Coronado, CA Accessory Dwelling Unit Regulations

Introduction to Accessory Dwelling Units

An accessory dwelling unit commonly called a granny flat or in-law suite must exist on a lot that’s zoned single-family. It has its own entrance, separate from the primary house, as well as a kitchen, bathroom and living space. These units can be rented, year-round, and add a lot of value to a property.

Accessory dwelling units take different structural forms. They can be garage conversions, stand-alone units, attic or basement conversions, or be attached to the main house.

Zoning in Coronado, CA

Only one ADU is allowed per single family lot. ADUs are allowed in residential zones which already have one single-family dwelling.

Lot size in Coronado

ADUs are not allowed on lots that do not have a minimum of 25 feet of frontage on a street.

Min/Max Building Sizes

The floor area of the ADU should not be more than 50% of the existing residence or 800 square feet (whichever is less).

Height Restrictions

Refer to local building code.


  1. A minimum of one parking space is required for each ADU. There should be one parking space for each bedroom.
  2. The primary residence must meet the parking requirement for single-family dwellings before construction of an ADU may begin.
  3. Parking must its if demolished or removed during ADU construction.
  4. Replacement parking may be open and unenclosed or covered and enclosed, or tandem, but it may not be within the front yard setback area.


Refer to local building code.

Owner Occupancy

The owner must occupy either the main residence or the ADU.


California passed Senate Bill 1069 in an effort to increase the supply of housing to the state. For this reason, any accessory dwelling unit may be used for a long-term rental. ADUs must be rented for six months or longer.

How to Evaluate ROI

Building an accessory dwelling unit, especially if you intend to keep the property for a few years, represents an enormously beneficial opportunity to maximize your property.

By constructing an accessory dwelling unit you are adding additional square footage to the property. So if you can build a unit for $250 a square foot, but the average value of homes in your neighborhood are worth $401 a square foot you are gaining instant equity through the project. Plus, you also now have the added benefit of a flexible space that can be rented or used for the family.

Additional notes

  • Carriage Houses are not allowed to be converted to an ADU.
  • Construction on a historically designated lot require


What are you waiting for?  Contact us today at 888-987-6638 or

Call Now Button