top of page
  • Writer's pictureAEC Moreno Corp


Updated: Nov 19, 2020

In our previous blog post we talked about what an accessory dwelling unit is, giving basic references for understanding this process which can bring many benefits to homeowners.

But if you have not read our previous post, we will explain to you, accessory dwelling units, or ADU for short, are housing areas that are located on the same land as a single-family home. These homes can be detached from the main property, attached to them, or it can be a modification to the existing garage (if you have a garage) and typically, the owners will build these homes to provide income opportunities. Other times, people build ADUs for family reasons, often to care for their loved ones while still having a sense of independence for both parties.

Now more than ever we are living in the midst of a deep housing shortage that is increasing rents and property values ​​across the state, California officials and real estate experts are looking for a form of housing that is often passed overlooked as a possible solution, which, regularly this living space is separated from the main living unit.


The ADU's requirements in state law allow homeowners in single-family neighborhoods to build an accessory dwelling unit as long as they have the required space on their property. How much space? A separate ADU must be at least 10 feet from the primary residence and 5 feet from any property lines.

There is a limit per lot which must not exceed 3 units (this as mentioned above) one junior and one individual per residential lot divided into zones for single-family residences with a single-family residence already built on the lot (triplex).

An ADU should have its own separate entrance, a kitchen which should be equipped with a sink, kitchen equipment, counter top and storage cabinets.

You must have fire sprinklers, fire alarms, and ADU's will not be required to provide fire sprinklers if they are not a requirement for the primary residence.

Cities must approve an ADU within 60 days, without a hearing or discretionary review, and must have a minimum living space of 150 square feet.

The city is required to approve any attached or detached ADU's of less than 1200 square feet, unless the city adopts a new ADU ordinance that sets local government standards for a zoned single-family lot.

A conversion ADU can be up to 1,200 square feet regardless of the size of the parcel or house, as well as it can be expanded up to 150 square feet, not to exceed 1,200 square feet in total, except when necessary to accommodate entry. and departure to the ADU.

A conversion ADU can be created from a legal structure built at any time (referring to garage, accessory structure, storage room) and has sufficient fire safety setbacks per local ordinance.

Indoor connection between ADU and main unit, referring to laundry room, is allowed.

The height limit for a single deck ADU is 16 feet with 4 feet side and rear setback.

The height limit and setback requirements for a double-deck ADU depend on local ordinance.

ADUs of 750 square feet or less are not subject to impact fees (schools, parks, water). Rates for ADUs over 750 square feet are limited and determined based on the square footage of the primary residence.

Up to 2 newly constructed ADUs are allowed (either attached or detached), and up to the amount that equates to 25% of existing housing units can be added by converting non-habitable space within existing multi-family buildings with a set of 4 feet and rear setback and maximum height of 16 stories.

Local governments must provide an exception to zoning and land use regulations that include an ADU ordinance for people with disabilities. Possible exceptions are not limited and may include developmental standards such as delays and parking requirements and permitted uses that promote housing opportunities for people with disabilities.

The owners who are just looking for some extra room probably don’t need to bother getting all the necessary permits to build an ADU—most photo labs and fitness rooms don’t need a separate kitchen.

A standard addition permit may be an easier way to add that flex space.

361 views0 comments

Related Posts

See All


bottom of page