Number of ADUs Allowed in San Gabriel
- Maximum size: 1,200 sq ft (detached or attached, or 50% of the size of the main dwelling)
- Side/rear setbacks: 4 feet
- Two story: Yes, for both attached and detached ADUs
- Building separation: 6 feet
- Soils Report: Possibly, especially in areas with grading or on hillsides
- Building Verification Survey: Yes
- Coastal permit (in some areas): N/A
- Stormwater Mitigation: Yes
Number of ADUs Allowed in San Gabriel
You are allowed to put one attached or detached ADU on single-family property in San Gabriel, as well as one JADU.
Multifamily property owners in San Gabriel may convert existing uninhabitable space into at least one attached ADU, and additional ADUs not to exceed a maximum number equal to 25% of the existing units. Ergo:
- From 2 to 7 units, you could convert existing uninhabitable space into one ADU
- From 8 to 11 units up to 2 ADUs
- From 12 to 15 units up to 3 ADUs
- And so on.
No more than two detached ADUs may be constructed on a multifamily lot in San Gabriel.
ADU San Gabriel – Size & Building Constraints
A detached ADU can be up to 1,200 square feet in San Gabriel.
An attached ADU in San Gabriel can be up to 1,200 square feet, or 50% of the square footage of the primary dwelling unit, whichever is smaller.
An attached or detached ADU can be up to 16 feet tall in San Gabriel.
Due to the 16-foot height restriction, 2-story ADUs are generally not permitted in San Gabriel.
No, height restrictions on detached ADUs in San Gabriel generally prevent two ADUs from being stacked one on top of each other (one on each story of a two-story building). Single-family property also limits you to one detached ADU on the property, which would also eliminate the option of two stacked detached ADUs.
No specific policies restrict two ADUs from being attached to each other on one separate detached structure in San Gabriel. Keep in mind that only multifamily property is eligible, since multifamily property can have up to two detached ADUs and single-family property is limited to one detached ADU.
No, a JADU is defined as an ADU converted from existing space within the main structure of the primary dwelling unit. As such, it cannot be attached to an ADU.
Generally roof decks would be permitted on an ADU, but must meet the height restrictions for the zone. Roof decks cannot encroach into the required setbacks. As a rule of thumb, railings and access staircases above 42″ need to be included in height calculations.
An ADU must match or harmonize with the exterior of the main dwelling unit, including color palette, roof pitch, architectural style, and other aesthetic characteristics.
ADU Setbacks in San Gabriel
ADUs behind the primary dwelling unit in San Gabriel require a minimum of 4-foot side and rear setbacks.
An ADU must be a minimum of 6 feet from other structures on the property in San Gabriel.
An ADU may be permitted in the front yard of property in San Gabriel if it adheres to front yard setback requirements and if the ADU is limited to a maximum of 800 square feet.
ADU Setbacks in San Gabriel
No, you can submit plans and applications to the Community Development Department via email at the following address:[email protected]
San Gabriel may require a soils report for ADU permitting to make sure the soil can support the new structure, especially if the ADU will be located on a hillside, an area with significant grading, or if there are special foundation requirements.
Sufficient green space and permeable surface must be maintained on the property. City regulations do not specify specific percentages and must be approved on a case-by-case basis in the planning stage.
The plan check process for an ADU in San Gabriel involves the following steps:
- Submit plans to the Building & Safety Division
- Plan check
- Resubmittal to address change requests
- Permit issuance
- Inspection
The plan check usually takes about 4-6 weeks, while the permit issuance process can take up to an additional 2-3 weeks.
Parking for San Gabriel ADU
One new parking spot is typically required to be added to the lot per new ADU. However, exemptions may apply if:
- The ADU was built into an existing structure.
- The property is located within a historic district.
- The property is located within ½ mile walking distance of a public transportation stop.
- The property is located within one block of an established vehicle share stop.
- Off-street parking permits are required but not offered to ADU occupants.
If a parking space must be added, it can be included on the driveway or any setback areas, and it may be configured as tandem parking.
Additional Requirements in San Gabriel
Per Title 24 of the California Energy Code, solar panels of appropriate size and capacity are mandatory on new-construction ADUs. ADUs built from converted existing structures are exempt, as may be ADUs located under significant shading. Smaller ADUs may be subject to reduced or modified solar panel requirements.
An ADU is not required to have a separate water or electrical meter. You can opt for the ADU to share service with the main dwelling unit. However, you can request separate water or electrical meters from the City of San Gabriel.
An ADU doesn’t necessarily get its own address, but a separate address can be applied for and may be mandated if determined by the city to be necessary for public safety reasons.
Low Impact Development (LID) is an approach to land development or redevelopment that seeks to preserve and conserve onsite water quality and natural features, with minimal detrimental effect to local waterways and ecosystems. The City of San Gabriel may require LID fees for larger ADUs.
No, use of an ADU as an Airbnb or short-term rental is not allowed in San Gabriel.
Per the Costa-Hawkins Act of 1995, San Gabriel does not impose rent control on dwellings constructed after February 1, 1995. This means most new-build ADUs are exempt. However, if the primary dwelling unit is subject to rent control, it might apply to the ADU as well.
While encouraging the use of electric appliances for efficiency and sustainability, San Gabriel does not prohibit gas appliances in new ADUs as long as all relevant installation and safety standards are met.
In San Gabriel you are only required to install sprinklers in a new ADU if the primary dwelling unit has them as well. You may also be required to install them if the ADU is located within a special fire hazard zone.
Have Additional Questions?
Visit our comprehensive FAQ page for more information.