ADU Pass
Alpine
San Diego County portion
Also in: No County
ADU Pass helps homeowners in Alpine, San Diego County, California navigate the permit paperwork for building an accessory dwelling unit. This area covers 1 ZIP code.
Map
ADU details
ADU legality: allowed
California state preemption + County of San Diego ordinance govern Alpine ADUs. Alpine CPG advisory only. Most of Alpine sits in Cleveland National Forest interface VHFHSZ — Chapter 7A and 100-foot defensible-space requirements apply almost universally.
Cost scenarios
| Scenario | Sq ft | Permit | Build | Total |
|---|---|---|---|---|
| minimum | 150 | $1,850 | $78,000 | $79,850 |
| 600 | 600 | $1,965 | $312,000 | $313,965 |
| midpoint | 675 | $1,788 | $351,000 | $352,788 |
| 1000 | 1,000 | $9,892 | $520,000 | $529,892 |
| maximum | 1,200 | $11,963 | $624,000 | $635,963 |
Fee breakdown (as of 2026-04)
Permitting process
- Pre-application + parcel zoning lookup (~7d)
Verify parcel zone (typically SR-1/SR-2/SR-4/SR-10 in Alpine) via County Z-maps; check VHFHSZ status, ALUC overlay (none in Alpine), and Coastal LCP (does not reach Alpine). - Plan submittal via Accela Citizen Access (~5d)
Submit ADU Building Permit application through publicservices.sandiegocounty.gov (Accela). PDS now accepts most ADU submittals digitally; some Alpine applicants still use the in-person Overland Avenue counter. - PDS combined plan check (zoning + building + grading) (~50d)
First-cycle review by PDS Planning, Building, and (if site has slope) Grading. Alpine FPD parallel review for defensible space, fire flow, driveway access. CAL FIRE review for parcels in State Responsibility Area (SRA). - Corrections cycle 1 (~28d)
Applicant resubmits to address PDS plan-check comments. Typical Alpine corrections: WUI Chapter 7A material specs, defensible-space exhibit, septic perc test (if not Padre Dam sewered). - Plan check cycle 2 (~21d)
Second review confirms compliance. ~2 cycles is the typical Alpine count for a clean WUI submittal. - Permit issuance + fee payment (~5d)
Pay permit fees + impact fees (proportional, only if >750 sqft) + Alpine FPD review fee. Permit downloadable from Accela. - Construction inspections
Foundation, framing, MEP rough-in, insulation, fire (defensible space verification), final. Alpine FPD inspects defensible space pre-final.
Viability (permitted uses)
- Long-term rental: yes (California Gov. Code 65852.2(a)(7) and 2024 owner-occupancy preemption (AB 976))
- Subject to AB 1482 statewide rent cap (5% + CPI, max 10% per year) where applicable
- Short-term rental: with-restrictions (San Diego County Code Title 2 Division 1 Chapter 6 (Short-Term Residential Occupancy ordinance))
- Short-term-rental registration required for unincorporated parcels
- Transient Occupancy Tax (TOT) collection responsibility falls on operator
- Alpine FPD defensible-space verification expected
- Office rental: no (County Title 6 - ADU defined as residential occupancy) ADU is residential by definition; commercial/office tenant rental violates the use restriction.
- Home office: with-restrictions (County Code home-occupation provisions)
- Home-occupation permit required for client visits
- No outside employees on residential parcels
- Signage strictly limited
- Studio / workshop: yes Personal artist/maker studio is acceptable accessory residential use; ADU must remain a complete dwelling unit.
- Agriculture: with-restrictions Many Alpine parcels carry SR-2/SR-4/SR-10 zoning that permits limited animal-keeping (chickens, horses); commercial agriculture requires zoning verification. ADU itself cannot be used for agricultural processing.
- Relative support: yes (California Gov. Code 65852.22 (JADU) + Rev. & Tax. Code 74.3 New Construction Exclusion) Multigenerational ADU explicitly permitted; intergenerational ADU may qualify for Rev. & Tax. Code 74.3 New Construction Exclusion if filed timely.
Incentives
- CalHFA ADU Grant Program — Up to $40,000 one-time predevelopment (paused / waitlisted statewide as of 2026) (Moderate-income owner-occupants)
- Prop 13 - primary dwelling base-year value not re-triggered by ADU
- PDS Pre-Approved Dwelling Unit Plans (~85% complete as of 2026) — County maintains pre-approved dwelling unit plans usable as detached ADUs in Alpine; bypasses architectural plan check.
- Impact Fee Waivers SB 13 — Impact fees waived for ADUs under 750 sqft. The dominant Alpine ADU sizing strategy.
- AB 1033 condominium conversion pathway (effective 2026-04-04 in unincorporated SD County) — Alpine ADU owners can convert ADU to separately-saleable condominium under the 2026-03-04 County ordinance amendment.
Pre-approved plans San Diego County Pre-Approved Dwelling Unit Plans · 8 free designs · 25% plan-review fee waiver · saves ~4 weeks
Contacts
Staff: PDS Zoning Counter (ADU Application Intake) PDSZoningPermitCounter@sdcounty.ca.gov, Alpine Fire Protection District (FPD review) (Plan-check + defensible-space inspection) admin@alpinefire.org
Utilities
- Water: Padre Dam Municipal Water District (Alpine portion of service area) · 30d connect · $5,500
Padre Dam serves Alpine for water and sewer (where sewered). Outside Padre Dam service boundaries (e.g., upper rural Alpine), parcels rely on private wells regulated by County Department of Environmental Health and Quality (DEHQ). - Sewer: Padre Dam Municipal Water District (where sewered) or on-site septic via County DEHQ · 30d connect · $8,500
Most Alpine parcels outside the village core rely on on-site septic. ADU on septic must add capacity verification or new system; perc test typically $1,200-$2,000 plus engineering. - Electric: San Diego Gas & Electric (SDG&E) · 60d connect · $4,500
SDG&E serves all of Alpine. Separate meter optional for ADU; most owners share the primary residence meter to avoid extra service fees. - Gas: SDG&E (where natural gas is available) or propane tank · 30d connect · $2,500
Natural gas serves the Alpine village core; rural east-Alpine parcels typically use propane (Suburban Propane, Ferrellgas, or AmeriGas as common providers).
Property values & taxes
Market rent by ADU size
| Sq ft | Rent |
|---|---|
| 400 | $1,650/mo |
| 600 | $2,050/mo |
| 800 | $2,400/mo |
| 1,000 | $2,700/mo |
| 1,200 | $2,950/mo |
Construction timeline
Realistic total: best 9mo · typical 13mo · worst 22mo
Alpine GC bench is thin - most Alpine ADU projects use San Diego or East County GCs commuting via I-8, adding lead-time. WUI build (Chapter 7A) adds 2-4 weeks for ignition-resistant materials. Septic install (when needed) adds 4-8 weeks.
Modular pathway inspectors are occasional with modular
Financing
State ADU loans:
- CalHFA ADU Grant Program (CalHFA) up to $40,000
- HCD ADU Funding index (California HCD)
Insurance impact
Alpine premiums substantially higher than coastal SD County due to Cleveland NF WUI exposure. Many carriers non-renewed in Alpine 2023-2025; CA FAIR Plan often the only available carrier for parcels in highest-risk zones (adds ~$700-$1,200/yr premium delta on the ADU vs. comparable non-WUI parcels).
HOA prevalence & preemption
Alpine has limited HOA coverage - concentrated in the Rancho Palo Verde, Alpine Heights, and a few newer subdivisions. Most parcels are unrestricted CDP land. State preemption (AB 670/AB 3182) voids HOA ADU bans where they exist.
Regulatory overlays (2)
- wui-fire-zone — Most of Alpine sits in Cleveland National Forest / Sycamore Canyon WUI; designated Very High Fire Hazard Severity Zone (VHFHSZ) in either State Responsibility Area or Local Responsibility Area depending on parcel. · +21d · +12% cost
Triggers California Building Code Chapter 7A: ignition-resistant siding/eaves/decks, dual-pane tempered windows, 1/8-inch vent screens, Class A roofing. Pub. Res. Code 4291: 100-foot defensible space. Alpine FPD reviews driveway access (minimum 12-ft clear width, turnaround for trucks) and fire flow. Adds ~12% to build cost and ~3 weeks to plan check. (map) - flood-zone — FEMA Flood Insurance Rate Maps show Special Flood Hazard Areas along Sweetwater River and Viejas Creek tributaries crossing southern Alpine; small fraction of parcels affected. · +14d · +4% cost
Elevation certificate required for SFHA parcels; ADU finished floor must be 1 foot above base flood elevation. Most Alpine parcels are uphill of these corridors and unaffected. (map)
Technical envelope (climate & building code)
Climate & energy code
Building code
Amendments:
- Amendment
- Amendment
- Amendment
- Amendment
Contractor market (aggregate)
Legal history (timeline)
Current ordinance: San Diego County Zoning Ordinance Title 6 - ADU/JADU provisions (as amended 2026-03-04), adopted 2020-12-09, last amended 2026-03-04
- 1979-04-13 — Alpine Community Plan adopted as part of County General Plan (city-ordinance)
Original Alpine Community Plan adopted by the San Diego County Board of Supervisors as a sub-element of the County General Plan, defining Alpine's land-use designations.
Effect: Established Alpine's village core (along Alpine Boulevard between Tavern Road and West Victoria Drive) and rural-residential surround as the long-range zoning framework; parcels designated Semi-Rural Residential (SR-1, SR-2, SR-4, SR-10) outside the village dominate the housing stock and govern ADU density today. - 2011-08-03 — Alpine Community Plan update incorporated into County General Plan Update (city-ordinance)
Alpine Community Plan re-adopted and incorporated into the August 2011 County General Plan Update.
Effect: Re-confirmed Semi-Rural and Rural-Lands designations across most of Alpine, preserved the village commercial corridor, and tied Alpine future-housing capacity to county-administered residential zones - which is the framework the modern ADU ministerial track operates within. - 2020-12-09 — San Diego County Ordinance No. 10693 (ADU conformance to AB 68 / SB 13) (city-ordinance)
Board of Supervisors adopted Title 6 zoning amendments conforming the unincorporated ADU ordinance to the 2019 state ADU reform package.
Effect: Alpine parcels covered: ministerial 60-day approval, impact-fee exemption for ADUs <750 sqft, removal of owner-occupancy mandate (then through 2024, made permanent by AB 976). - 2023-06-28 — San Diego County Ordinance No. 10749 (ADU update for AB 2221/SB 897) (city-ordinance)
County conformed Title 6 to AB 2221/SB 897 height and design-review limits; did not opt into AB 1033 at this stage.
Effect: Alpine ADUs benefited from clearer 16-ft single-story / up-to-25-ft two-story envelope and tightened plan-check timelines. - 2026-03-04 — San Diego County ADU Zoning Ordinance Amendment - AB 1033 condominium conversion adoption (city-ordinance)
Board of Supervisors voted unanimously to adopt the ADU Ordinance Amendment incorporating new mandatory state laws and an AB 1033 condominium-conversion program for unincorporated communities.
Effect: Alpine parcel owners now have the option (effective 2026-04-04) to convert an ADU into a separately-saleable condominium unit. Additional implementation parameters are due by 2026-07-02. Substantially changes ADU exit-strategy economics in Alpine because it permits sale of the ADU independent of the primary residence.
Known issues (2)
- policy-review (since 2026-03) — Board of Supervisors directed PDS to return within 120 days (2026-07-02) with additional parameters governing the AB 1033 condominium-conversion track. Until those parameters are adopted, Alpine ADU owners considering condo separation should expect implementation uncertainty. (source)
- other (since 2023-01) — Multiple carriers exited Alpine market 2023-2025 citing wildfire risk; many ADU-eligible parcels can only obtain coverage through CA FAIR Plan + difference-in-conditions wrap. This is the dominant Alpine ADU economic friction outside permitting. (source)
San Diego County — county ADU rules and overlays
County ADU ordinance
San Diego County regulates ADUs on parcels in the unincorporated county under Title 6 of the County Code (Zoning Ordinance), Sections 6156.x. The county's ADU framework layers on top of California Government Code sections 65852.2 (ADU) and 65852.22 (JADU), which preempt many local standards statewide; the county ordinance fills in the locally-controlled parameters (setbacks, design standards, parking in non-transit unincorporated areas, fire-safe design in VHFHSZ) that state law leaves to local choice. The current ordinance reflects amendments adopted 2020 (Ord. No. 10693) and 2023 (Ord. No. 10749) to conform with AB 68 / AB 881 (2019), AB 976 (2019 owner-occupancy elimination through 2024), SB 13 (2019 fee reductions), AB 2221 / SB 897 (2022 design/permit clarifications), and AB 1033 (2023 condo-ADU optional program; San Diego County has not opted into AB 1033 condo separation as of 2026-04-20). The county permits up to one ADU plus one JADU per single-family parcel by right, and the state-mandated two ADUs per multifamily lot; parking is not required on ADUs within 1/2 mile of transit. The county's distinct contributions on top of state law are the fire-hardening / defensible-space design standards for ADUs sited in Very High Fire Hazard Severity Zones, the airport-noise compatibility review for ADUs within Airport Land Use Compatibility Plan (ALUCP) zones, and the Coastal Development Permit (CDP) requirement for ADUs in the county's certified Local Coastal Program (LCP) jurisdiction.
- San Diego County Code of Regulatory Ordinances Title 6 (Zoning) — Accessory Dwelling Unit provisions
- PDS ADU Technical Bulletin and applicant handouts
- Ordinance No. 10693 — 2020 ADU ordinance conforming to AB 68 / AB 881 / SB 13
- Ordinance No. 10749 (approximate) — 2023 ADU ordinance update for AB 2221 / SB 897 / AB 1033
State-floor overlay: California state law (Gov. Code 65852.2, 65852.22) preempts most local ADU regulation. The state sets ministerial-approval requirements, caps fees, mandates 60-day permit review, forbids local owner-occupancy requirements through 2024 (extended effectively through AB 976 / subsequent amendments), sets minimum allowed sizes (850 sqft one-bedroom, 1000 sqft two-bedroom), forbids parking requirements within 1/2 mile of transit or on replacement-covered-parking ADUs, and caps impact fees at zero for ADUs under 750 sqft. San Diego County's ordinance reiterates and applies these floors, adding only the locally-controlled fire, airport, and coastal overlays. Where a project is in a VHFHSZ or coastal-commission jurisdiction, state ADU preemption still applies to the ADU allowance itself but does not preempt the county's separate fire and coastal authority over site-design standards.
County regulatory overlays
San Diego County administers or co-administers several overlay regimes that materially affect ADU siting on unincorporated parcels: (1) the California Coastal Commission's jurisdiction along the coastal zone (a narrow band up to 5 miles inland in some places), implemented through the county's certified Local Coastal Program (LCP) covering unincorporated coastal segments; (2) Very High Fire Hazard Severity Zones (VHFHSZ) designated by CAL FIRE and reviewed by the State Board of Forestry, which cover very large portions of the unincorporated back-country and drive defensible-space, ignition-resistant-construction, and access requirements; (3) FEMA Special Flood Hazard Areas (SFHA) along the San Diego River, San Dieguito River, San Luis Rey River, Otay River, Sweetwater River, Tijuana River, and associated coastal zones; and (4) Airport Land Use Compatibility Plans (ALUCP) administered by the San Diego County Regional Airport Authority's Airport Land Use Commission around MCAS Miramar (federal military), NAS North Island / Naval Outlying Landing Field Imperial Beach (federal military), Gillespie Field (Santee, county-owned), McClellan-Palomar (Carlsbad, county-owned), Brown Field (Otay Mesa, City of San Diego), Montgomery-Gibbs Executive (Kearny Mesa, City of San Diego), Ramona Airport (county-owned), Fallbrook Community Airpark (county-owned), Oceanside Municipal, and Jacumba Airport. Seismic-retrofit overlays are not a county-administered regime in San Diego (unlike parts of Los Angeles / San Francisco); California seismic building-code compliance applies statewide through the California Building Code adopted by the county.
- California Coastal Commission / County Local Coastal Program (LCP) — The county's LCP covers the unincorporated coastal segments near Del Mar Mesa, Torrey Pines extensions, Crest / Harmony Grove (tributary areas), and the Camp Pendleton / Oceanside boundary. An ADU within the coastal zone requires a Coastal Development Permit (CDP) unless categorically excluded; most single detached ADUs qualify for an Administrative CDP (noticed but ministerial-like) while those in sensitive-biological or visually-sensitive settings may require a heard CDP. The Coastal Commission retains appeal jurisdiction over county CDPs within the defined appeals area. State law (Gov. Code 65852.2(j)) preserves the CDP requirement for ADUs in the coastal zone notwithstanding the otherwise-ministerial state ADU framework.
- CAL FIRE / State Board of Forestry Very High Fire Hazard Severity Zones (VHFHSZ) and County Fire Code — Very large portions of unincorporated San Diego County — most of the East County back-country including Julian, Warner Springs, Descanso, Pine Valley, Jacumba, Campo, Boulevard, Dulzura, Potrero, Palomar Mountain, Cuyamaca, and the San Diego / Cleveland National Forest interface — are designated VHFHSZ in either the State Responsibility Area (SRA) or the county's Local Responsibility Area (LRA). An ADU in a VHFHSZ must comply with California Building Code Chapter 7A (WUI-rated exterior materials: ignition-resistant siding, dual-pane windows, 1/8-inch-max vent screens, Class A roofing, non-combustible eaves / soffits / decks), minimum 100-foot defensible-space per Pub. Res. Code 4291, minimum driveway width and turnaround per fire-district standards, and minimum fire-flow water supply (2,500 gpm residential standard, reduced for sprinklered ADUs per Sec. R313). CAL FIRE or the local FPD (Alpine, Bonita-Sunnyside, Deer Springs, Julian-Cuyamaca, Lakeside, North County, Pine Valley, Rancho Santa Fe, Rural FPD of San Diego County, Valley Center, etc.) reviews the ADU permit. The 2025 wildfire season reinforced these requirements; no county-wide moratorium has been imposed, but permit backlogs lengthen post-fire when affected areas surge rebuild applications.
- FEMA Special Flood Hazard Areas (SFHA) — National Flood Insurance Program — The county administers FEMA NFIP floodplain regulations for unincorporated parcels. Principal SFHA extents are along the San Luis Rey River (Bonsall, Pala, Pauma), San Dieguito River (Lakeside, Ramona uplands), San Diego River (Lakeside, Santee extensions), Sweetwater River (Spring Valley extensions), Otay River (Jamul, Dulzura, Otay Mesa extensions), and Tijuana River estuary (Tijuana / Imperial Beach extensions). ADUs in an SFHA require lowest-floor elevation to or above Base Flood Elevation plus 1 ft county freeboard, flood vents on enclosures below BFE, anchoring, and a post-construction Elevation Certificate. 2024-2025 saw several FEMA FIRM revision studies for Otay, San Luis Rey, and Sweetwater watersheds; owners should confirm current effective panel before design.
- Airport Land Use Compatibility Plans (ALUCP) — San Diego Regional Airport Authority ALUC — The San Diego County Regional Airport Authority serves as the ALUC for all airports in the county. ALUCP airport influence areas (AIAs) extend roughly 2-5 miles beyond each airport depending on runway configuration and establish safety zones (Zones 1-6) and noise contours (60/65/70 dB CNEL). Principal ALUCP overlays affecting unincorporated parcels are MCAS Miramar (extensive AIA covering Scripps Ranch fringes, Miramar Ranch North, Tierrasanta approaches, into unincorporated Rancho Santa Fe / Poway fringes), Gillespie Field (AIA extending into unincorporated Lakeside, El Cajon fringes, Bostonia), McClellan-Palomar (Carlsbad-adjacent unincorporated areas), Ramona Airport (large rural AIA), and Fallbrook Community Airpark (Bonsall / Fallbrook). An ADU in a safety zone may face density restrictions, CC&R / avigation-easement recording requirements, and noise-attenuation construction standards (STC-rated windows, forced-air HVAC with acoustic treatment). The ALUC reviews county-referred projects; in a safety-zone conflict the county may override only by a super-majority Board vote per PUC 21676.
- San Diego County Biological Mitigation Ordinance / Multiple Species Conservation Program (MSCP) — The county's MSCP covers south county unincorporated areas and establishes Pre-Approved Mitigation Areas and a Biological Mitigation Ordinance that triggers biological review for grading and construction in designated preserve-land overlays. An ADU outside the existing dwelling footprint that requires grading in a designated MSCP preserve or Biological Resource Core / Linkage area will trigger a biological review / mitigation obligation on top of the ministerial ADU permit. Inside a parcel's previously-disturbed building envelope the MSCP typically does not add requirements. The East County MSCP Subarea Plan remains pending final approval as of 2026-04-20.
County permitting (unincorporated parcels)
The County of San Diego Planning & Development Services (PDS) department is the single-point-of-contact for ADU permits on parcels in the unincorporated county. Unincorporated San Diego County covers approximately 3,570 square miles (about 79% of the county's 4,526 sqmi land area) and includes densely developed fringe areas (Ramona, Alpine, Lakeside, Spring Valley, Fallbrook, Valley Center), rural back-country (Julian, Warner Springs, Jacumba, Boulevard, Campo), and tribal lands (which are not county-permitted). The 18 incorporated cities (San Diego, Chula Vista, Oceanside, Escondido, Carlsbad, Vista, San Marcos, El Cajon, Santee, La Mesa, Encinitas, National City, Poway, Coronado, Imperial Beach, Lemon Grove, Del Mar, Solana Beach) permit their own ADUs independently. PDS combines planning / zoning review, building plan review, grading / drainage review, fire-district referral (most unincorporated areas are served by CAL FIRE / County Fire Authority or a local Fire Protection District rather than a city fire department), and environmental review (CEQA applicability is normally exempt for ministerial ADUs per Gov. Code 65852.2(f) and Pub. Res. Code 21080(b)(8)).
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 Code
- 91901
Post Office
- 2127 Arnold Way, 91901