ADU Pass
Rancho Cucamonga
San Bernardino County portion
Also in: No County
ADU Pass helps homeowners in Rancho Cucamonga, San Bernardino County, California navigate the permit paperwork for building an accessory dwelling unit. This area covers 4 ZIP codes.
Map
ADU details
ADU legality: allowed
Rancho Cucamonga uses the Accela ACA ePlanRC portal (different from Ontario's custom Citizen Portal) and bypasses Planning entirely for ADU intake. Northern foothill neighborhoods (Etiwanda Heights, Alta Loma) sit in the WUI / CalFire LRA FHSZ and require Chapter 7A construction.
Cost scenarios
| Scenario | Sq ft | Permit | Build | Total |
|---|---|---|---|---|
| minimum | 150 | $1,900 | $67,500 | $69,400 |
| 600 | 600 | $3,100 | $270,000 | $273,100 |
| midpoint | 675 | $3,300 | $303,750 | $307,050 |
| 1000 | 1,000 | $11,500 | $450,000 | $461,500 |
| maximum | 1,200 | $13,200 | $540,000 | $553,200 |
Fee breakdown (as of 2026-04)
Permitting process
Viability (permitted uses)
- Long-term rental: yes Long-term ADU rental permitted; AB 976 (effective 2024-01-01) bars Rancho Cucamonga from imposing owner-occupancy as a permit condition.
- Short-term rental: with-restrictions Rancho Cucamonga regulates STRs separately from ADU permitting; check current STR ordinance and any HOA covenants. Victoria Gardens-area HOAs commonly restrict STR use.
- Office rental: with-restrictions Renting an ADU as outside-tenant office space requires use change beyond residential; consult Planning at 909-477-2750.
- Home office: yes Owner home-office use within an ADU is a permitted accessory residential use.
- Studio / workshop: yes Owner artist studio / workshop use within an ADU is a permitted accessory residential use.
- Agriculture: with-restrictions Limited urban agriculture allowed in residential zones; large-animal keeping limited to specific equestrian overlay districts in Alta Loma.
- Relative support: yes Family / multigenerational use of ADU explicitly permitted. Quote from RCMC 17.100: ADUs serve 'unique needs of elderly and disabled households'.
Incentives
Contacts
Utilities
- Water: Cucamonga Valley Water District (CVWD) · 28d connect · $5,500
CVWD residential meters typically 3/4-inch or 1-inch; monthly meter charges scale with size. Five-year rate series enacted 2022-01-01 (water) with annual adjustments; sewer rate series enacted 2023-07-01. Under-750-sqft ADUs exempt from connection fees per SB 13. - Sewer: Cucamonga Valley Water District (CVWD) collection + Inland Empire Utilities Agency (IEUA) treatment · 28d connect · $4,500
CVWD provides local sewer transmission; IEUA charges a per-EDU sewer-treatment pass-through that CVWD collects. Both bundled into the over-750-sqft permit cost; waived under 750 sqft per SB 13. - Electric: Southern California Edison (SCE) · 30d connect · $1,800
SCE serves all of Rancho Cucamonga. Title 24 2025 solar mandate applies to new detached ADUs; ePlanRC issues solar permits in tandem. - Gas: Southern California Gas Company (SoCalGas) · 21d connect · $1,500
SoCalGas serves Rancho Cucamonga. No city gas-ban ordinance; all-electric ADUs may skip the gas connection.
Property values & taxes
Construction timeline
Realistic total: best 8mo · typical 12mo · worst 18mo
Modular pathway inspectors are experienced with modular
Financing
Insurance impact
Rancho Cucamonga's foothill exposure (Etiwanda Heights, Alta Loma) materially raises homeowner premium and threatens FAIR Plan placement after carrier non-renewals. January 2025 windstorm / Etiwanda Fire history are both rated.
HOA prevalence & preemption
Rancho Cucamonga has unusually high HOA prevalence for a Southern California city - master-planned Victoria, Terra Vista, and Etiwanda Heights communities dominate the city's housing stock. AB 670 (2019) + AB 3182 (2020) preempt outright HOA ADU bans, but design-standards delays under the Carlsbad pattern are common in RC HOAs.
Regulatory overlays (3)
- wui-fire-zone
Northern foothill neighborhoods (Etiwanda Heights, Alta Loma, areas north of Banyan) sit in CalFire LRA FHSZ — published April 2025 by RC Fire District. Triggers Chapter 7A construction (ignition-resistant materials, ember-resistant venting, defensible space). 2014 Etiwanda Fire (2,143 acres) is the local benchmark event. - seismic-retrofit-zone
Cucamonga Fault traverses northern Rancho Cucamonga; SDC D applies citywide and SDC E reaches the foothill thrust zone. ASCE 7-22 detailing required; some parcels need Alquist-Priolo special-studies-zone investigation. - flood-zone
Cucamonga Creek and Day Creek flood-control channels cross the city; FEMA Zone A / AE applies on parcels along those reaches and triggers floodplain elevation + insurance requirements.
Technical envelope (climate & building code)
Climate & energy code
Building code
Amendments:
- Amendment
- Amendment
- Amendment
Contractor market (aggregate)
Legal history (timeline)
Current ordinance: Rancho Cucamonga Municipal Code Chapter 17.100 — Accessory Dwelling Units and Junior Accessory Dwelling Units, adopted 2017-12-13, last amended 2024-11-01
- 2014-04-30 — Etiwanda Fire (2,143 acres) shapes northern Rancho Cucamonga WUI rules (city-policy)
Santa Ana-driven wildfire in San Bernardino National Forest foothills above north Rancho Cucamonga burned 2,143 acres, reinforcing local Chapter 7A enforcement and ember-cast ignition concerns for accessory structures in foothill neighborhoods.
Effect: Solidified the city's WUI defensible-space and Chapter 7A enforcement posture for ADUs in Etiwanda Heights, Alta Loma, and other northern foothill areas. - 2017-12-13 — Rancho Cucamonga adopts dedicated ADU/JADU chapter (RCMC Ch. 17.100) (city-ordinance)
Pulled ADU regulation out of Chapter 17.42 (accessory structures) and into a dedicated Chapter 17.100, aligning with then-new state preemption (SB 1069 / AB 2299).
Effect: Created the current code-organization split: ADUs governed by 17.100 only; explicitly exempt from 17.42 setback / lot-coverage rules. - 2020-01-01 — RCMC 17.100 conformance update for AB 68 / SB 13 / AB 670 cycle (city-ordinance)
Aligned 17.100 with the 2020 statewide preemption package: 60-day clock, fee caps under 750 sqft, four-foot side/rear setbacks for new detached ADUs.
Effect: Codified the four-foot side/rear setback in single-family detached scenarios; mandated direct building-permit intake (no separate Planning application). - 2024-11-01 — Rancho Cucamonga publishes Residential Accessory Structures handout (Rev. 11.2024) (city-policy)
Posted updated handout describing residential accessory-structure permitting that complements the dedicated ADU chapter.
Effect: Current applicant-facing reference for non-ADU accessory structures (sheds, garages); ADUs use separate intake checklists tied to RCMC 17.100. - 2025-01-01 — January 2025 Windstorm response and ePlanRC reliability improvements (city-policy)
City posted recovery / response page following the January 2025 windstorm event; ePlanRC portal usage was prioritized to keep permit intake operational.
Effect: Highlighted Santa Ana wind exposure relevant to ADU design (uplift, ember-cast); reinforced city push toward online-only intake. - 2025-04-08 — Local Responsibility Area Fire Hazard Severity Zone (LRA FHSZ) map released for public review (city-policy)
Rancho Cucamonga Fire District published the State Fire Marshal-recommended LRA FHSZ map covering northern foothill neighborhoods; the District declined to add additional zones beyond the Marshal's recommendation.
Effect: Defined the current city-line FHSZ boundary used to trigger Chapter 7A / WUI requirements on new ADUs in Etiwanda Heights and Alta Loma.
Known issues (2)
- other — Northern foothill neighborhoods (Etiwanda Heights, Alta Loma) sit in the LRA FHSZ - Chapter 7A construction is mandatory for new ADUs and adds 8-15% to materials cost. Insurance carriers increasingly non-renew foothill homeowner policies, pushing owners to FAIR Plan + difference-in-conditions stacks.
- other — High HOA prevalence (~55%) means design-standards review can stretch ADU approval beyond the 60-day state ministerial clock even though outright HOA bans are state-preempted.
San Bernardino County — county ADU rules and overlays
County ADU ordinance
California state — ADU law and programs
State ADU law
California has the most aggressive statewide ADU preemption regime in the US, built from ~15 bills passed 2019-2025 and enforced by the Department of Housing and Community Development (HCD). The 2026 HCD ADU Handbook addendum (in effect with the 2025 Title 24 code cycle) is the operative state-level reference. The regime does four things at once: (1) preempts local zoning that would ban or unreasonably restrict ADUs; (2) imposes by-right ministerial approval with short statutory deadlines; (3) caps fees and utility-connection charges; and (4) empowers HCD to void non-compliant local ordinances.
State HOA preemption
California has the strongest statewide HOA-preemption regime in the US for accessory dwelling units, built from two bills: AB 670 (2019) voided ADU-prohibiting covenants on single-family residential lots, and AB 3182 (2020) extended and codified the preemption into the Davis-Stirling Common Interest Development Act (Civil Code §§ 4740 / 4741). The combination prohibits common-interest communities from banning ADUs, restricting rentals below 25% of separate interests, or treating ADUs as separate HOA interests. Limits remain: HOAs retain authority over reasonable design standards and statutory height limits, and the 2026 Carlsbad case (CalMatters coverage) established that an HOA's documented design-standards regime can effectively delay or constrain ADU approval short of outright prohibition.
State financing programs
California's flagship state-level ADU financing program — the CalHFA ADU Grant Program — is paused and has not been refunded since the original $100 million allocation was fully deployed 2023-12-28. The program provided up to $40,000 per qualifying homeowner for pre-construction and non-recurring closing costs and financed approximately 2,500 ADUs in two rounds. As of 2026-04, no new funding round has been announced in the state budget. CalHFA continues to publish anti-scam warnings because bad actors actively solicit homeowners claiming access to grant funds that no longer exist. State-level financing activity has shifted to local pilot programs (San Francisco, San Jose, Los Angeles, San Diego) and private financing products (Fannie Mae ADU mortgage, HELOC, construction-to-permanent).
State housing programs
California's state-level ADU programs are concentrated at HCD (technical guidance, ordinance review, enforcement) and the paused CalHFA grant pipeline (covered under stateFinancing). The state does not operate a central pre-approved ADU plan library — instead, AB 1332 (2024) created a preemption framework for local pre-approved plans with a 30-day ministerial-approval deadline, and major cities (Los Angeles, San Diego, San Jose, Sacramento, Berkeley) have rolled out their own plan catalogs. The California YIMBY coalition and other housing-policy organizations play an influential role in bill drafting; they are not state agencies but effectively drive much of the ADU legislative agenda. The Title 24 code cycle (now 2025, in effect for 2026 permits) is the authoritative building-code baseline.
Federal (United States) — ADU-relevant rules and programs
Federal ADU law
The United States has no federal statute that directly regulates accessory dwelling unit entitlement or design. Land-use authority over ADUs resides with states and local governments under the traditional police power. Federal engagement is limited to financing (Fannie/Freddie/FHA/VA/USDA), flood insurance (FEMA/NFIP), and discretionary housing programs (HUD), which are recorded in sibling sections of this file.
Federal financing programs
Federal housing-finance agencies and GSEs set nationwide underwriting rules that govern whether an ADU can be financed, appraised, and counted toward mortgage qualifying income. The relevant actors are Fannie Mae, Freddie Mac, FHA (HUD), VA, and USDA Rural Development.
Federal tax credits
There is no ADU-specific federal tax credit. ADUs may incidentally qualify for existing federal energy-efficiency and clean-energy tax credits when the ADU construction includes qualifying measures.
Federal housing programs
HUD administers several discretionary programs that can fund ADU-related activity at the grantee's election, but none is an ADU-specific program.
ZIP Codes
- 91701
- 91730
- 91737
- 91739
Post Office
- 10950 Arrow Rte, 91729
- 6649 Amethyst Ave, 91701
Locale Names
- Alta Loma