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, 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 ADU 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 (Carriage House)

   As you could imagine, an ADU over a garage refers to an ADU built with a garage below it, sometimes called a “carriage house.” 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.

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 $350K-$450K 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. Or if you are thinking about a prefab two story ADU, be sure to check the all-in costs.