San Diego ADU Guide: What You Can Build, What It Costs, and Whether It Pencils

San Diego has some of the most permissive accessory dwelling unit rules in California, and also some of the most misunderstood. The single most valuable thing on this page is probably the rule most owners have never heard: on an existing multifamily property, the City allows up to eight detached ADUs. A fourplex can legally become eight units. That is not a loophole, it is the Municipal Code.

Last reviewed October 2026 by Twana Rasoul, DRE# 02026495. City rules current to Information Bulletin 400, January 2026 edition. State law current through the 2026 legislative changes listed below.

What's in this guide

What this page is and is not. I am a real estate agent. I am not an architect, a contractor, or a land use attorney. This page summarizes the City of San Diego's published ADU regulations and current market cost data so you can evaluate a property with realistic expectations. Rules change, and what applies to your specific parcel depends on its zone, overlays, and history. Verify with the City's Development Services Department and a licensed design professional before you buy or build.

What changed in 2026

ADU law moved a lot this year, and most of the movement was in the owner's favor. If you looked at an ADU project a year ago and the timeline or the fees killed it, the math may be different now.

ChangeEffectiveWhat it means for you
SB 543 Jan 1, 2026 The City must determine whether your application is complete within 15 days. Miss the deadline and it is automatically deemed complete. Missing items must be listed in writing, and on resubmittal the City can only review what it already flagged. ADUs and JADUs under 500 sq ft are also now exempt from school impact fees.
AB 1154 Jan 1, 2026 JADU owner-occupancy requirements now apply only when the JADU shares sanitation facilities with the primary dwelling. If it has its own, you are not required to live there.
AB 462 Oct 15, 2025 Big one for coastal San Diego. Agencies with a certified Local Coastal Program must act on an ADU Coastal Development Permit within 60 days of a complete application. Miss it and the ADU is deemed approved.
AB 253 Oct 10, 2025 On projects of ten units or fewer, if plan review drags past 30 business days you can hire a certified private plan checker. If the agency then does not respond within 10 days, the permit is deemed approved.
AB 1308 2025 Final inspections must happen within 10 business days of a completion notice on small projects. Failing to do so is also a Housing Accountability Act violation.
AB 2533 Jan 1, 2025 Expanded amnesty for unpermitted ADUs built before January 1, 2020. Covered in detail below, and it is the most commercially useful item on this list.
AB 1033, San Diego County April 2026 The County Board of Supervisors adopted an opt-in ordinance on March 4, 2026 allowing qualifying ADUs in unincorporated areas to be sold separately as condominiums. See selling an ADU separately.

Why this matters to a buyer rather than just a builder. Most of these changes put hard deadlines on the City and take discretion out of the process. That makes an ADU project more predictable to underwrite, which is the thing that actually decides whether a lot with ADU potential is worth paying for. A year ago, "the permit could take as long as it takes" was a real reason to discount that potential to zero. It is a weaker reason now.

How many ADUs you can actually build

This depends entirely on what your property already is. The City treats single-dwelling lots and multiple-dwelling lots very differently, and most online guides only cover the first.

What you ownWhat you can add
Single-family home in a single-dwelling zone One attached or detached ADU, plus one converted ADU, plus one JADU. Guest quarters and non-habitable accessory structures are also permitted.
Existing multi-unit building in a multiple-dwelling zone Up to eight detached ADUs, but never more than the number of units that already exist. Plus conversions of non-habitable space up to 25% of existing units, minimum one. Attached ADUs are not allowed. JADUs are not allowed unless a previously conforming single dwelling exists.
New multi-unit building being proposed Up to two detached ADUs. No attached ADUs.
Single-family home sitting in a multiple-dwelling zone Single-dwelling zone rules apply.

The multifamily opportunity most owners miss

Read that second row again. If you own an existing fourplex in a multiple-dwelling zone, the detached ADU allowance is capped at eight and at your existing unit count. Four existing units means up to four detached ADUs. A duplex means up to two. An eight-unit building means up to eight.

On top of that, you can convert non-habitable space, storage rooms, unused laundry areas, enclosed parking, into additional ADUs at 25% of your existing unit count, minimum one.

What this means in practice. A fourplex that currently produces four rents can, with enough lot area and the right site plan, become an eight-door property. The economics of that are completely different from buying a fourplex and holding it. This is the single biggest value-add play available on San Diego 2-4 unit property right now, and it is the thing I spend the most time on with investor clients.

The constraints are practical rather than regulatory: lot area, parking and access, setbacks, utility capacity, and whether a lender will finance it. Not every fourplex can absorb four detached units. But the ones that can are frequently priced as though they cannot.

The ADU Bonus Program, and what changed in 2025

San Diego's ADU Home Density Bonus Program lets you build additional market-rate ADUs in exchange for deed-restricting affordable ones. For several years it had no hard cap, and some single-family lots produced a dozen or more units. That drew significant political pressure.

On June 16, 2025, the City Council adopted changes by a 5-4 vote. The program still exists, but it now has limits.

Lot area (excluding environmentally sensitive land)Max total ADUs and JADUs
Up to 8,000 sq ft4
8,001 to 10,000 sq ft5
Over 10,000 sq ft6

Other current requirements under the bonus program:

  • Geography. Inside a Sustainable Development Area, one bonus ADU per qualifying deed-restricted ADU. Outside those areas, the maximum is one bonus ADU plus one deed-restricted ADU.
  • Zone exclusions. Not allowed in RS-1-1 through RS-1-4 or RS-1-8 through RS-1-11, unless the site is in a High or Highest Resource CTCAC Opportunity Area and designated residential in the land use plan.
  • Fire. In a Very High Fire Hazard Severity Zone the lot must front an improved public street with at least two evacuation routes. Bonus ADUs are prohibited on cul-de-sacs and on lots with a single point of ingress and egress.
  • Parking. One space per affordable or bonus ADU outside a Transit Priority Area.
  • Sprinklers. Required in affordable and bonus ADUs.
  • Trees. Minimum one, plus two per 5,000 sq ft of lot area.
  • Housing Commission agreement. A written agreement with the San Diego Housing Commission is required before the first permit.
  • Community Enhancement Fee. Applies based on gross floor area of affordable and bonus ADUs, with exclusions for affordable units meeting deed-restriction and location criteria.
  • For sale. Bonus program ADUs can now be sold individually rather than only rented.

If you are buying coastal, read this. Several of these ordinances are not yet effective inside the Coastal Overlay Zone. The City states the regulations take effect there only once the California Coastal Commission certifies them. That includes the 2025 ADU and JADU amendments, Housing Action Package 2.0, and the 2024 Land Development Code update. If the property is coastal, the rules that apply to it may be different from the rules on this page, and that difference can decide whether a project is viable. Confirm with Development Services for the specific parcel.

Size, setbacks, height and parking

ItemADUJADU
Size 150 to 1,200 sq ft. Conversions of existing structures are exempt from the 1,200 cap, and up to 150 sq ft may be added for ingress and egress. 150 to 500 sq ft, within an existing or proposed single dwelling or attached garage.
Side and rear setbacks Generally may extend to the property line, subject to fire separation. If the neighbor is residential and the ADU exceeds 16 ft, 4 ft applies. In a Very High Fire Hazard Severity Zone, 4 ft minimum regardless of height. Follows the primary dwelling's setbacks.
Height Two stories on single-dwelling lots for detached ADUs. Must still meet base and overlay zone height limits. N/A, inside the existing dwelling.
Parking None required outside the Coastal Overlay Zone. Inside it, one space may be required in the Beach Impact Area, with exemptions for units 500 sq ft or less and attached units. None required.
Owner occupancy Not required. Required, with limited exceptions. A recorded Junior Unit Agreement is required and a JADU cannot be sold separately.

Converting a garage generally does not require replacing the lost parking. That single rule is why garage conversions remain the cheapest path to a legal second unit on most San Diego lots.

What it actually costs in 2026

These are current San Diego build figures. All-in means design, permits, site work and utilities, not just the structure.

TypeSizeAll-in costPer sq ft
Garage conversion~400 sq ft$80K to $200Kvaries widely
Detached 1BR500 sq ft~$300,000~$600
Detached 2BR750 sq ft~$350,000~$465
Detached 2BR/2BA1,000 sq ft~$425,000~$425
Detached 3BR1,200 sq ft~$450,000~$375
Two ADUs together800 + 1,200~$615,000~$310

Two patterns worth internalizing. Small units cost more per foot, because a kitchen and a bathroom cost roughly the same whether they serve 500 square feet or 1,200. And a second unit built at the same time costs roughly 85% of the first, which is why the two-ADU line above lands at $310 per foot instead of $465.

Line items that catch people: basic site work on a level lot with good access runs around $35,000, utilities and separate metering typically $15,000 to $30,000 or more, and City of San Diego permits and fees have been running roughly $13 to $28 per square foot. Impact fees generally apply to ADUs over 750 sq ft.

Pre-approved plans, and how long this actually takes

The City of San Diego accepts pre-approved ADU plan sets from three sources, 26 plan options in total: the County of San Diego (6 plans, free), the City of Chula Vista (12 options), and Encinitas PRADU (8 plans, free). Sizes run from a 224 sq ft studio up to 1,200 sq ft.

Using one matters for two reasons. Under Government Code 65852.27, a complete application for a detached ADU using a qualifying pre-approved plan must be approved or denied within 30 days. And you skip most of the custom design spend.

Pre-approved planCustom design
Design phaseMinimal8 to 16 weeks
Plan check30-day statutory clock, 60 to 90 days to issuance with corrections60 to 120 days
Construction4 to 6 months4 to 6 months
Total to occupancy6 to 12 months8 to 16 months
Design and plan-check savingsRoughly $5,500 to $18,000Baseline

"Occupancy" means the first rent check. That is the number to underwrite against, not the permit date. From the day you start, you are carrying design, permit and construction costs for roughly six months to a year before the unit produces anything. If you are financing the build, that is also months of interest with no offsetting income. Budget for the gap rather than assuming rent starts when the permit issues.

Three things that break pre-approval. Changing the footprint, bedroom or bath count, structure, or roof form generally sends the project back to standard plan check. The 30-day clock applies only to detached ADUs with a complete application. And the 2025 California Building Standards Code took effect January 1, 2026, so some published plan sets need per-project updates. Confirm in writing that the specific plan is current before you rely on the timeline.

Coastal Overlay projects run on their own 60-day Coastal Development Permit clock and are not covered by the 30-day rule, though AB 462 now forces a decision there too.

Whether the numbers work

San Diego ADU rents in recent reporting have run roughly $1,200 to $2,000 for a studio, $1,500 to $2,500 for a one-bedroom, and $2,000 to $3,500 for a two-bedroom, depending heavily on location and finish.

Here is what that produces against build cost, assuming 30% of gross rent goes to vacancy, maintenance, insurance, and the property tax increase from the added improvement.

Illustrative. Your costs, rents, and tax treatment will differ. These assume all-cash build and no financing cost.
ScenarioBuildRent/moNet/yrReturn on cost
Garage conversion, studio$150,000$1,700$14,2809.5%
Detached 500 sq ft, 1BR$300,000$2,000$16,8005.6%
Detached 750 sq ft, 2BR$350,000$2,400$20,1605.8%
Detached 1,200 sq ft, 3BR$450,000$3,000$25,2005.6%

The garage conversion wins, and it is not close. A 9.5% return on cost against roughly 5.6% to 5.8% for new detached construction. If you have a convertible garage, that is almost always the first move. The detached builds are not bad returns for San Diego, but they are a long-horizon play justified by appreciation and added property value, not by yield alone.

Two things this table does not capture. An ADU adds value to the property beyond its rent stream, though appraisers have historically struggled with ADU comps, so do not assume dollar-for-dollar. And if you are financing the build, interest cost comes directly off these returns.

Financing an ADU, and using the rent to qualify

This is where ADUs get interesting for buyers rather than just existing owners, and the rules improved recently.

Fannie Mae, Freddie Mac and FHA all now allow ADU rental income to help you qualify on a one-unit primary residence. The general shape is the same across all three:

ProgramHow much rent countsKey conditions
Fannie Mae 75% of lease or market rent, capped at 30% of total qualifying income Purchase and limited cash-out refinance only. With under 12 months of landlord experience, counted rent cannot exceed the subject property's PITIA.
Freddie Mac Up to 75% of lease, capped at 30% of stable monthly income Purchase and no-cash-out refinance. Landlord education required unless you have a year of experience. Full appraisal required with ADU comps.
FHA 75% of the lesser of appraised market rent or lease, capped at 30% of effective income. 50% for a proposed ADU under 203(k). One-unit primary residence with one ADU. No cash-out refinance. Two months PITI in reserves after closing.

Practically, a $2,400 ADU rent adds about $1,800 a month, or $21,600 a year, of qualifying income. On San Diego pricing, that is a meaningful change in what you can buy.

The ADU has to be legal. Rental income from an unpermitted ADU generally cannot be used. FHA requires the appraisal to confirm legal rentability. If you are buying a house because the back unit pays the mortgage, and that back unit turns out to be unpermitted, your financing math collapses at underwriting. Verify permit status before you remove contingencies, not after.

For building rather than buying, the common paths are cash-out refinance, HELOC, construction or renovation loans such as FHA 203(k), and dedicated ADU financing products. Rules and availability change, so talk to a lender who has actually closed ADU projects in San Diego rather than one who has read about them.

The short-term rental trap

You cannot Airbnb a San Diego ADU. The Municipal Code requires that an accessory dwelling unit not be leased for fewer than 31 consecutive days, and the City's Short-Term Residential Occupancy FAQ states plainly that ADUs are prohibited from short-term rental. JADUs likewise must be rented for more than 30 days. The City describes a narrow exception for companion units permitted before October 15, 2017, and there were only about a hundred of those.

This matters because a meaningful share of buyers model an ADU at nightly rates and get a number that justifies the purchase. That model is not available. Build your underwriting on long-term rent, which is what the financing programs above will use anyway.

If short-term rental income is central to your plan, read the San Diego STR licensing rules before you buy anything, because the constraints there are tighter than most investors expect.

Unpermitted ADUs, and why AB 2533 changed the calculus

Walk through enough San Diego properties and you will find converted garages, back houses, and "bonus rooms" with a kitchen and a shower that never saw a permit. Historically that was a problem with no clean fix: no financeable rental income, insurance complications, and the risk of a code enforcement action if a neighbor complained.

AB 2533, effective January 1, 2025, changed that materially.

What the law does. It expands California's amnesty pathway for unpermitted ADUs and JADUs built before January 1, 2020. Local agencies must evaluate these units against habitability and safety standards rather than requiring full current building code compliance, and owners are generally exempt from retroactive impact fees, connection fees, and capacity charges. In practice that often means a safety inspection and modest corrective work instead of a demolition order or a gut rebuild.

Here is why that matters commercially. A property with a decent unpermitted back unit built in, say, 2012 is frequently priced as though that unit is worthless or a liability, because most buyers and most agents treat it that way. If there is a realistic legalization path, the gap between the price and the post-legalization value is the opportunity.

Do not buy on an assumption. Amnesty is a pathway, not a guarantee. The unit still has to meet habitability and safety standards, the pre-2020 construction date has to be establishable, and some units are too far gone or too poorly sited to save. Costs to correct can be significant. Before you write an offer on a property whose value depends on legalizing an unpermitted unit, get a contractor and, where warranted, a land use professional to look at it, and confirm the City's current process. The upside is real. The downside is buying a shed with plumbing.

Selling an ADU separately

This is one of the most misunderstood topics in San Diego right now, because the answer is different depending on which side of a jurisdiction line the property sits on.

WhereCan an ADU be sold separately?
Unincorporated San Diego County Yes, under an opt-in condominium program the Board of Supervisors adopted March 4, 2026, aligning with state law AB 1033. Effective April 2026.
City of San Diego ADUs built under the ADU Home Density Bonus Program can be sold individually rather than only rented. This is a separate mechanism from the County's AB 1033 program, and it is tied to the bonus program.
Other cities in the county AB 1033 is opt-in, so each jurisdiction decides independently. Check the specific city.

Where separate sale is available it is not a simple subdivision. Under AB 1033 the property goes through condominium mapping, must comply with the Davis-Stirling Common Interest Development Act and portions of the Subdivision Map Act, requires written lienholder consent, and generally requires forming a homeowners association.

That lienholder consent line is the one that stops most projects. Your existing lender has to agree to let a piece of its collateral be carved off and sold. Some will. Many will not.

Treat separate sale as a real but complex option, not a given, and price a property on its rental value unless you have confirmed the conversion path with a lender and a real estate attorney.

Buying a property that already has an ADU

This is where I spend most of my time, and where the expensive mistakes happen.

  1. Verify the permit, do not trust the listing. "Permitted ADU" in remarks is a claim, not a record. Pull the permit history from the City. An unpermitted unit changes financing, insurance, appraised value, and your ability to legally collect rent.
  2. Check the permit date against the STR rules. An ADU permitted after October 15, 2017 cannot be short-term rented, regardless of what a seller tells you about what they have been doing.
  3. Confirm the zone and the overlays. Coastal Overlay changes which rules apply. Very High Fire Hazard Severity Zone changes setbacks and bonus program eligibility. These are parcel-specific.
  4. Check whether it is actually an ADU. Guest quarters, converted garages without permits, and "bonus rooms with a kitchenette" are all different legal animals from a permitted ADU, and only one of them produces financeable rental income.
  5. If it is unpermitted, establish when it was built. A pre-2020 construction date opens the AB 2533 amnesty pathway and changes the property from a problem into a project. Post-2020 is a much harder conversation.
  6. Ask what else the lot could hold. On a multifamily property especially, the question is not only what exists but what the lot and zone would still allow. That is frequently where the value is.

What I do here. Send me an address and I will pull the permit history on any existing ADU, tell you which zone and overlays apply, and give you a realistic read on what else the lot could support. I am not an architect and I will not tell you a project is approvable, that is Development Services' call and a designer's analysis. What I can tell you is whether a property is worth paying a designer to look at, and that filter saves most of my clients a lot of time.

Common mistakes

  • Assuming every lot can take a detached ADU. Lot area, access, utility capacity and fire requirements all constrain it. Setbacks that allow building to the property line do not mean the site plan works.
  • Modeling nightly rates. Covered above. Not legal on ADUs.
  • Budgeting the structure and forgetting everything else. Site work, utilities, permits and soft costs regularly add $60,000 to $100,000 on top of the build number a contractor quotes.
  • Buying on an unverified permit. The single most expensive mistake on this list.
  • Ignoring the coastal distinction. If the parcel is in the Coastal Overlay Zone, several current ordinances may not apply to it yet.
  • Building the biggest ADU allowed. A 1,200 sq ft three-bedroom costs $450,000 and returns 5.6%. A garage conversion costs a fraction and returns nearly 10%. Bigger is not better here.
  • Not asking what the lot could still hold. Especially on 2-4 unit property, where the detached ADU allowance can double your door count.

Looking at a property with ADU potential?

Send me the address. I will pull the permit history, identify the zone and overlays, tell you what the detached ADU allowance would be for that parcel, and give you a straight answer on whether the numbers are worth pursuing. If you already own a 2-4 unit building and have never checked what else the lot allows, that is a fifteen minute conversation that occasionally changes everything.

Check a property's ADU potential

Common questions

How many ADUs can I build on a San Diego single-family lot?

In a single-dwelling zone, one attached or detached ADU, plus one converted ADU, plus one JADU. Under the ADU Home Density Bonus Program the total number of ADUs and JADUs is capped at 4 for lots up to 8,000 sq ft, 5 for 8,001 to 10,000 sq ft, and 6 for lots over 10,000 sq ft, with additional location, fire, parking and fee requirements.

Can I add ADUs to a duplex, triplex or fourplex?

Yes. On an existing multi-unit building in a multiple-dwelling zone, the City allows up to eight detached ADUs, not to exceed the number of existing units. So a fourplex can add up to four detached ADUs. You can also convert non-habitable space into ADUs at 25% of the existing unit count, minimum one. Attached ADUs are not permitted in this scenario, and JADUs are not permitted unless a previously conforming single dwelling exists.

Does a San Diego ADU require parking?

Generally no parking is required outside the Coastal Overlay Zone. Inside the Coastal Overlay Zone, one space may be required in the Beach Impact Area, with exemptions including units of 500 sq ft or less and attached units. Under the ADU Bonus Program, one space per affordable or bonus ADU is required outside a Transit Priority Area. Replacement parking is generally not required when converting a garage.

Do I have to live on the property?

Not for an ADU. Owner occupancy is not required. It is required for a JADU, with limited exceptions, and a recorded Junior Unit Agreement is required.

Can I rent my San Diego ADU on Airbnb?

No. The Municipal Code requires that an ADU not be leased for fewer than 31 consecutive days, and the City's STRO materials state ADUs are prohibited from short-term rental. JADUs must likewise be rented for more than 30 days. A narrow exception exists for companion units permitted before October 15, 2017.

What does an ADU cost to build in San Diego?

All-in costs in 2026 are running roughly $300,000 for a 500 sq ft one-bedroom, $350,000 for 750 sq ft, and $450,000 for a 1,200 sq ft three-bedroom, which works out to roughly $375 to $600 per square foot depending on size. Garage conversions are substantially cheaper. Small units cost more per foot because kitchen and bathroom costs do not scale down.

Can I use ADU rental income to qualify for a mortgage?

Yes, on a one-unit primary residence. Fannie Mae, Freddie Mac and FHA each allow 75% of lease or market rent, capped at 30% of qualifying income, with program-specific conditions. The ADU generally must be legal and rentable. Income from an unpermitted ADU typically cannot be used.

Can an ADU be sold separately from the main house?

It depends on jurisdiction. In unincorporated San Diego County, the Board of Supervisors adopted an opt-in AB 1033 condominium program on March 4, 2026, effective April 2026. In the City of San Diego, ADUs built under the ADU Home Density Bonus Program can be sold individually. Either path requires condominium mapping, Davis-Stirling compliance, written lienholder consent, and generally an HOA. A JADU cannot be sold separately from the primary dwelling.

Can I legalize an unpermitted ADU in San Diego?

Often yes, if it was built before January 1, 2020. AB 2533, effective January 1, 2025, expanded California's amnesty pathway so local agencies evaluate these units against habitability and safety standards rather than full current building code, and owners are generally exempt from retroactive impact, connection and capacity fees. It is a pathway rather than a guarantee, and corrective work can still be significant, so have a contractor assess the unit before you rely on it.

How long does an ADU permit take in San Diego?

With a pre-approved plan set, a complete detached ADU application carries a 30-day statutory decision clock under Government Code 65852.27, with permit issuance commonly running 60 to 90 days once corrections are included. Construction then typically takes 4 to 6 months, putting total time to occupancy and first rent at roughly 6 to 12 months. Custom designs add 8 to 16 weeks of design plus a longer plan check, for 8 to 16 months total. As of January 1, 2026, SB 543 also requires the City to make a completeness determination within 15 days or the application is deemed complete.

Do I pay impact fees on a San Diego ADU?

Development Impact Fees apply to ADUs, and generally become a factor above 750 sq ft. As of January 1, 2026, SB 543 exempts ADUs and JADUs under 500 sq ft from school impact fees. The General Plan Maintenance Fee applies to all ADUs and JADUs. Projects with more than one ADU also pay Regional Transportation Congestion Improvement Program fees. Confirm current fee schedules with Development Services, since these change.

Does an ADU increase my property taxes?

The new construction is assessed and added to your assessed value. The existing home is not reassessed. The practical effect is a property tax increase tied to the value of the improvement, which is why the return calculations above assume operating costs that include it. Confirm specifics with the County Assessor and your CPA.

Related

Sources

  • City of San Diego Information Bulletin 400, Accessory Dwelling Unit / Junior Accessory Dwelling Unit, January 2026 edition
  • City of San Diego Short-Term Residential Occupancy, ADU prohibition
  • San Diego Municipal Code 141.0302(a)(8), accessory dwelling unit minimum rental term
  • San Diego City Council action of June 16, 2025, amendments to the ADU Home Density Bonus Program
  • San Diego ADU cost data, builder-published 2026 figures
  • Fannie Mae Selling Guide, Freddie Mac Seller/Servicer Guide, and FHA Mortgagee Letter 2023-17, ADU rental income eligibility
  • California SB 543 (2025), effective January 1, 2026: 15-day completeness determinations and school impact fee exemption for ADUs and JADUs under 500 sq ft
  • California AB 1154 (2025), effective January 1, 2026: JADU owner-occupancy limited to units sharing sanitation facilities
  • California AB 462 (2025), effective October 15, 2025: 60-day decision requirement for ADU Coastal Development Permits
  • California AB 253 (2025) and AB 1308 (2025): private plan check and inspection timing for small projects
  • California AB 2533 (2024), effective January 1, 2025: amnesty pathway for unpermitted ADUs and JADUs built before January 1, 2020
  • California AB 1033 (2023), separate conveyance of ADUs, and the San Diego County Board of Supervisors ADU Ordinance Amendment adopted March 4, 2026 for unincorporated areas
  • California Government Code 65852.27, 30-day decision requirement for detached ADUs using pre-approved plans

About the author

🏆 RealTrends Verified 2025 - #4 in San Diego by transactions | #7 by volume
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200+ families served | 350+ units closed | $250M+ in transactions | DRE# 02026495

San Diego native, duplex and ADU specialist, and a house hacker myself. I work on 2-4 unit and ADU property here every week, which is why this page leads with the multifamily detached allowance instead of burying it.

Twana Rasoul, DRE# 02026495 | Compass | 619.792.8295 | twana.rasoul@compass.com
8889 Rio San Diego Dr., Ste #200, San Diego, CA 92108

This page is general information for San Diego property owners and investors. It is not legal, tax, engineering, or construction advice, and no advisor relationship is created by reading it. I am a real estate agent, not an architect, contractor, land use attorney, or lender, and I do not make determinations about permit eligibility, code compliance, or project feasibility. Regulations change frequently and several ordinances referenced here are not yet effective in the Coastal Overlay Zone. Cost and rent figures are illustrative market estimates, not quotes. Verify all requirements with the City of San Diego Development Services Department and consult licensed professionals before buying or building.