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Design Finance LifeStyles Real Estate


By Christina Warmerdam

San Diego has piloted a 5-year program to creatively tackle the affordable housing shortage by easing restrictions for homeowners wanting to build small dwellings on the same property as their existing homes.

ADU stands for “Accessory Dwelling Unit”, often referred to as guest houses, granny-flats, or mother-in-law suites. They are desirable for many homeowners wanting additional, but independent space for over-flow guests, elderly parents, returning adult children, or caretakers.

Prior to 2018, building a new Accessory Dwelling Unit in San Diego was time consuming, cost-prohibitive, and stressful for many property owners. Changes to local and state laws, aimed at increasing affordable housing, have diminished, or removed many of these barriers. By enacting fee waivers, and providing free, pre-approved plans, the ADU program greatly reduces the upfront costs associated with the planning stage.

“Depending on the size and type of construction, and permitting and inspection costs, recovery fees can be as low as $2,000 per application. Previously, the cost was between $20,000 and $30,000,” Gary Geiler, Deputy Director of San Diego’s Development Services Department.

By all measures, San Diego’s ADU program has already seen great success. Applications have skyrocketed from previous years. In 2019, 763 applications were submitted, compared to just 16 in 2016 according to


Step 1 – consider your site location. Check your city’s local building zoning laws. Each city still has its own zoning laws that need to be met. Following codes such as set-back laws are\ crucial in determining if your project is viable. Luckily, this information is easily located online.

Step 2 – consider your floorplan options. Again, check your city’s building department website. Some cities, like Encinitas, have partnered with local design-build firms to create free, attractive ADU plans that can be customized to incorporate the surrounding neighborhood’s character.

Step 3 – find a builder/contractor. This is likely the most important decision you will make. Fortunately, with the massive rise in popularity of ADU’s, has come a swell of companies with tons of experience building them. Some builders even have sample ADU’s open for tours.


  • Maximum allowed square footage is 50% of existing residence up to a maximum of 1200 sq/ft.
  • Not approved for short-term vacation rentals! ADUs must rent for at least 30-days or family housing only.
  • Owner occupancy requires that the homeowner either live in the ADU or in the primary dwelling. Owner occupancy has been removed in all jurisdictions in California until the year 2025. Any homeowner who builds an ADU from 2020-2025 will forever be grandfathered into no owner occupancy requirement even if the legislation changes to require owner occupancy in the future. (

Incorporating an ADU to your existing property can bring extra rental income while increasing your overall property value. For the next four years, at least, the city and county of San Diego are trying to make this potential “wish” a reality for San Diego homeowners.


Our publisher, Tracy, started the ADU process at the end of September. She needed additional living space for her father who has been dramatically affected by the quarantine. After gathering information from a few local companies she decided on Instant Guest Homes. “The owner, Michael Avery, made everything easy. Before returning my call he looked up the zoning regulations in my area, googled mapped my home to look at my backyard, and then called me with a bunch of information and ideas. He was great!” She chose a Prefab ADU about 426 square feet.

The next day Tracy viewed an existing Prefab ADU in Point Loma and two days after that met with the whole Instant Guest Homes Crew: crane operator, plumber, electrician, concrete/ slab contractor and the project manager. The plans were submitted to the city 5 days later. “Michael even helped me submit the project to my HOA, which approved the project in just 8 days. It was completely stress free.”

With COVID-19 the city is working all online, slowing the process a bit. Five weeks later they were assigned a Plan Checker from the City’s Development Services Department. Tracy will give us an update next month and will photograph the entire process so our readers can see the project start to finish and learn along the way. We look forward to this 3 Part Series and hope you do too!

*Rendering from Instant Guest Homes

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