Alameda County

Livermore ADU rules

Research summary of local ADU rules on file for Livermore in Alameda County. Not a determination for a specific lot.

Last checked October 23, 2026.

City or county ADU page

Livermore rules on file

Local rules recorded in this project for this jurisdiction. Where a city figure on file is stricter than the state baseline on file, both are shown.

Detached ADU size
Up to 850 sq ft with one bedroom or fewer, or 1,000 sq ft with more than one bedroom. Minimum 150 sq ft (or the efficiency unit minimum).
Source: City of Livermore ADU Submittal Packet (Development Code Chapter 11.30), 11.30.060 A–B, accessed 2026-10-23.

Attached ADU size
Up to 50% of the main home's floor area (not counting attached garages), but never less than 850 sq ft (one bedroom or fewer) or 1,000 sq ft (more than one bedroom).
Source: City of Livermore ADU Submittal Packet (Development Code Chapter 11.30), 11.30.060 B.2, accessed 2026-10-23.

Conversion ADU size
No size cap for an ADU converted from space inside an existing or proposed home or accessory structure; it may add up to 150 sq ft for entry and exit.
Source: City of Livermore ADU Submittal Packet (Development Code Chapter 11.30), 11.30.060 B.3, accessed 2026-10-23.

Side and rear setbacks
4 feet minimum from side, rear and street-side lines for attached and detached ADUs. Conversions need no new setbacks if they meet fire and safety codes.
Source: City of Livermore ADU Submittal Packet (Development Code Chapter 11.30), 11.30.060 C, accessed 2026-10-23.

Distance from other buildings
A detached ADU must be at least 5 feet from all structures on the lot, except that it may attach to a detached garage or other accessory structure, or as the building code requires.
Source: City of Livermore ADU Submittal Packet (Development Code Chapter 11.30), 11.30.060 D, accessed 2026-10-23.

Detached ADU height
16 feet, plus 2 feet to match the main home's roof pitch. 18 feet (plus 2 feet for roof pitch) within a half mile walk of a major transit stop or high-quality transit corridor, and 18 feet on a lot with a multistory multifamily building.
Source: City of Livermore ADU Submittal Packet (Development Code Chapter 11.30), 11.30.060 E.1, accessed 2026-10-23.

Attached ADU height
25 feet or the main home's height limit, whichever is lower.
Source: City of Livermore ADU Submittal Packet (Development Code Chapter 11.30), 11.30.060 E.2, accessed 2026-10-23.

Parking
One off-street space for each attached or detached ADU, which may be tandem. None is required near transit, in a historic overlay or for a listed historic resource, where on-street permits are required but not offered, or within a block of car share. Converted or removed garage parking does not have to be replaced. Junior ADUs need no space.
Source: City of Livermore ADU Submittal Packet (Development Code Chapter 11.30), 11.30.060 H; 11.30.090 I, accessed 2026-10-23.

Design rules for ADUs under the City code
Separate exterior entrance; a detached ADU's entrance may not face the street, and an attached or conversion ADU's entrance may not be on the main home's front. New stairs must be enclosed. No new balconies, roof decks or decks more than 2 feet above grade. Roof, siding and color must match the main home.
Source: City of Livermore ADU Submittal Packet (Development Code Chapter 11.30), 11.30.070 A–D, accessed 2026-10-23.

Review time
A complete ADU or junior ADU application is decided within 60 days. A detached ADU using a City “pre-approved” plan (or a plan identical to one the City accepted) in the current building code cycle is decided within 30 days.
Source: City of Livermore ADU Submittal Packet (Development Code Chapter 11.30), 11.30.090, accessed 2026-10-23.

City “pre-approved” plans
Applications using a “pre-approved” plan are reviewed in 7 business days instead of 15, with a flat City plan review fee. You contract with the plan's designer, and site-specific plans, studies and engineering are still required.
Source: City of Livermore, “Pre-Approved” Accessory Dwelling Unit page, For Homeowners, accessed 2026-10-23.

Submittal items
Include elevations and photos of all sides of the existing home showing the ADU matches it, a title report no more than 6 months old, and a Zone 7 impervious surface worksheet, along with the other items in the packet.
Source: City of Livermore ADU Submittal Packet (Development Code Chapter 11.30), Submittal checklist, accessed 2026-10-23.

Impact fees
No impact fee for an ADU under 750 sq ft or any junior ADU. Larger ADUs pay fees in proportion to the main home's size.
Source: City of Livermore ADU Submittal Packet (Development Code Chapter 11.30), 11.30.100, accessed 2026-10-23.

Who to contact
Planning Division 925-960-4450; Building (Permit Center) 925-960-4410.
Source: City of Livermore, “Pre-Approved” Accessory Dwelling Unit page, “Pre-approved” ADU Plans, accessed 2026-10-23.

California state rules on file

The statewide baseline recorded from state law and the HCD ADU Handbook.

Detached size cap described in state law
1,200 sq ft. Recorded in this rules file from Government Code section 66314.
Source: California Government Code section 66314, 66314, accessed 2026-10-16.

Side and rear setback cap for a new ADU
4 ft. Recorded in this rules file from Government Code section 66314, which describes a cap on side and rear setbacks for a new ADU.
Source: California Government Code section 66314, 66314, accessed 2026-10-16.

Setback for a conversion of an existing structure
No additional setback, as recorded in this rules file from Government Code section 66314 for a conversion of an existing structure.
Source: California Government Code section 66314, 66314, accessed 2026-10-16.

Minimum lot size
A city may not impose a minimum lot size for an ADU, as recorded in this rules file from Government Code section 66314.
Source: California Government Code section 66314, 66314, accessed 2026-10-16.

Minimum unit the handbook says cities must allow
At least an 800 sq ft ADU with 4 ft side and rear setbacks. The HCD ADU Handbook (updated March 2026) describes this under section 66321(b)(3).
Source: HCD ADU Handbook, 66321(b)(3); handbook updated March 2026, accessed 2026-10-16.

Detached height described in the handbook
16 ft, or 18 ft or 20 ft in some cases. The HCD ADU Handbook (updated March 2026) describes this under section 66321(b)(4).
Source: HCD ADU Handbook, 66321(b)(4); handbook updated March 2026, accessed 2026-10-16.

Permit decision deadline
60 days. Recorded in this rules file from Government Code section 66317(a)(3): the permitting agency must decide on (approve or deny) a completed ADU application within 60 days when an existing single-family or multifamily dwelling is on the lot. Section 66317(a)(1) says the application is considered ministerially, without discretionary review or a hearing.
Source: California Government Code section 66317, 66317(a)(1), (a)(3), accessed 2026-10-17.

Owner-occupancy requirement
None. Recorded in this rules file from Government Code section 66315: a local agency may not impose an owner-occupancy requirement on an ADU. It may require that the property be used for rentals of terms 30 days or longer. The HCD ADU Handbook (updated March 2026) describes the same rule.
Source: California Government Code section 66315, 66315; HCD ADU Handbook updated March 2026, accessed 2026-10-17.

Parking near public transit
No parking standards within one-half mile walking distance of public transit. Recorded in this rules file from Government Code section 66322(a)(1). Section 66322(a) lists several other cases where parking standards may not be imposed.
Source: California Government Code section 66322, 66322(a), accessed 2026-10-17.

Ministerial categories
The HCD ADU Handbook (updated March 2026) states that Government Code section 66323 sets four ministerial categories. This rules file does not restate those four categories.
Source: HCD ADU Handbook, 66323; handbook updated March 2026, accessed 2026-10-16.

Fire Hazard Severity Zones
If your lot is in a Fire Hazard Severity Zone, the CAL FIRE Office of the State Fire Marshal says in Information Bulletin 25-004 (issued March 3, 2025): “Fire Hazard Severity Zones (FHSZs) should not restrict the development of Accessory Dwelling Units (ADUs). However, additional building standards may be necessary, including but not limited to California Fire Code Chapter 49 and California Building Code Chapter 7A.” State ADU law does not itself bar an ADU there. A city or county may still apply its building code, including wildfire-resistant construction (Gov. Code 66314(d)(8)); require side and rear setbacks “sufficient for fire and safety” for a unit converted under 66323(a)(1); and decline parking in setbacks on specific fire and life safety findings (66314(d)(10)(B)). It may also consider public safety when it designates where ADUs may be permitted (66314(a)). Sprinklers can't be required in an ADU or JADU if the primary residence doesn't need them (66314(d)(12), 66323(d)). Some cities and counties still apply their own fire-zone limits. Where this summary has one, it is listed with the local rules. This summary does not look up your lot. Check the CAL FIRE Fire Hazard Severity Zone map viewer linked from the State Fire Marshal's Fire Hazard Severity Zones page: https://experience.arcgis.com/experience/5065c998b4b0462f9ec3c6c226c610a9
Source: CAL FIRE Office of the State Fire Marshal Information Bulletin 25-004, page 4, issued March 3, 2025; Gov. Code 66314, 66323, accessed 2026-10-20.

State baseline on the directory → · State ADU rules on the homepage →

Can I build an ADU in Livermore?

State law sets a baseline for ADUs in Livermore, and the local standards on file are listed on this page. Whether a specific lot can add an ADU depends on zoning, utilities, and other site facts this page does not measure. Confirm with City of Livermore Planning Division, or run a free address summary.

Check any California address for free