San Diego Pre-Approved ADU Plans (2026): All 26 Options Compared

San Diego pre-approved ADU plans save real time and meaningful money for the right homeowner — and quietly fail for the wrong one. The City of San Diego’s Development Services Department (DSD) currently accepts three pre-approved ADU plan libraries: the County of San Diego Standard ADU Plans (6 plans, free download), the City of Chula Vista Standard ADU Plans (12 standard options designed by SnapADU, designer-licensed), and the City of Encinitas Permit-Ready ADU Plans / PRADU (8 plans by Design Path Studio and DZN Partners, free download). The San Diego Housing Commission also publishes 4 template sets that received initial DSD approval — usable inside City limits but not on DSD’s accepted-source list. That’s 26 official plan options across the three currently listed City-accepted sources (City of San Diego DSD, ADU/JADU page, verified May 8, 2026).

Under California Government Code §65852.27 (added by AB 1332 and recodified by SB 477, effective March 25, 2024), a complete permit application for a detached ADU using a qualifying pre-approved plan shall be approved or denied within 30 days (CA Government Code §65852.27). Realistic upfront savings on design and plan-check work land in the $5,500–$18,000 range. All-in build cost still runs $300,000–$450,000 for most detached units. Time saved on the design and plan-check phases is typically 2–4 months for projects that fit without modification.

This page is the consolidated decision tool we built so you don’t have to open ten tabs to figure out which plan applies to your lot, what the 30-day rule actually delivers, and whether a pre-approved plan is the right move at all.

What is a pre-approved ADU plan, exactly?

A pre-approved ADU plan (sometimes called a permit-ready or standard plan) is a complete architectural plan set that a city or county has already reviewed for general code compliance and posted publicly so any homeowner can use it as the starting point for a permit application. The plan is not site-specific — the local agency reviewed the building itself, not your lot. You still have to layer in your property-specific information (site plan, foundation engineering, utility tie-ins, energy compliance) before the permit package is complete.

A few terms we’ll use throughout

ADU (Accessory Dwelling Unit):

A self-contained living unit on the same lot as a primary residence, with its own kitchen, bath, and sleeping area. In San Diego it can be 150 to 1,200 square feet.

JADU (Junior Accessory Dwelling Unit):

A unit no larger than 500 square feet contained within an existing single-family residence, with kitchen and (usually shared) bath.

Detached ADU (or DADU):

A standalone structure separate from the primary house. This is the type AB 1332's 30-day rule covers.

Attached ADU:

Shares one or more walls with the primary house.

Plan check:

The city's review of your permit drawings for code compliance.

Site work:

Grading, excavation, drainage, and utility connections specific to your lot.

Setback:

The minimum legal distance between a structure and a property line.

FAR (Floor Area Ratio):

The ratio of total floor area to lot size.

Ministerial approval:

A permit decision made on objective criteria with no public hearing or discretionary review.

Triennial code cycle:

California adopts a new Building Standards Code every three years; the current cycle is the 2025 California Building Standards Code, effective January 1, 2026.

CDP (Coastal Development Permit):

Permit required for development in California's Coastal Zone.

Which San Diego pre-approved ADU plans does the City accept?

The City of San Diego’s Development Services Department accepts pre-approved ADU plans from three sources: County of San Diego Standard ADU Plans, City of Chula Vista Standard ADU Plans, and City of Encinitas Permit-Ready ADU Plans (PRADU). Plans from other San Diego County cities are not on the City of San Diego’s current accepted-source list unless DSD later adds them. The San Diego Housing Commission separately publishes 4 template sets that received initial DSD approval and can be used inside City limits, but they are not part of the DSD pre-approved-plan list and require additional site-specific review.

The 3-library snapshot

Total publicly posted, City-accepted plan options: 26.

Sources: City of San Diego DSD ADU/JADU page; San Diego County PDS Dwelling Unit Building Plans; City of Chula Vista DSD ADU page; City of Encinitas ADU page. All verified May 8, 2026.

All 26 plans compared (the master inventory)

Below is the full inventory of every pre-approved ADU plan currently accepted by the City of San Diego, with sizes, layouts, designer of record, cost to use, and a direct link to the official source page so you can verify each plan and download files yourself. Where the underlying source page does not date-stamp its inventory, we recommend a quick verification step before you commit money to any path.

County of San Diego Standard ADU Plans (6 plans, free)

The County of San Diego Planning & Development Services (PDS) publishes a set of dwelling unit building plans available for free download in 36″×24″ PDF, 17″×11″ PDF, and CAD (.dwg) formats. The County states its own plans are approximately 85% complete and require project-specific information before submittal (San Diego County PDS Dwelling Unit Building Plans, verified May 8, 2026). The City of San Diego separately accepts these plans for use inside City limits. Plans G (1,728 sq ft) and H (1,500 sq ft) are designated single-family-dwelling-only and cannot be used as ADUs because they exceed the 1,200 sq ft maximum.

View official source: San Diego County PDS — Dwelling Unit Building Plans →

The cost-savings angle on County plans is real but narrow: the PDF and CAD files are free, so you skip the architectural design fee entirely (typically $8,000–$15,000 in San Diego). What you still pay for: a draftsperson or designer to produce your site-specific package, structural calculations tied to your foundation, Title 24 energy compliance, geotechnical work where required, and any modifications you need to make the plan work on your lot.

City of Chula Vista Standard ADU Plans (12 plans, designer-licensed)

The City of Chula Vista contracted with SnapADU through a competitive bid process to produce its Standard ADU Plan library. The plans are organized as six base layouts, each available in a standard orientation and a reversed (mirror) orientation — for 12 total plan-orientation combinations.

View official source: City of Chula Vista — Accessory Dwelling Units → Sources: City of Chula Vista DSD ADU page; SnapADU plans page. Verified May 8, 2026.

Chula Vista’s plans require a license arrangement with the designer (SnapADU) before you can use them. Public statements suggest licensing budget in the $1,500–$4,000 range depending on which base plan, level of customization, and whether a build contract follows; we recommend confirming the current fee directly with SnapADU before relying on this number.

The City of San Diego accepts these plans for in-City use; you would still license them from SnapADU and submit a complete site-specific package to City of San Diego DSD. Inside Chula Vista city limits, the City’s own pre-approved review path delivers 14-business-day plan review and reduces plan-review fees by approximately $1,000 (City of Chula Vista DSD ADU page, verified May 8, 2026). Those Chula Vista–specific savings do not automatically transfer to City of San Diego projects.

City of Encinitas Permit-Ready ADU Plans / PRADU (8 plans, free)

The City of Encinitas’s Permit-Ready Accessory Dwelling Unit (PRADU) program started in 2019. The City contracted two local architectural firms — Design Path Studio and DZN Partners — and each produced four plan sizes: a studio, a 1-bedroom, a 2-bedroom, and a 3-bedroom unit. That’s 8 PRADU plans total. All eight are free to download and require designer attribution on the permit submittal.

View official source: City of Encinitas — Accessory Dwelling Units →

Sources: City of Encinitas DSD ADU/PRADU page; Design Path Studio Encinitas PRADU portfolio; The Coast News January 2019 program launch coverage. Verified May 8, 2026.

The two design firms took different philosophical approaches. Design Path Studio’s plans are intentionally expandable — the studio includes the full plumbing, electrical, and structural infrastructure needed for the 1-BR, 2-BR, and 3-BR variants, so a homeowner who can only afford the studio today can expand later without redoing utilities. DZN Partners’ plans emphasize exterior customization — extensive options for siding, roof lines, and window/door variations to match neighborhood character.

The smallest accepted pre-approved ADU plan in any of the three City-accepted libraries is the DZN Partners 224 sq ft studio. The largest is a tie at 1,200 sq ft (County Plans A, B, and C).

The City of Encinitas’s official PRADU page states its plans have been updated to current building code requirements (City of Encinitas ADU page, verified May 8, 2026). We still recommend a quick verification call to Encinitas Development Services confirming the specific plan is current under the 2025 California Building Standards Code before paying any drafting fees. The verification step: ask the city plan-check counter, “Is plan [name] still permit-ready under the 2025 California Building Standards Code?” Get the answer in writing.

San Diego Housing Commission ADU Templates (4 templates, City-only)

The San Diego Housing Commission (SDHC) developed four ADU template sets through its Pilot Program — built on five SDHC-owned single-family lots and refined into reusable plans ranging from studios to 3-bedroom units with customization options. SDHC says these plans received initial approval from the City of San Diego DSD but still require site-specific review. SDHC also makes clear it cannot authorize use of these plans outside the City of San Diego (San Diego Housing Commission ADU page, verified May 8, 2026).

View official source: San Diego Housing Commission — ADU page →

The SDHC templates are worth knowing about for two reasons. First, they are an additional City-of-San-Diego-only source of pre-developed plans — useful if none of the County, Chula Vista, or Encinitas plans fit your design goals. Second, SDHC also runs an ADU Finance Program offering construction-to-permanent loans up to $250,000 to moderate-income City of San Diego homeowners, with a 7-year affordability commitment. We cover that in the financing section below.

Are San Diego pre-approved ADU plans still valid under the 2025 code cycle?

This is the question most pages dance around. Here’s the direct answer with each library’s current status.

The 2025 California Building Standards Code took effect for permit applications received on or after January 1, 2026. AB 1332’s 30-day shot clock applies to a pre-approved plan only when that plan is current under the triennial California Building Standards Code rulemaking cycle — which is now the 2025 cycle. Plans drawn under the prior 2022 cycle do not automatically remain compliant.

Code-cycle status table (City-accepted libraries)

The 60-second verification step

Before you pay anyone for site-specific work tied to a specific pre-approved plan:

1. Call the city DSD plan-check counter (City of San Diego DSD, City of Encinitas Development Services, or San Diego County PDS, depending on which plan you’re using).
2. Ask: “Is the [Plan A from County / 749 Square from Chula Vista / Design Path Studio 2-BR PRADU] currently permit-ready under the 2025 California Building Standards Code, or has it been flagged for update?”
3. Get the answer in writing (email is fine).
4. If the city says the plan is current, move forward. If not, either wait for the city’s update, retain the original designer to update it under contract, or pivot to a semi-custom path.

That single phone call protects you from the most expensive failure mode of the pre-approved plan path: paying for soils, energy compliance, and structural work tied to a plan the city will reject in plan check.

AB 1332 and the 30-day shot clock — how it really works

Government Code §65852.27 (added by AB 1332 and recodified by SB 477, effective March 25, 2024) requires every California city and county to run a program for pre-approving ADU plans, and requires local agencies to approve or deny a complete detached-ADU permit application within 30 days when the application uses a qualifying pre-approved plan. The 30-day rule applies only to detached ADUs, only on a complete application, and only when the plan is current under the triennial California Building Standards Code rulemaking cycle. Misunderstanding any of those three conditions is how homeowners end up frustrated when their “30-day permit” sits in plan check for six weeks.

What the statute actually says (in plain English)

Government Code §65852.27 mandates the 30-day approve-or-deny window when an application uses one of two qualifying types (CA Government Code §65852.27):

1. A plan that has been preapproved by the local agency within the current triennial California Building Standards Code rulemaking cycle, or
2. A plan identical to a plan already used in an approved detached ADU application by the same local agency within the current triennial code cycle.

First, the clock applies only to detached ADUs. Attached ADUs and JADUs are not covered — they are processed under Government Code §§66317 and 66320 (the recodified ADU/JADU framework), which give local agencies 60 days to act on a complete application. Second, the clock starts only when the application is complete. Submitting a half-finished package doesn’t start the 30 days. Third, the plan has to be current under the triennial cycle.

The Coastal Overlay Zone exception — and the AB 462 update most pages miss

For ADU projects in the Coastal Overlay Zone, a Coastal Development Permit (CDP) may be required. Assembly Bill 462 (2025) changed how CDPs work for ADUs: ADU coastal development permit applications must generally be approved or denied within 60 days of a complete application and processed concurrently with the ADU application (CA AB 462 bill text, verified May 8, 2026). That’s a significant improvement over the historical 3–6 month CDP processing baseline, but it doesn’t eliminate the CDP requirement itself, and the 60-day CDP clock doesn’t replace the AB 1332 30-day window. Coastal Overlay Zone homeowners should plan for the longer of the two timelines and verify their specific project’s CDP requirement with the City (City of San Diego Information Bulletin 400).

What “30-day approval” doesn’t mean

Are these plans really permit-ready?

No. A pre-approved ADU plan is approximately 80% of what your permit submittal needs and only about 30% of what your project needs. That ratio is our editorial framework based on standard San Diego ADU project breakdowns — not a number from a single source. The plan covers the building itself: floor plans, elevations, structural and energy basics for a generic version of the unit. Your permit application still requires a property-specific package on top of that. And your project — the 6-to-12-month, $300,000+ effort to actually build the thing — looks identical regardless of whether you started with a pre-approved plan or a custom one.

Methodology note for the 80%/30% framework: We allocate the 80% on the permit-submittal side based on the City of San Diego’s published Information Bulletin 400 minimum submittal list — most architectural drawings, structural details, and code-compliance scaffolding are covered by the pre-approved plan, while site-specific items remain. The 30% on the project side reflects that design and plan check are roughly one-quarter to one-third of total project effort and budget. The 80/30 framework is editorial, not a primary-source statistic.

What the pre-approved plan actually covers

• Generic floor plan and dimensional drawings
• Elevation drawings (the building's exterior appearance)
• Architectural sections
• Standard structural details (typical foundation, framing, roof system)
• Code-compliant kitchen and bath layouts
• Generic energy-compliance scaffolding (still requires project-specific update)
• Plumbing, electrical, and mechanical layout templates
• Some specifications and material schedules

What you still produce yourself (the site-specific package)

Per City of San Diego DSD Information Bulletin 400 and the City’s standard submittal requirements. Verify geotechnical requirements with your reviewing agency.

The honest math: real net savings (with methodology)

The realistic upfront net savings band for a homeowner who doesn’t modify the plan is $5,500–$18,000 — based on the worked methodology below. This range applies to a typical City of San Diego project.

Sources: SnapADU April 2026 cost guide; City of San Diego DSD Information Bulletin 501 (fee schedule); regional 2026 design-build cost data from multiple San Diego builder publications; The Coast News Encinitas PRADU launch coverage (2019, baseline range). Verified May 8, 2026.

Damaging admission

A pre-approved ADU plan is not a cheat code, and we’re not going to pretend it is. On a flat suburban lot with standard utilities and a homeowner whose goals match a published layout, the path saves real time and real money — typically two to four months on the design and plan-check phases, and somewhere between $5,500 and $18,000. On a sloped lot, a coastal-zone property, a fire-zone parcel, a lot with complex utility extensions, or any project where the homeowner wants meaningful design customization, starting from a pre-approved plan can be slower and more expensive than a semi-custom design from the beginning. Multiple San Diego builders publicly note that real-world permit timelines for PRADU plans are often not faster than custom plans when modifications are common.

The good news: if you fit the profile where it does work, this is one of the cleanest cost-and-timeline wins available to a San Diego homeowner today, and the Encinitas PRADU program’s first-year statistics showed roughly 25% of all Encinitas ADU permits used PRADU plans — meaningful adoption from informed homeowners.

What fees still apply if I use a pre-approved ADU plan?

The pre-approved plan path doesn’t change the fee structure. You still pay City permit fees, plan-check fees, capacity charges, and (above the size thresholds) impact fees, school fees, and any applicable affordable-housing fees. Here is how the categories actually break down.

The fee categories explained

Sources: City of San Diego IB 400 and IB 501; California Senate Bill 13. Verified May 8, 2026.

The plan-size decision that actually moves fees

The single biggest fee decision a homeowner makes is plan size, not plan source.

• At or under 500 sq ft: Both school fees and impact fees are typically waived. Encinitas DZN Partners 224 and 499 sq ft and County Plan F at 600 sq ft (school exemption applies through 500 sq ft) are the smallest-fee-footprint options.
• At or under 750 sq ft: Impact fees waived under SB 13. School fees may apply but the impact-fee waiver alone typically saves $5,000–$15,000 in San Diego per the City’s published fee context.
• Over 750 sq ft: Full impact fees apply, calculated proportionally per current state rules; school fees apply over 500 sq ft.

How much money can a pre-approved ADU plan actually save?

The honest answer is $5,500–$18,000 in upfront design and plan-check work for a homeowner whose lot and goals fit the plan without major modification — the worked range above. The pre-approved plan does not reduce construction cost, impact fees (which are tied to plan size, not source), school fees, capacity charges, utility connection costs, or inspection fees. All-in construction cost for a typical detached ADU in the City of San Diego in 2026 lands at $300,000–$450,000, and the smaller pre-approved options can land at $250,000–$320,000 for a 600–800 sq ft unit on a clean lot — based on multiple regional design-build cost publications cross-referenced for 2026.

Methodology note: All-in cost ranges in this guide are Dwelling Index estimates triangulated from publicly available 2026 cost data published by San Diego design-build firms (SnapADU, Streamline Design Group, Better Place Design + Build) cross-referenced against the City’s published IB 501 fee schedule and current builder quote ranges. They are estimates, not guarantees. Verified May 8, 2026.

For a complete walk-through of which financing lane fits which homeowner, see our ADU Financing Options guide and the dedicated HELOC for ADU guide.

Financial disclaimer: These are educational examples, not guarantees of approval, rates, payments, or returns. Actual options depend on property value, equity, credit profile, income, construction scope, lender requirements, and local approvals.

Can you modify a pre-approved ADU plan?

You can — but if you do, the plan typically loses its pre-approved status and your application no longer qualifies for the AB 1332 30-day review window. The City of Encinitas states this directly: changes to a pre-approved PRADU plan disqualify it from pre-approved review and the application reverts to standard ADU plan check (City of Encinitas ADU page, verified May 8, 2026). The other accepted libraries follow the same logic. In practice, “modify” usually means the plan goes back into standard plan check timelines, you pay a redraw fee of $2,000–$4,000, and the design becomes a custom plan dressed in pre-approved scaffolding — often the worst of both worlds.

What modifications break pre-approval

• Changing the building footprint (length, width, or shape)
• Adding or removing a bedroom, bathroom, or kitchen
• Significantly relocating plumbing or major electrical
• Changing roof form or pitch in ways that affect structural calculations
• Anything structural — beams, posts, foundations, lateral systems
• Combining elements from two different pre-approved plans

What modifications may be tolerated (verify with the city before relying on this)

• Cosmetic finishes (siding color, roofing material) where the plan documents include menu options
• Window/door swaps where the rough opening dimensions and structural framing don't change
• Some interior finish choices (flooring, cabinets, fixtures) that don't affect plan check
• Encinitas Design Path Studio plans are specifically designed to be expanded over time — but the expansion still requires its own permit

The verification rule is simple: any change that’s not explicitly listed as a customization option in the plan documents themselves should be checked with the city’s plan-check counter before you commit money. Email is fine. Get the answer in writing.

When to walk away from the pre-approved path

If you’ve identified more than two modifications you need to make a plan work for your lot or your goals, the math usually flips toward semi-custom. A semi-custom path takes the same total timeline as standard plan check, costs roughly the same as a heavily-modified pre-approved plan, but produces a building actually optimized for your site. The honest read: pre-approved plans are a niche tool that fits well-prepared homeowners on standard lots with standard goals. They are not the default starting point for every San Diego ADU project, even though much of the marketing implies otherwise.

Will the pre-approved plan work for your specific lot?

For a meaningful share of San Diego homeowners considering an ADU, yes. For many others, lot conditions or design goals make a semi-custom path a better fit. The deciders are five lot conditions — Coastal Overlay Zone, Very High Fire Hazard Severity Zone, slope, setback geometry, and utility distance — plus your design goal. When any of those conditions is present, the AB 1332 30-day shot clock often doesn’t apply or doesn’t help as much as the marketing implies, even though the pre-approved plan itself is still legal to use.

The override matrix

The Coastal Overlay Zone reality check

The Coastal Overlay Zone covers significant parts of the City of San Diego (Pacific Beach, La Jolla, Mission Beach, Ocean Beach, parts of Point Loma) and surrounding cities. The big 2026 update most pages haven’t caught up with: AB 462 set a 60-day approve-or-deny clock on ADU CDP applications, processed concurrently with the ADU application. That’s a meaningful improvement over the historical baseline, but it doesn’t eliminate the CDP requirement itself, and the AB 1332 30-day clock does not override the CDP timeline. Coastal-zone homeowners should plan for the longer of the two timelines. For coastal-zone homeowners, the pre-approved plan path can still save money on design work, but it won’t deliver a 30-day permit — plan accordingly.

Very High Fire Hazard Severity Zone considerations

For parcels in a Very High Fire Hazard Severity Zone, the 4-foot side and rear setback minimum applies regardless of building height per City IB 400. Defensible-space requirements (clearing vegetation around the structure, fire-resistant landscaping) layer on top. Detached ADUs are exempt from fire sprinkler protection if the primary dwelling is not sprinkler-protected and the ADU qualifies as a Group R-3 occupancy; ADUs built under the Home Density Bonus Program require automatic sprinkler systems regardless. None of that is covered by a pre-approved plan; all of it is site-specific work the homeowner pays for.

The 4-Filter Decision Framework

If you can pass these four filters in order, a pre-approved ADU plan is likely the right call for your project. If any filter fails, follow the alternative path noted. We built this framework specifically to resolve the active-planning homeowner’s central question: “Should I do this, or am I better off going semi-custom?”

Filter 1: Is your jurisdiction served?

If your property is in the City of San Diego, the three accepted plan libraries are: County of San Diego, City of Chula Vista, and City of Encinitas — plus the SDHC templates as a separate City-only source.

If your property is in unincorporated San Diego County, the County’s six standard plans (A–F) are the natural starting point.

If your property is in any other San Diego County city — Chula Vista, Encinitas, Carlsbad, San Marcos, Escondido, El Cajon, La Mesa, Imperial Beach, Del Mar, Oceanside, Vista, Poway, Coronado, Solana Beach, Lemon Grove, National City, Santee — your city has its own program with its own accepted plans.

If this filter fails: Skip pre-approved. Go semi-custom with a local design-build firm. Design fees are similar, the design fits your lot, and you bypass any AB 1332 mismatch entirely.

Filter 2: Are the plans current under the 2025 Building Code cycle?

Verification step: call the city DSD plan-check counter or the listed designer of record for your chosen plan. Ask in writing whether the plan is currently permit-ready under the 2025 California Building Standards Code. Use the code-cycle status table above for current status by library.

If this filter fails: Either pay the designer to update the plan (often the cheapest semi-custom path because the designer already knows the geometry) or wait for the city’s update.

Filter 3: Will the plan fit your lot without modification?

Run our Property Eligibility Check or hire a feasibility consultant to confirm setback compliance, lot dimensions, and utility tie-in feasibility for your chosen plan on your specific lot. The most common failure mode here: a plan that fits within the buildable area on paper but requires utility extension that adds significant cost to the project, or a setback assumption that doesn’t match your zoning.

If this filter fails: Semi-custom. You’ll keep some cost benefits without the headache of trying to force a misfit plan through the AB 1332 30-day path.

Filter 4: Does the design meet your primary goal?

If this filter fails (no plan matches your goal): Semi-custom. The cost of a non-optimized plan over 10–30 years of use almost always exceeds the upfront design-fee savings.

Pass all four filters?

Pre-approved is the right call. Move to the step-by-step permit path below.

The honest distribution

Based on regional lot-condition prevalence (Coastal Overlay Zone reach across coastal communities, VHFHSZ across hillside neighborhoods, and the share of San Diego County lots with slope or irregular geometry), our editorial estimate is that a pre-approved plan is a clean fit for roughly one-third of homeowners considering an ADU and a poor fit for the remaining majority. The pre-approved plan path is overhyped in its marketing as the default; in practice it’s a focused tool that works very well for a specific homeowner profile and overpromises for the rest.

When pre-approved makes sense — and when it doesn’t

These are illustrative scenarios for decision pattern-matching, not verified case studies; cost and timeline assumptions are rounded estimates from the methodology elsewhere on this page.

Three illustrative scenarios where pre-approved is genuinely the best call

Three illustrative scenarios where pre-approved is the wrong call

If your gut says “I just want a clean small ADU done in the standard way” — pre-approved is your tool. If your gut says “I want this thing to be exactly right for my lot/goals” — semi-custom is your tool. Don’t fight your gut for a $5,500–$18,000 upfront savings figure.

How to use a pre-approved ADU plan in the City of San Diego: step-by-step

The shortest path from plan selection to permit issuance using a pre-approved ADU plan in the City of San Diego is typically 60–90 days in our editorial estimate when no Coastal Development Permit is required, and the AB 1332 30-day clock starts only on a complete application.

The 10-step path

1. Confirm your property is in the City of San Diego (and not unincorporated County or another city). Use ZAPP (Zoning and Parcel Information Portal) to verify jurisdiction.
2. Select your plan from one of the three accepted libraries. Use the master inventory above. Match plan size to your lot’s buildable area and your goal.
3. Verify code-cycle compliance with the city. Call the DSD plan-check counter. Ask in writing whether the plan is current under the 2025 California Building Standards Code. Get the answer documented before you spend money. Use the code-cycle status table above as your starting point.
4. Contact the plan designer of record if licensing is required. For Chula Vista plans, this means contacting SnapADU and signing a license agreement. For County and Encinitas plans, this means including the designer attribution on your permit submittal. For SDHC templates, contact SDHC directly at adu@sdhc.org.
5. Hire a draftsperson or designer to produce the site-specific package. This is the homeowner’s responsibility. The package includes site plan, vicinity map, soils/geotechnical report (where required for your jurisdiction and project size), structural calculations, foundation engineering, Title 24 energy compliance, utility tie-in plans, and any required forms (DS-3032, DS-16, DS-560, JADU agreement if applicable).
6. Compile the full submittal. Use City of San Diego DSD Information Bulletin 400 as the master checklist. Cross-check that you have every item before submission.
7. Submit a complete application to City of San Diego DSD. Submission is electronic via the City’s permit portal. The 30-day AB 1332 clock starts on a complete submission.
8. Pay plan-check fees, impact fees (if applicable above 750 sq ft), school fees (if applicable above 500 sq ft), and capacity charges. Reference Information Bulletin 501 for the current fee schedule.
9. Address corrections during plan check. Even with a pre-approved plan, plan check almost always returns at least one round of corrections — usually on site-specific items like utility tie-ins or stormwater compliance. Respond promptly to keep the clock running.
10. Receive permit issuance, build, and final inspections. Construction typically runs 4–8 months for a detached ADU once permits are in hand. Final inspections cover building, electrical, plumbing, mechanical, and fire if applicable.

Realistic timeline by phase (Dwelling Index editorial estimates)

Timeline ranges are Dwelling Index editorial estimates triangulated from regional builder publications; verify your specific project timeline with your reviewing agency and selected builder.

Build cost and rental income reality

A typical detached ADU using a pre-approved plan in the City of San Diego in 2026 costs $300,000–$450,000 all-in (construction + soft costs + site work + permits) — based on multiple regional design-build cost publications cross-referenced for 2026. The construction cost does not vary meaningfully based on whether you started from a pre-approved plan or a custom design.

All-in cost ranges (Dwelling Index estimates triangulated from 2026 sources)

Sources: SnapADU 2026 cost guide; Streamline Design Group San Diego ADU cost data 2026; Better Place Design + Build 2026 cost data. Verified May 8, 2026.

Illustrative rental benchmarks for ADU-sized units

These ranges describe rental benchmarks for ADU-sized units across much of the City of San Diego — derived from broader San Diego rental market data, not exclusively from ADU-only comparable sets.

Sources: 2026 San Diego rental market data including Rentometer average rent benchmarks and other 2026 regional rental publications; ranges adjusted for ADU-typical unit sizes. Coastal-proximity submarkets trend toward the high end. Verified May 8, 2026.

Disclaimer: These are illustrative examples, not guarantees of returns. Actual results depend on local market conditions, ADU finishes, neighborhood, regulatory environment, and rental market trends.

The City of San Diego prohibits short-term residential occupancy (rental terms under 31 days) for ADUs and JADUs.

SDHC’s ADU Finance Program: the moderate-income financing path

The San Diego Housing Commission’s ADU Finance Program offers construction-to-permanent loans up to $250,000 plus free technical assistance to moderate-income City of San Diego homeowners building an ADU on their property. In exchange, the homeowner agrees to keep the ADU’s rents affordable to tenants earning up to 80% of Area Median Income (AMI) for seven years. The program funds one ADU per property and excludes rentals to family members during the affordability period (San Diego Housing Commission ADU page, verified May 8, 2026).

SDHC Finance Program criteria (verify current with SDHC)

• Property must be in the City of San Diego
• Owner-occupied primary residence required
• Income limits apply (verify current limits with SDHC; limits update annually)
• Minimum credit score required (current published threshold around 680; verify with SDHC)
• Application fee due at construction-loan closing
• Affordable rent restriction: 7 years, tenants up to 80% AMI
• Affordable rent definition: 30% or less of tenant's monthly household income

Source: San Diego Housing Commission ADU page. Verified May 8, 2026. Specific income limits, credit thresholds, and program availability are subject to change — always confirm current eligibility directly with SDHC at adu@sdhc.org before relying on these figures.

The program pairs especially well with the four SDHC ADU template plans because both are designed for the same homeowner profile: City of San Diego owner-occupants who want a streamlined path to building their first ADU. For homeowners who don’t fit SDHC’s income or owner-occupancy criteria, the alternative financing paths (cash-out refinance, HELOC, construction loan, home equity investment) are covered in our ADU Financing Options guide.

What we verified

This guide combines verified primary-source facts and clearly-labeled Dwelling Index editorial framework. We separate them transparently so you know what’s documented and what’s our analysis.

Verified against primary sources (verified May 8, 2026)

Labeled as Dwelling Index editorial framework or estimate

Claims attributed to a single source

We use this transparency standard so you can decide for yourself which claims to weight heavily. Last updated: May 8, 2026. Last verified: May 8, 2026. Next scheduled verification: August 8, 2026 (quarterly cadence).

Frequently Asked Questions

Methodology

The Dwelling Index is an independent research resource covering ADU financing, costs, and regulations. We are not a builder, a lender, a designer, or a broker. We don’t take pay-to-play placements. We do work with vetted partners (disclosed at every mention), and our editorial recommendations are independent of those partnerships.

This guide was assembled by:

1. Direct fetch and review of every primary source listed above on the verification date
2. Statutory analysis of California Government Code §65852.27, AB 1332 (Carrillo, 2023) as recodified within the current ADU framework by SB 477, AB 462 (2025), and supporting administrative guidance from SANDAG, California Building Officials (CALBO), and HCD's 2026 ADU Handbook
3. Cross-reference of each plan library's published inventory against the City of San Diego DSD's current accepted-plan list
4. Code-cycle compliance verification using the California Building Standards Commission's current cycle posting and current designer-of-record advisories
5. Cost-and-timeline triangulation across multiple 2026 San Diego builder publications, the City's published fee schedule (Information Bulletin 501), and regional rental market data, transparently labeled as Dwelling Index estimates rather than primary-source figures
6. Editorial framework built around the four-filter homeowner decision question, structured for active-planning readers who want to make a decision they won't regret

For our full editorial standards and corrections process, see /editorial-standards/ and /corrections/. For our partner vetting policy, see /partner-vetting-policy/.

Source notes

Primary sources consulted for this guide (all verified May 8, 2026):

1. City of San Diego Development Services Department, Accessory Dwelling Unit / Junior Accessory Dwelling Unit page
2. City of San Diego Development Services Department, Information Bulletin 400 (Accessory Dwelling Unit permit guidance)
3. City of San Diego Development Services Department, Information Bulletin 501 (fee schedule)
4. City of San Diego Development Services Department, Information Bulletin 114a (master plan production process)
5. San Diego County Planning & Development Services, Dwelling Unit Building Plans
6. City of Chula Vista Development Services Department, Accessory Dwelling Units page
7. City of Encinitas Development Services, Accessory Dwelling Units / PRADU program page
8. California Government Code §65852.27 (added by AB 1332, recodified within the current ADU framework by SB 477)
9. California AB 462 (2025) (60-day Coastal Development Permit clock for ADUs, concurrent processing)
10. SnapADU, San Diego pre-approved ADU plans guide (April 2026)
11. Design Path Studio, City of Encinitas PRADU portfolio
12. The Coast News, Encinitas PRADU program launch coverage (January 2019)
13. San Diego Housing Commission, ADU page
14. City of Carlsbad ADU Permit-Ready Program page
15. San Diego Municipal Code Chapter 14, Article 1, Division 3 (ADU regulations); §131.0422 (zone setbacks); §141.0302 (ADU regulations and home density bonus)
16. California Department of Housing and Community Development (HCD), 2026 ADU Handbook
17. California Building Standards Commission (2025 California Building Standards Code rulemaking cycle)
18. Regional 2026 cost data: Streamline Design Group; Better Place Design + Build
19. Rental benchmark data: Rentometer and other 2026 regional rental publications

Related guides

• Real San Diego ADU all-in cost ranges
• How to finance the $300K–$450K all-in cost
• HELOC route for ADU construction
• The City's accepted pre-approved ADU plan libraries
• The City Standard ADU plan path explained
• The Encinitas PRADU program inventory
• The County's six standard ADU plans
• How much does an ADU cost?
• Custom alternatives if a pre-approved plan doesn't fit
• Prefab ADU paths as an alternative to pre-approved site-built plans