How Do I Know If My Property Qualifies for an ADU?

Does Your Property Qualify for an ADU? Here Is How to Find Out

If you are a California homeowner thinking about building an Accessory Dwelling Unit (ADU), the very first question you need answered is whether your property actually qualifies. The good news is that California state law, specifically Assembly Bill 68 and Senate Bill 13, has dramatically expanded ADU eligibility across the state. But eligibility still depends on a range of property-specific factors, including zoning, lot size, setbacks, easements, and more.

This guide will walk you through every qualification requirement for building an ADU in California, with a special focus on Los Angeles. By the end, you will have a clear understanding of whether your property is ready for an ADU project, or what steps you need to take to make it happen.

Zoning Requirements for ADUs in California

Zoning is the first and most critical factor in determining whether your property qualifies for an ADU. Under California state law, ADUs are permitted on any lot that contains an existing or proposed single-family or multifamily dwelling. This applies to all residential zones, including R-1, R-2, R-3, and even some mixed-use zones.

What Zones Allow ADUs?

Thanks to California's progressive ADU legislation, the state has overridden many local zoning restrictions. Here is a breakdown of what is typically allowed:

For properties in the City of Los Angeles, you can check your zoning designation using the ZIMAS (Zoning Information and Map Access System) tool. Simply enter your address and you will see your property's zone, general plan designation, and any applicable overlays.

Specific Plan Areas and Overlays

Some properties fall within Specific Plan areas, Historic Preservation Overlay Zones (HPOZs), or Coastal Zones. While state law limits local jurisdictions from outright banning ADUs, properties in these areas may face additional design review requirements or height restrictions. If your property is in an HPOZ, for example, your ADU design may need to be architecturally compatible with the historic character of the neighborhood.

Lot Size Minimums and Maximums

One of the most significant changes in California's ADU laws is the elimination of lot size minimums for most ADU types. Under current state law, there is no minimum lot size required to build an ADU of up to 800 square feet, as long as the ADU meets setback requirements.

Lot Size Considerations by ADU Size

While the state has removed minimum lot size restrictions, your lot still needs to physically accommodate the ADU with the required setbacks. On a very small lot, you may find that after accounting for the main house, garage, and required setbacks, the buildable area is limited. A site assessment by an experienced ADU contractor can help you understand exactly what fits on your property.

Setback Rules for ADUs

Setbacks determine how far your ADU must be placed from property lines and existing structures. California state law has standardized many setback requirements to make ADU construction easier.

Standard ADU Setbacks Under California Law

• Rear setback: 4 feet minimum from the rear property line
• Side setback: 4 feet minimum from the side property line
• Front setback: Subject to local rules (typically matches the main dwelling)
• Height limit: Generally 16 feet for detached ADUs (up to 18 feet in some cases with a pitched roof)
• Separation from main dwelling: No minimum required by state law for detached ADUs

For a detailed breakdown of Los Angeles setback requirements, read our guide on ADU setbacks in Los Angeles.

When Setback Exceptions Apply

If you are converting an existing structure (like a garage) into an ADU, the existing setbacks are grandfathered in. This means a garage that sits on the property line can be converted to an ADU without needing to meet the 4-foot setback requirement. However, you generally cannot expand the structure footprint into the non-conforming setback area.

Owner-Occupancy Requirements

Owner-occupancy rules have been one of the most debated aspects of ADU regulation. Here is the current status:

California State Law (2026)

Under current California law, owner-occupancy requirements are not enforced for ADUs permitted between January 1, 2020 and January 1, 2025. For ADUs permitted after January 1, 2025, local jurisdictions may impose owner-occupancy requirements, but many cities have chosen not to.

In Los Angeles specifically, the city does not require owner-occupancy for most ADU types. This means you can rent out both the main house and the ADU, or live in either unit while renting the other.

JADU Owner-Occupancy

Junior ADUs (JADUs) are different. California law requires the property owner to occupy either the JADU or the primary residence. This requirement applies to all JADUs regardless of when they were permitted.

Easements and Right-of-Way Considerations

Easements are legal rights that allow others to use a portion of your property for specific purposes. Common easement types that can affect ADU construction include:

• Utility easements: Allow utility companies access to power lines, gas pipes, or sewer lines running through your property
• Access easements: Grant neighbors or the public the right to cross your property
• Drainage easements: Protect natural drainage patterns and stormwater flow
• View easements: Protect a neighbor's view corridors (more common in hillside areas)

You cannot build an ADU within an easement area. Before starting your project, review your property's title report or preliminary title search to identify any recorded easements. A title company can provide this information, or you can often find it on your original deed documents.

How Easements Affect ADU Placement

If your property has a 10-foot utility easement along the rear property line, your ADU must be set back at least 10 feet from that line (plus any additional setback requirements), rather than the standard 4-foot setback. This can significantly reduce your buildable area on smaller lots.

Utility Access Requirements

Your ADU needs access to water, sewer, electricity, and potentially gas. The availability and cost of utility connections can significantly impact your project feasibility.

Water and Sewer

For ADUs under 750 square feet, California law prohibits local agencies from requiring new water or sewer connections or charging connection fees. For larger ADUs, your local utility provider may require separate connections and charge applicable fees.

If your property is on a septic system rather than connected to municipal sewer, additional requirements may apply. The local health department will need to confirm that your septic system can handle the additional load from the ADU. Learn more in our guide on ADU septic system requirements.

Electrical Service

Most ADUs can be connected to your existing electrical panel with a sub-panel. However, if your main panel is outdated (particularly older 100-amp panels), you may need to upgrade to a 200-amp panel before adding an ADU. For more on this topic, check our guide on electrical requirements for ADUs.

Complete ADU Qualification Checklist

Use this comprehensive checklist to evaluate whether your property qualifies for an ADU. Check each item to see where you stand:

Special Situations That Affect Eligibility

Properties in Fire Hazard Severity Zones

If your property is in a Very High Fire Hazard Severity Zone (VHFHSZ), you can still build an ADU, but additional fire safety requirements apply. These may include fire-resistant roofing, tempered glass windows, ember-resistant vents, and defensible space around the ADU. The California Office of the State Fire Marshal provides detailed requirements for construction in fire hazard areas.

Properties with Unpermitted Structures

If your property has unpermitted additions or structures, you will typically need to address those before obtaining an ADU permit. Some cities offer amnesty programs or streamlined processes for legalizing existing unpermitted structures as part of an ADU project.

Properties in HOA Communities

Under California law (AB 68 and subsequent legislation), Homeowners Associations (HOAs) cannot prohibit ADU construction. While an HOA may impose reasonable design and aesthetic standards, they cannot unreasonably restrict or prevent ADU development. If your HOA is blocking your ADU project, consult with a real estate attorney familiar with California ADU law.

How to Verify Your Property's ADU Eligibility

Follow these steps to confirm your property qualifies:

1. Check your zoning: Use your city's online zoning tools (like ZIMAS for Los Angeles) to confirm your property is in a residential zone.
2. Review your property survey: Identify lot dimensions, setback lines, and any recorded easements.
3. Contact your local planning department: Ask about any specific plan overlays, historic designations, or other restrictions that may affect your project.
4. Check utility availability: Contact your water, sewer, and electric providers to confirm service availability and capacity.
5. Consult with an ADU specialist: An experienced ADU professional can evaluate your property and provide a feasibility assessment.

Common Reasons Properties Do Not Qualify (and Workarounds)

Even if one factor seems like a disqualifier, there are often creative solutions:

• Lot too small: Consider a JADU (up to 500 sq ft) within your existing home, which has no lot size minimum
• Easement in the way: Reposition the ADU to avoid the easement area, or explore whether the easement can be relocated
• Inadequate utility access: Budget for utility upgrades as part of your project costs
• Septic system limitations: Consider a JADU with shared facilities, or upgrade the septic system
• Hillside restrictions: Work with an engineer to design an ADU that meets hillside grading and geological requirements

Next Steps After Confirming Eligibility

Once you have confirmed your property qualifies, here is what to do next:

1. Get a property survey if you do not have a recent one. Learn more about when to order a survey.
2. Document existing conditions on your property. Our guide on documenting existing conditions covers everything you need.
3. Explore floor plan options that fit your lot and budget. Check out our ADU floor plan guide.
4. Get cost estimates from qualified contractors. Our ADU cost guide provides realistic budgeting information.
5. Schedule a consultation with an ADU specialist who can walk your property and provide personalized recommendations.

Conclusion

The vast majority of single-family residential properties in California qualify for some type of ADU. California's state laws have removed many of the traditional barriers, including lot size minimums, parking requirements, and owner-occupancy mandates. However, every property is unique, and factors like easements, utility access, topography, and existing structures can all affect what is possible on your specific lot.

The best way to know for certain whether your property qualifies is to conduct a thorough site evaluation. This includes reviewing zoning, pulling a title report, commissioning a property survey, and consulting with professionals who specialize in ADU design and construction. With the right team on your side, you can navigate these requirements efficiently and move forward with confidence.

Frequently Asked Questions: ADU Qualification Edge Cases

After helping hundreds of California homeowners evaluate their properties, we have compiled answers to the most common qualification questions that come up during the planning process. These edge cases often trip up first-time ADU builders, so understanding them early can save you time and money.

Can I build an ADU if I already have a detached garage or guest house?

Yes, in most cases. California law allows one ADU and one Junior ADU (JADU) on single-family lots. If your existing detached structure is not already permitted as a dwelling unit, you can still build a new ADU. You may also be able to convert that existing garage into a JADU while building a separate detached ADU. Talk to your local planning department to confirm what counts as an existing dwelling unit on your lot. For more on garage conversions, see our guide on garage conversion ADU FAQs.

What if my property has an unpermitted addition or structure?

Unpermitted structures can complicate your ADU application but do not necessarily disqualify your property. The city may require you to either remove, legalize, or address the unpermitted work before issuing ADU permits. In Los Angeles, the Department of Building and Safety may require a separate permit correction process. Working with an experienced ADU contractor who understands the legalization process is highly recommended.

Does my property qualify if it is on a hillside or steep slope?

Hillside properties can qualify for ADUs, but the process is more complex. You may need additional geotechnical reports, retaining wall engineering, and grading plans. Some hillside-specific setback requirements may apply. The costs for site preparation on hillside lots can be significantly higher, so budgeting carefully is essential. Review our article on hidden ADU costs for more on unexpected site preparation expenses.

Can I build an ADU on a lot with an existing accessory structure like a pool house?

A pool house that is not a permitted dwelling unit typically does not count against your ADU allowance. You can still build an ADU on the lot, provided you meet setback and lot coverage requirements. However, if the pool house already has a kitchen, bathroom, and sleeping area and was permitted as a habitable space, your city may classify it differently. Always verify with your planning department before assuming eligibility. For pool house conversion ideas, check out our article on pool house ADU options.

What happens if my lot has deed restrictions or CC&Rs that prohibit additional structures?

California law (AB 670 and AB 1033) explicitly prohibits HOAs and CC&Rs from unreasonably restricting ADU construction. If your homeowners association or deed restrictions attempt to block your ADU project, state law generally overrides those restrictions. However, reasonable architectural review requirements may still apply. If you encounter resistance, consulting with an attorney who specializes in California real estate law can help you understand your rights.

Is my property eligible if it sits in a fire hazard severity zone?

Properties in Very High Fire Hazard Severity Zones (VHFHSZ) can still qualify for ADUs, but additional fire safety requirements will apply. These may include fire-resistant building materials, enhanced sprinkler systems, defensible space around the structure, and fire-rated construction assemblies. Review our detailed guide on fire-rated separation requirements for ADUs for specifics on what your city may require.

Can I build an ADU if my primary home is a mobile or manufactured home?

Under current California law, ADUs are allowed on lots with existing or proposed residential dwellings. If your manufactured home is on a permanent foundation and is classified as a single-family residence by your local jurisdiction, you should be eligible. However, mobile homes on leased land in mobile home parks typically do not qualify. The key factor is whether your property is classified as a single-family residential lot with a permanent dwelling.

What if my property has environmental restrictions such as wetlands or protected habitat?

Environmental restrictions can affect where on your lot an ADU can be placed, but they do not automatically disqualify your property. If part of your lot includes wetlands, riparian buffers, or protected habitat, the buildable area may be reduced. You may need environmental impact assessments or additional agency approvals. Working with a designer who has experience navigating environmental constraints in your specific area will help you find the best path forward. Learn more about the pre-design process in our guide on documenting existing conditions before ADU design.