Building an accessory dwelling unit (ADU) in Sacramento is one of the smartest investments for any homeowner in California. You can build ADUs for various purposes, from backyard homes to in-law suites, but that is not their only benefit. With an ADU, you are also looking at better property value, multi-generational housing options, and a way to generate passive rental income.

However, Sacramento has specific regulations for these units, which means you cannot build them on a whim. For those interested in ADU building in Sacramento, working with experienced builders like Good Life Construction can make the process much easier. Here is a clear guide on these regulations to help you plan your project accordingly. Understanding these rules from the start can save you time, money, and frustration. The sections below cover everything from size limits to specific requirements for kitchens and bathrooms.

Basic ADU Requirements

For any ADU building in Sacramento, it must meet the following general requirements:

• A single-unit, multi-unit, or duplex dwelling must be constructed before or at the time of building the ADU on the same lot.
• Up to two ADUs can be built on the lot.
• The ADU cannot be sold or presented for sale separately from the primary residence.
• The ADU can only be viable when it is built as
  • An extension of the primary residence
  • A new structure in your backyard, or on top of your residence or garage
  • A conversion of your existing garage
  • A conversion of a part of your primary residence

Sizing Requirements

When building ADUs, one of the most important considerations is their sizing limitations. The City of Sacramento has strict building code requirements that dictate the maximum size for ADUs, and knowing them beforehand is vital for a legally compliant construction.

• The maximum allowed size for an ADU is 1,200 square feet. If you are building two detached ADUs, their total square footage cannot exceed this number (excluding garages).
• Attached ADUs can be 50% of the primary residence’s size, or a maximum of 850 square feet, if it has one bedroom or less. However, if it has more than one bedroom, it can go up to 1,000 square feet.
• The height limit for a single-story ADU is 16 feet, which can also be pushed to anywhere between 18 and 25 feet for second-story constructions.

What Does Not Count as an ADU

Not every type of property or dwelling unit is considered an ADU in Sacramento. For starters, detached guest houses or similar properties with occasionally used areas and without cooking facilities cannot be regarded as ADUs.

Similarly, secondary dwelling units (SDUs), such as garage apartments, are not legally considered ADUs. While they may look similar, SDUs do not follow the same size limitations as per local regulations.

Homes on wheels, including tiny houses, are not considered ADUs either. As per Sacramento County rules, if you have a temporary living quarter regulated by the California Department of Motor Vehicles (such as a housecar or a recreational vehicle), it cannot be used as an ADU. Such homes can only be accepted as a dwelling unit if parked at a recognized mobile home park.

Additional Rules to Remember

As you plan your ADU construction, here are a few additional regulations it must follow:

1. Kitchen Requirements

Every ADU must include at least a basic kitchen with a stove or cooktop and an oven. According to the California Department of Housing and Community Development, ADUs must meet specific state standards for habitable spaces. JADUs (junior ADUs that are under 500 square feet) must have an efficient kitchen or better.

2. Bathroom Requirements

Both attached and detached ADUs must have separate bathrooms from the primary residence. If you are building a JADU, you can still include a common bathroom with the primary residence. However, it should also have a separate entrance from the residence and an interior entry into its main living area for shared access.

3. Fire Sprinkler Requirements

• Detached ADUs are exempt from Sacramento’s fire sprinkler requirements if the primary residence is not sprinklered and the ADU (excluding the garage) is within 1,200 square feet.
• Attached ADUs are exempt if the primary residence lacks sprinklers, the ADU is 50% or less of the residence area, and the total property size is within 3,600 square feet.

4. Project-Specific Requirements

• Single-family or halfplex projects can have up to three ADUs: one new detached ADU, one JADU, and one new attached ADU/attached conversion ADU/detached conversion ADU.
• Multi-family projects can have up to two newly constructed detached ADUs.

Conclusion

Building an ADU without knowing the local regulations can create a major headache down the road. If you are looking at a potential ADU project, use this guide to ensure that it is compliant with Sacramento’s regulations and leads to a smooth construction process. Working with an experienced contractor can also help you avoid common pitfalls and stay on track.