Altadena ADUs

Accessory Dwelling Units (ADUs) are one of the fastest growing and best capex investments in California

Multi-Family
Summary

Multi-family properties are allowed to add ADUs according to California's Government Code Section 65852.2.(e). SB 897 made changes to existing legislation providing for the increased development potential of multifamily buildings.

ADU Types

ADUs may be established on multifamily properties through the conversion of existing non-habitable spaces within the multifamily buildings or the construction of new detached units.

Property Eligibility

Properties that have at least two legally established residential dwelling units that are connected are eligible to develop ADUs under the multifamily standards.

Number Allowed

According to state law, multifamily properties are allowed 1 attached conversion ADU for each 4 existing units, OR they are allowed 2 detached ADUs (conversion or new construction) per multi-family property.

Unit Size

The maximum allowable floor area of an ADU on a multifamily property is 800 sf and the minimum allowable size of an ADU is 150 sf.

Max Height

A height of 16 feet for a detached accessory dwelling unit on a lot with an existing or proposed multifamily dwelling unit. If the property is located within ½ mile walking distance of a public transit station or the existing building is 2 stories, then the ADU is allowed to be 18 feet in height. Height limits do not apply to conversions of existing spaces to ADUs.

Parking

Required parking for the ADU may not exceed one space per bedroom. The ADU shall be exempt from parking requirements if located within ½ mile walking distance of a public transit station. When a garage, carport, or covered parking structure is demolished in conjunction with the construction of an accessory dwelling unit or converted to an accessory dwelling unit, the local agency shall not require that those off-street parking spaces be replaced. (Gov. Code, §65852.2, subd. (a)(1)(D)(xi). (pg. 17 link)

Setbacks

The minimum required setback for a new construction ADU on a multifamily property is 4 feet from the rear and interior side property lines. Setbacks do not apply to conversions of legally established structures converted into an ADU.

Fire Safety

The installation of fire sprinklers shall not be required in an accessory dwelling unit if sprinklers are not required for the primary residence. The construction of an accessory dwelling unit shall not trigger a requirement for fire sprinklers to be installed in the existing multifamily dwelling.

Permit Timeline

Ministerial approval process with a 60-day maximum review cycle.

Permit Fees

750sf ADUs are exempt from impact fees.

Rental Term

A local agency shall require that a rental of the accessory dwelling unit created pursuant to this subdivision be for a term longer than 30 days.

Existing Non-Conformities

A local agency shall not require, as a condition for ministerial approval of a permit application for the creation of an accessory dwelling unit, the correction of nonconforming zoning conditions.

RSO Exemption

Newly created ADUs, including conversions, are exempt from state and local Rent Stabilization Ordinances (RSO) for 15 years after the certificate of occupancy is issued. This includes buildings that otherwise are subject to the requirements of an RSO.

400 sf 0-bed 1-bath
20 ft x 20 ft

500 sf 2-bed 1-bath
25 ft x 20 ft

798 sf 2-bed 2-bath
38 ft x 21 ft

800 sf 3-bed 2-bath
40 ft x 20 ft

Last updated 09/13/23


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