From "Building a Companion Unit" (city of San Diego)

Granny flats can be stand-alone or attached to the main house.

Last year, San Diego opened the door wide for backyard granny flats, and not the tiny kind on wheels, but units as large as 1,200 square feet. This year brings an even bigger change. Triplexes.

Single family zoning is being transformed to help tackle the housing crisis. As of January 1, state law allows homeowners to apply to build both a granny flat and a junior unit on their property, effectively allowing a triplex.

Accessory units are among the city's Housing SD initiatives to help increase the supply of affordable homes, which is even more attainable if homeowners tack on two units to use as rentals. However, rent control, which kicked off this year, won't apply to granny flats.

Those who rent granny flats built within the last 15 years may face rising rents. The newer units are exempt from the rent cap, in which the maximum increase in a 12-month period is five percent plus inflation, and from protection from just-cause eviction.

Granny flats (or "companion units," as the city refers to them) can be stand-alone or attached to the main house, while junior units, which can be up to 500 square feet, are contained entirely within an existing, habitable single dwelling.

The new laws prohibit minimum lot size requirements, and owners aren't required to live on the property. Single-family home owner associations must comply. Opponents include the League of California Cities, which says they reduce local control.

Last year, the San Diego began a subsidy program, with $300,000 set aside to encourage people to build granny flats. Eager homeowners jumped in and exhausted the funds. For the fiscal year that began July 1, the city council upped the amount to $800,000.

In November, the city began accepting pre-approved granny flat applications for use in single-family or multi-family properties. The free floor plans reduce the costs of design and construction, which they say have held back affordable housing.

Over time, housing reforms have steadily chipped away at the problems, eliminating water and sewer capacity fees, lowering development fees and easing zoning regulations. Now, over-the-counter permits for detached one-story units, additions, conversions of garages or accessory structures can be obtained the same day.

Unlike Encinitas, where subsidies were slow to spark growth, in San Diego the measures have been working. According to the city's website, in 2017, they received 142 applications and saw 15 units through completion. In 2019, the numbers soared to 545 applications, and 179 finished units.

When an earlier round of incentives was brought forward, no one saw triplexes coming, including those who helped push the granny flat program.

“The three barriers to building companion units are regulatory ordinance barriers, excessive fees, and ease of permitting," said city councilmember Scott Sherman.