Do Accessory Dwelling Units (ADUs) in Los Angeles Fall Under Rent Control? Complete Guide for 2025

Los Angeles has aggressively promoted Accessory Dwelling Units (ADUs) — including backyard homes, garage conversions, and granny flats — as a critical solution to California's housing shortage. However, many property owners discover too late that adding an ADU can trigger complex rent control regulations under the Rent Stabilization Ordinance (RSO). Understanding these rules is essential before building or renting any ADU in Los Angeles.

What Are ADUs and Why Does Los Angeles Promote Them?

Accessory Dwelling Units are secondary housing units built on single-family residential lots. Common types include detached backyard cottages, converted garages, basement apartments, and additions above garages. Los Angeles streamlined ADU permitting to increase housing density and provide affordable rental options while allowing homeowners to generate additional income.

How Los Angeles Rent Control Works with ADUs

The relationship between ADUs and rent control depends on three key factors: the construction date of your main house, the type of ADU you build, and whether your property becomes multi-family housing.

Detached ADUs: Generally Exempt But With Major Exceptions

New detached ADUs are typically exempt from RSO rent caps, meaning you can set market-rate rent and increase it annually without RSO limitations. However, this exemption comes with a significant catch that surprises many property owners.

Critical Rule: If your main house was built before October 1, 1978, adding any ADU can trigger RSO coverage for the entire property, including the main house. This happens because your single-family home becomes a multi-family property once you add a rental unit.

Attached and Converted ADUs: More Likely Subject to Rent Control

Attached ADUs connected to pre-1978 homes often fall under RSO regulations. While Costa-Hawkins Act (California state law) may exempt new construction from rent caps, the main house typically becomes subject to RSO rules.

Converted ADUs — such as garage-to-apartment conversions or basement units — in pre-1978 properties are generally fully covered by the RSO, including both rent caps and just cause eviction protections.

Real-World Examples: How ADU Rent Control Applies

Example 1: A homeowner owns a 1965 single-family home in Silver Lake. They build a detached ADU in 2024. Result: The new ADU is exempt from rent caps, but the 1965 main house now falls under RSO rent control because the property became multi-family housing.

Example 2: A property owner converts their garage in a 1972 home into a studio apartment. Result: Both the main house and converted garage unit are subject to RSO rent control and just cause eviction rules.

Example 3: A homeowner builds an ADU on a property with a main house built in 1985. Result: Neither unit falls under RSO rent caps because the main house was built after the October 1, 1978 cutoff date.

Just Cause Ordinance: Eviction Rules Apply Regardless

Even if your ADU is exempt from rent control, both the main house and ADU tenants receive protection under Los Angeles's Just Cause Ordinance (JCO). This means you cannot evict tenants without specific legal reasons, such as non-payment of rent, lease violations, or owner move-in situations.

Common Mistakes Property Owners Make

Many Los Angeles property owners unknowingly trigger rent control by:

• Building ADUs without understanding how it affects their main house

• Assuming all new construction is exempt from rent control

• Not consulting with the Los Angeles Housing Department before construction

• Failing to register rent-controlled properties as required

Frequently Asked Questions About ADU Rent Control

Can I avoid rent control by not renting out my ADU? Yes, if you don't rent either unit, RSO rules don't apply. However, unused ADUs don't generate rental income.

Does Costa-Hawkins protect my new ADU from rent control? Costa-Hawkins may exempt new ADU construction from rent caps, but it doesn't prevent your main house from becoming rent-controlled.

What if I only rent the ADU and live in the main house? Your main house isn't subject to RSO if you live there, but the ADU may still fall under rent control depending on construction type and date.

Before Building: Essential Steps for ADU Planning

1. Check your main house construction date using Los Angeles County records

2. Consult the Los Angeles Housing Department about potential RSO implications

3. Review your financial projections considering potential rent control limitations

4. Consider legal consultation for complex situations involving multiple units or commercial properties

Professional Guidance Recommended

ADU rent control rules involve complex interactions between local ordinances, state law, and federal regulations. The Los Angeles Housing Department provides official guidance, but property owners often benefit from consulting real estate attorneys familiar with RSO regulations before beginning construction.

Understanding these regulations upfront helps property owners make informed decisions about ADU development while avoiding costly surprises that could affect long-term rental income and property management strategies.