Two Story ADUs in San Diego

The new wave of ADUs popping up in Southern California neighborhoods continues to captivate the attention of homeowners and renters alike. However, the build process just got more interesting, as two story ADUs have increased in popularity in recent months. These two-story structures are a great way to maximize square footage without compromising additional outdoor space. Below, you will find all the information necessary to get you up to speed on the two-story trend, and help you decide if this is the best option for you.

Can an ADU be two stories?

In short, yes, an ADU can be two stories in many municipalities in greater San Diego! While California state law does not require that local jurisdictions allow two story ADUs, many cities – including San Diego, Oceanside, Chula Vista, El Cajon, Encinitas, Escondido – allow ADUs to be two stories. Some still allow you to take advantage of reduced side and rear setbacks, while others will require a 2 story ADU stay consistent with the underlying zoning. Also note that some cities have specified height limits for ADUs over garages. Height regulations vary by city, which we have summarized for you in our individual city regulations pages.

What types of two-story guest houses are there?

Overall, there are three different ways two get to a two story ADU or casita:

  1. ADU Over Garage

    As you could imagine, an ADU over a garage refers to an ADU built with a garage below it. The staircase up to the ADU can be external to the structure or internal. A two-car garage can comfortably have a one bedroom ADU above it.

  2. Two Story ADU

    A two story ADU is the classic example of a two story living space and is similar to a two story home. Both stories are joined by a staircase and you are able to reside in the entire building.

  3. Stacked ADUs

    With stacked ADUs, the two stories are individual residences that are not internally connected. Typically, an outside staircase will allow you to access the upstairs unit.

The structure of your ADU is largely limited only by your budget and imagination. However, you should be sure to keep up on local regulations and ordinances to determine whether your vision is realistic given your location. This is something your contractor will be able to inform you of, especially if they conduct a feasibility study. These studies determine if there are any watch outs that might come along with your build before actual construction begins.

How tall can your ADU be in San Diego?

The height of your ADU will be dictated by local regulations. We have put together a summary of the height limits and two story regulations across San Diego in the chart below.

 

JURISDICTION

ADU OVER
GARAGE

TWO-STORY
ADU

STACKED
ADU

 Carlsbad

 Yes, with underlying setbacks.  No  No

 Chula Vista

 Yes, so long as it does not exceed the height limit for the primary residence in accordance with the underlying zone.  Yes, so long as it does not exceed the height limit for the primary residence in accordance with the underlying zone.  It is currently undetermined if two detached ADUs can be attached to each other; this will be subject to city interpretation.

 County of
San Diego

 Yes, limited to twenty four feet in height.  Yes, limited to twenty four feet in height.  No

 Del Mar

 No  No  No

 El Cajon

 Yes, so long as it does not exceed the height limit for the primary residence in accordance with the underlying zone.  Yes, limited to twenty feet in height.  Attaching ADUs may be allowed if the overall building footprint does not exceed 1,200 sqft.

 Encinitas

 Yes, so long as it does not exceed the height limit for the primary residence in accordance with the underlying zone.  Yes, so long as it does not exceed the height limit for the primary residence in accordance with the underlying zone.  No

 Escondido

 Yes, up to 24′, and conforming to the height limits of the zone (which may be less than 24′).  Yes, up to 24′, and conforming to the height limits of the zone (which may be less than 24′).  It is currently undetermined if two detached ADUs can be attached to each other; this will be subject to city interpretation.

 Fallbrook

 Yes, limited to twenty four feet in height.  Yes, limited to twenty four feet in height.  No

 La Mesa

 Yes, only if ADU meets required setbacks for underlying zone.  Yes, only if ADU meets required setbacks for underlying zone.  It is currently undetermined if two detached ADUs can be attached to each other; this will be subject to city interpretation.

 Oceanside

 Yes, only if ADU meets required setbacks for underlying zone.  Yes, only if ADU meets required setbacks for underlying zone.  No, unless the ADUs meet the required setbacks for the SFR, in which case the height may be allowed to match the existing residence.

 Poway

 Yes, only if ADU meets required setbacks for underlying zone.  Yes, only if ADU meets required setbacks for underlying zone.  No, unless the ADUs meet the required setbacks for the SFR, in which case the height may be allowed to match the existing residence.

 San Diego

 Yes, up to 21′ for flat-roofed structures and up to 30′ for sloped-roof structures, and consistent with setbacks for underlying zone.  Yes, up to the height maximums for the underlying zone.  Yes, only if ADU meets required setbacks for the underlying zone.

 San Marcos

 Yes, only if ADU meets required setbacks for the underlying zone.  Yes, only if ADU meets required setbacks for the underlying zone.  No

 Solana Beach

 It is currently undetermined if a detached ADU can be attached to an existing garage; this will be subject to city interpretation.  Yes  No

 Vista

 Yes, only if ADU meets required setbacks for the underlying zone.  A 2nd story may be approved, provided it is determined the structure is not out of character with the neighborhood and existing primary structure.  No

Can you build an ADU over a garage?

In above-garage ADUs, you have the option of either adding an ADU on top of your existing garage, or building an entirely new building with an ADU above and garage underneath. Adding an ADU above an existing garage is often more difficult to budget for, as the existing condition of your house will impact the build price. For example, the existing structure may need to be reinforced to support the ADU addition.

How much does it cost to build a 2 story ADU?

A two story ADU will vary in price, due to the complexity of the build. Additional materials and manpower are necessary, so the vertical build price will be anywhere between $300K-$400K depending on finishes. See pricing for building our two-story ADUs.

Two story units require reinforced foundations, staircases, and additional labor & materials to reach and complete the upper levels. This is for items like scaffolding for stucco & siding work, and carrying equipment up a flight of stairs. Additionally, two story units may require larger air handling units.

Many contractors charge based on square footage when constructing an ADU, so it is important to research the ADU costs and pricing breakdown surrounding your entire design & build process.

Type Size Vertical Build Cost Cost per sqft Typical All-In Cost Cost per sqft View Example Plans & Prices
2BR/2BA 965 sqft $320K $330 $370K $385 2 story plans <1000 sqft
4BR/2BA 1200 sqft $340K $285 $400K $335 2 story plans >1000 sqft

Source: Snap ADU (updated February 2022)

What does a 2 story ADU floorplan look like?

Like any other ADU, a two story floorplan can vary quite a bit. There are a number of examples on our two story ADU floorplan page, which can give you a better idea of the various designs available to you. As mentioned above, your ADU design is largely limited to your budget and imagination. However, it is important to be aware of the various considerations regarding your location.