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Building an ADU in Coronado

Accessory Dwelling Units (ADUs) have been increasing in popularity throughout California. It's no wonder that many current and future Coronado homeowners are trying to better understand their options when considering an ADU. Here we will explore more about building an Accessory Dwelling Unit in Coronado.

Often called guest houses or granny flats, an Accessory Dwelling Unit is a way for homeowners to construct a second unit to provide additional housing for family members or to rent it out for an additional income stream. There are two types of ADUs that homeowners can construct on their single-family lot, a junior ADU and a regular ADU. Junior ADUs must be built within existing living space or in a converted garage space but cannot exceed 500 square feet. Regular ADUs can be built as a stand alone or connected to an existing home and can be up to 850 square feet for a one bedroom or 1,000 square feet for a two bedroom. One big implication of converting an existing garage is that the parking must be replaced elsewhere on the property. Coronado is unique in this parking requirement due to the city's Certified Local Coastal Program approved in 1983. Parking is a requirement for single family residences to maintain public access to the coast. The California Coastal Act of 1976 is neither superseded nor in any way altered or lessened as provided for in Government Code Section 65852.2(I). It is important to note that due to this regulation, homeowners may be required to add at least 1 parking space for one bedroom ADUs and 2 spaces for two bedroom ones.

The design of the ADU is also relevant to the City of Coronado and they require the overall look and feel to match the existing residence. In addition, the build quality and materials must also match the primary residence. And, if you are looking to build a 2-story ADU your only option is to build it on top of the existing dwelling. A detached or ADU additions cannot exceed 16' in the City of Coronado.

It may sound like there are a lot of rules and restrictions for building an ADU in Coronado and in some ways you are correct. With that being said, Coronado does adhere to guidelines from the State of California and these laws and regulations are ever-changing and can differ in Coronado due to the Coastal Commission. You can use this blog as a general reference for ADU information but I always recommend consulting with a local architect or builder for up to date information on Coronado's current ADU building codes. Additionally, you can contact the City of Coronado directly via city hall.

Accessory Dwelling Units are a relatively new option for Coronado homeowners and many have already taken advantage of this opportunity to build an additional space on their property. And, there are numerous homeowners who will take advantage of this in the future. As discussed in my previous blog regarding zoning in Coronado, lot size still makes the biggest difference in development options for homeowners. The larger the lot, the more development opportunity you have for an ADU. This is mostly because of the additional parking requirement within the City of Coronado. Simply put, many homes do not have enough space to construct a detached ADU in Coronado.

If you are in the market to purchase a new home in Coronado and have a desire to build an ADU in the future, it is important to carefully survey the property with Coronado's current guidelines and regulations in mind. Bringing in professional consultation is also recommended to help you identify future development opportunities for an ADU.

Whether you are looking for more space, income potential or a great return on investment, building an ADU in Coronado can be an extremely smart and rewarding process. Feel free to contact me directly for more information and insights.

If you are looking to purchase or sell your home in Coronado, contact me today at 619-972-7364 or via email at

I would love to be a part of your 92118 story!

- Remi

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