Is building an ADU a good investment in Downey?

Downey is actively broadening its housing options by authorizing the construction of Accessory Dwelling Units (ADUs). These small secondary units, allowed on single-family lots, present a practical solution for those in search of more affordable housing. Given the median monthly rent of $36.00 per square foot, the development of ADUs in Downey is yielding homeowners annual returns on investment surpassing 12%. 

Downey Accessory Dwelling Unit Requirements.

ADU permits are rapidly increasing in Downey. Here is a breakdown of ADU requirements in Downey for 2024.

General ADU requirements

Detached, attached, and conversion ADU types, along with JADU’s are all allowed in Downey. Both, single and two-story ADU’s are permitted.

For independent living your ADU must be equipped with: Exterior access separate from primary residence, Living, Sleeping, Dining, Cooking, and Bathing.

The kitchen must have at minimum the following: A sink, a refrigerator, a cooktop or range and cabinetry.

JADU can share a bathroom with the primary residence. However, JADU’s must have their own separate entrance.

Zoning

All zones single-family and multi-family most probably are eligible for ADU’s.

Number of Units

  • One ADU + One JADU in lots zoned single-family
  • For lots zoned multi-family, up to two detached ADU’s.
  • in multi-family, conversion units cannot be more than 25% of original number of units.

Building Size

  • JADU, maximum 500 SF
  • 150 SF Minimum for ADU’s and JADU’s.
  • 850 SF maximum for detached and attached ADUs

Building Height

  • 15 feet general height limit for detached ADUs
  • Attached ADU’s follow local zoning height limit.

Setbacks

Minimum setbacks:

  • 4 feet side and rear yard setbacks
  • 10 feet separation from existing structure.

Parking

Separate parking shall not be required for an ADU. However, the square footage of an ADU shall be included in the total square footage calculation to determine total parking required pursuant to Municipal Code Section 9708. Access to all on-site parking shall be provided from one (1) common driveway. This shall not preclude a circular driveway as allowed under Municipal Code Section 9710 – Residential Parking Design Standards

Fees

The exact number of fees depends on the zoning of your lot and the overall scope of your ADU project. This is a list of some of the typical fees you can expect to pay.

  • Plan Check fees
  • City Impact Fees
  • School Impact Fees
  • Building Code and Green Code Fees
  • Permit Fees
  • Utility Connection fees

Sprinkler System

When a fire sprinkler is not required for the primary residence, they are not required for your ADU or JADU.

Basements

You can convert an existing unfinished basement space to an attached ADU.

Owner Occupancy

Owner occupancy is not a requirement for permitting an ADU. Owners are required to live on the property only if a JADU has been constructed on it. This is a state law requirement.

Taxes

Building an ADU does not trigger a reassessment of the value of the primary residence. However property taxes are based on property values and an ADU does increase the value of the property.

Rental Limitations

Short-term rentals under 30 days are not allowed Downey.