building an ADU? Not necessarily. It’s very possible you can still do it, but you will have to incorporate the architectural elements and style of the main dwelling.

What happens if your home is located within a designated “landslide” or geohazard” zone? You will have to obtain a Geologic Hazard Clearance permit, which your builder should be able to take care of for you.

If there is an easement on the property, there are additional ADU requirements. You may need a copy of the title report you got when you purchased your home. The deed will specify your home’s designation.

Property Taxes and ADUs

In the Bay Area, property taxes are usually about one percent of the assessed market value. When you build an ADU, this will trigger a reassessment by the town. However, this will be a blended assessment, which means the ADU will be assessed on its own. The determined market value will be assessed a one percent tax and will be added to your next tax bill, resulting in a blended rate. While your tax rate can increase over the years, it will be capped at two percent.

Schedule an ADU Consultation With Asher Brothers Construction

Now that you know all about building an ADU on your property, let the pros at Asher Brothers Construction take over. We know the regulations for ADUs inside and out for the Bay Area, so you’re in good hands. Schedule your consultation today or give us a call at (925) 406-4776