Amador County
Unincorporated Amador County ADU rules
Research summary of what we found for Unincorporated Amador County in Amador County. Not a determination for a specific lot.
City or county ADU page
Unincorporated Amador County ADU page
Check any California address for freeHow big can an ADU be in Amador County?
Maximum size
A detached, new ADU up to 1,200 sq ft and 25 ft tall needs no parking (Category 2, Type 2). Under a Category 1 permit, which needs one parking space, an ADU may be as large as the main home's floor area. If the main home is under 1,000 sq ft, the Category 1 limit is 850 sq ft for an ADU with fewer than two bedrooms and 1,000 sq ft for two or more. An ADU inside existing space may add up to 150 sq ft to an accessory structure, for entry and exit only. The minimum size is an efficiency unit.
Source: Amador County Ordinance 1879 (adopted July 28, 2026), amending County Code Section 19.72.050, § 19.72.050(B)(2), (D)(1)(a), (D)(2)(a), accessed 2026-11-03.
ADU setbacks in Amador County
Setbacks
New ADU structures need 4 ft side and rear setbacks in areas where the County's State Responsibility Area fire safe rules (Chapter 15.30) do not apply. Inside those fire areas, Chapter 15.30 governs, and the ADU section does not state a figure. An ADU inside existing space may have smaller side and rear setbacks if the County finds them sufficient for fire safety.
Source: Amador County Ordinance 1879 (adopted July 28, 2026), amending County Code Section 19.72.050, § 19.72.050(A)(6), (D)(1)(c), accessed 2026-11-03.
What we found for Amador County
What we have for this place. Where a local figure is stricter than the California state baseline, both are shown.
Local ADU rules
The County's ADU and JADU rules are in County Code Chapter 19.72. Section 19.72.050 was rewritten by Ordinance 1879, adopted July 28, 2026 and in effect 30 days later. That change is not yet in the online County Code, so this page follows the adopted ordinance. ADU and JADU building permits in residential and mixed use zones are reviewed ministerially, without a hearing. Every ADU must meet the general rules and either the Category 1 or the Category 2 rules.
Source: Amador County Ordinance 1879 (adopted July 28, 2026), amending County Code Section 19.72.050, § 19.72.050 (introduction); Section III, accessed 2026-11-03.
ADU types and how many
On a lot with a single-family home: one ADU and one JADU, plus one detached, new ADU with 4 ft side and rear setbacks (outside State Responsibility Area fire areas). On a lot with an existing multifamily building: ADUs in non-livable space (storage rooms, attics, basements, garages) up to 25% of the existing units, plus detached ADUs up to the lesser of eight or the number of existing units. A planned multifamily building may have up to two detached ADUs.
Source: Amador County Ordinance 1879 (adopted July 28, 2026), amending County Code Section 19.72.050, § 19.72.050(B)(1), (C), (D)(3)-(4), accessed 2026-11-03.
Height
A detached, new ADU may be up to 25 ft tall (Category 2, Type 2), and so may detached ADUs on a lot with an existing multifamily building. The building code may not stop an ADU up to 25 ft tall when all other code rules are met.
Source: Amador County Ordinance 1879 (adopted July 28, 2026), amending County Code Section 19.72.050, § 19.72.050(A)(2), (D)(2)(b), (D)(4), accessed 2026-11-03.
Parking
Category 2 permits, including a detached, new ADU up to 1,200 sq ft and 25 ft tall, need no off-street parking. A Category 1 permit needs one added off-street space, which may be tandem on a driveway and may sit in a setback area unless the County finds that unsafe or unworkable for the site. No space is needed within a half mile walk of public transit, in a historic district, for an ADU inside the home or an existing accessory structure, within one block of a car share vehicle, or when the ADU is applied for together with a new home on the lot. Parking lost when a garage or carport is converted does not have to be replaced.
Source: Amador County Ordinance 1879 (adopted July 28, 2026), amending County Code Section 19.72.050, § 19.72.050(B)(3), (C), accessed 2026-11-03.
Junior ADUs
One JADU is allowed with one ADU on a lot with a single-family home, and a detached, new ADU may be combined with a JADU. The code points to state law (Gov. Code §§ 66333 to 66339) for JADU rules; under state law a JADU is up to 500 sq ft and inside the home. The County's general rules on water, septic, sprinklers and occupancy also apply to JADUs.
Source: Amador County Ordinance 1879 (adopted July 28, 2026), amending County Code Section 19.72.050, § 19.72.050(A), (B)(1), (D)(1)(d), (D)(2), accessed 2026-11-03.
Water, septic, sprinklers and rental
A well must meet County Code Section 14.06.055, and Environmental Health must confirm there is enough water and waste water service; a septic system needs Environmental Health sign-off. The ADU or JADU cannot be occupied before the main home. Fire sprinklers are needed only if the main home needs them, and an ADU does not trigger sprinklers in the main home. RVs, park models, yurts, tents, cargo containers and other movable units that do not meet the building code cannot be used as an ADU or JADU. ADUs must be rented for more than 30 days.
Source: Amador County Ordinance 1879 (adopted July 28, 2026), amending County Code Section 19.72.050, § 19.72.050(A)(2)-(5), (B), (C), accessed 2026-11-03.
Older unpermitted units
The County may not deny a permit to bring an ADU or JADU built without permits before January 1, 2020 up to code. Fees follow the fee schedule in place when you apply, without penalties for the unpermitted work. You may first get a confidential code inspection from a licensed contractor.
Source: Amador County Ordinance 1879 (adopted July 28, 2026), amending County Code Section 19.72.050, § 19.72.050(E), accessed 2026-11-03.
State housing department (HCD) review
On April 28, 2026, HCD found that the County's February 2026 ADU ordinance (Ordinance 1870) did not comply with state ADU law on five points: height, fire sprinklers, unit allowances, parking and unpermitted units. The County had until May 27, 2026 to respond. On July 28, 2026, it adopted Ordinance 1879, which raises the height limit to 25 ft and rewrites the sprinkler, unit allowance, parking and unpermitted unit rules. Confirm the current rules with the County of Amador.
Source: HCD ordinance review letter, County of Amador, Letter of April 28, 2026, accessed 2026-11-03.
California state rules
The statewide baseline recorded from state law and the HCD ADU Handbook.
Detached size cap described in state law
1,200 sq ft. 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. 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, 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, 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. 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. 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. 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. What we have 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.
Starting January 1, 2027: two detached ADUs
Starting January 1, 2027, AB 956 (Chapter 791, Statutes of 2026) raises from one to two the number of new detached ADUs a city or county must allow, without discretionary review, on a lot with a proposed or existing single-family home (Gov. Code 66323(a)). Each may be held to 800 sq ft, 4 ft side and rear setbacks and the state height limits. The city or county does not have to also allow a JADU on a lot where two new detached ADUs have been built. AB 956 also makes HOA and deed rules that effectively prohibit or unreasonably restrict an ADU or JADU void on any lot zoned to allow a single-family home, not only lots zoned for single-family use (Civil Code 4751 and 714.3).
Source: AB 956 (2025-2026), Chapter 791, Statutes of 2026, Gov. Code 66323; Civil Code 714.3, 4751; signed September 29, 2026, accessed 2026-11-03.
Starting January 1, 2027: impact fees above 750 sq ft
No impact fee may be charged on an ADU of 750 sq ft or less, or a JADU of 500 sq ft or less (Gov. Code 66311.5(c)). Starting January 1, 2027, SB 1117 (Chapter 809, Statutes of 2026) changes how fees are figured for larger ADUs: for up to two ADUs on a lot, the proportional impact fee is charged only on the interior livable space above 750 sq ft. On a lot with more than two ADUs, the fee stays proportional to the whole ADU. Utility connection fees and capacity charges are not changed.
Source: SB 1117 (2025-2026), Chapter 809, Statutes of 2026, Gov. Code 66311.5(c); signed September 29, 2026, accessed 2026-11-03.
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ADU rules near Amador County
Can I build an ADU in Unincorporated Amador County?
State law sets a baseline for ADUs in Unincorporated Amador County, and what we found locally is 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 the County of Amador planning department, or run a free address summary.
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