Over the Counter vs Plan Check: Comparing ADU Approval Processes

Two Paths to ADU Approval: Which One Is Right for You?

When it comes to getting your ADU permitted in California, there are two fundamentally different approval pathways: over-the-counter (OTC) approval and standard plan check review. The path you take can mean the difference between a permit in hand within days versus a process that stretches over months.

Over-the-counter approval is exactly what it sounds like: you bring your plans to the building department counter, a plan checker reviews them while you wait (or within a few business days), and you walk out with an approved permit. Standard plan check, by contrast, involves submitting your plans and waiting weeks or months for a detailed review, potentially going through multiple rounds of revisions before receiving approval.

Not every ADU project qualifies for OTC approval, and not every city offers it. In this comprehensive guide, we will compare these two approval processes in detail, explain which cities currently offer OTC for ADUs, outline the requirements for qualifying, and help you determine which pathway is best for your specific project.

What Is Over-the-Counter ADU Approval?

Over-the-counter (OTC) approval is an expedited permitting process where building department staff review your ADU plans in real-time or within a compressed timeframe (typically 1 to 5 business days). Instead of submitting plans and waiting weeks for a plan checker to get to your project, you bring your plans to the counter and receive same-day or next-day review.

OTC programs were created to reduce the permitting backlog and make it easier for homeowners to build ADUs. They are part of California's broader effort to streamline the ADU approval process and increase housing production. However, OTC approval comes with specific requirements and limitations.

How OTC Typically Works

1. Preparation: You prepare a complete set of plans that meets specific OTC requirements (usually pre-approved plans or plans that meet specific criteria)
2. Appointment or walk-in: You either schedule an appointment or walk in to the building department counter
3. Review: A plan checker reviews your plans at the counter, checking for code compliance, setback requirements, and completeness
4. Corrections (if needed): If minor corrections are needed, you may be able to make them on the spot and resubmit
5. Approval: If your plans pass review, you pay the permit fees and receive your approved permit

Factor	Over-the-Counter	Standard Plan Check
Review timeline	1-5 business days	4-12 weeks
Revision cycles	Usually 0-1	Often 1-3
Total permit timeline	1-2 weeks	2-6 months
Design flexibility	Limited (pre-approved or simple)	Full custom design
Plan complexity	Simpler plans required	Complex plans accepted
Professional help needed	Still recommended	Essential
Cost savings	Significant (no revision fees)	Higher due to revisions

California Cities Offering OTC ADU Approval

Not all California cities offer OTC approval for ADUs. The availability and specifics vary widely. Here are some cities that have implemented OTC or express ADU permitting programs:

City of Los Angeles

Los Angeles offers an Express Plan Check program through LADBS that can expedite ADU permit review. While not a true "over-the-counter" same-day process for custom ADUs, the city has worked to reduce review times for qualifying ADU projects. The city also has a Standard Plan program that allows faster approval for ADUs built from pre-approved plan sets. Check the LADBS website for current program details and eligibility requirements.

City of San Jose

San Jose has been a leader in OTC ADU approvals, offering same-day or next-day review for ADU projects that use pre-approved plans or meet specific criteria. Their program has been cited as a model for other California cities.

City of San Diego

San Diego offers an expedited ADU permit process and has adopted a library of pre-approved ADU plans that can be permitted on an accelerated timeline. The city's Development Services Department provides specific guidance on qualifying for expedited review.

City of Sacramento

Sacramento has implemented an OTC-style program for ADUs that meet specific design parameters, including pre-approved plans and standard construction specifications. The city has been actively working to reduce ADU permitting timelines.

Other Cities

Many other California cities have implemented various forms of expedited ADU review, including Stockton, Encinitas, and several cities in the Bay Area. The trend toward faster ADU permitting is growing across the state, and new programs are being introduced regularly. Check with your specific building department for current availability.

How to Qualify for OTC ADU Approval

The requirements for OTC approval vary by city, but common criteria include:

Pre-Approved Plans

Many OTC programs require you to use a plan from a city-approved library of standard ADU designs. These plans have already been reviewed for code compliance, structural adequacy, and Title 24 energy requirements. Using a pre-approved plan eliminates the need for detailed plan review because the building department has already vetted the design. The homeowner simply needs to demonstrate that the pre-approved plan fits their specific lot (correct setbacks, proper utility connections, etc.).

Size Limitations

Some OTC programs are limited to smaller ADUs (typically 750 square feet or less) or single-story structures. Larger or more complex ADUs may be required to go through standard plan check even if the city offers OTC for simpler projects.

Construction Type

OTC programs often favor conventional wood-frame construction methods and standard foundation types. If your ADU involves unusual construction (steel frame, concrete, etc.) or complex structural systems, you may not qualify for OTC review.

Site Conditions

Properties in certain zones or conditions may be excluded from OTC review. Common exclusions include properties in hillside areas requiring grading analysis, properties in flood zones or VHFHSZ fire zones, properties with significant slope or unstable soil conditions, and properties in historic districts or specific plan areas. These properties typically require more detailed review that cannot be completed at the counter.

Complete Submittal Package

Even with OTC review, your submittal package must be complete. This includes all required plans, structural calculations, Title 24 compliance documentation, and any required supplemental reports (soils, survey, etc.). An incomplete package will be rejected at the counter, wasting your trip and your time.

Understanding Standard Plan Check

Standard plan check is the traditional permit review process used by most California building departments. Here is how it works in detail:

Intake

You submit your complete plan set to the building department. The intake staff verifies that you have provided all required documents and fees. Your plans are assigned a plan check number and routed to the review queue.

Multi-Desk Review

Your plans are reviewed by multiple departments or desks, each with their own area of expertise. In a large city like Los Angeles, your plans may be reviewed by building and safety (structural, plumbing, mechanical, electrical), fire department, planning department (zoning), bureau of engineering (grading, public works), and department of water and power (electrical service). Each desk reviews independently and generates a list of corrections.

Correction Letter

After all desks complete their review, a correction letter is compiled and sent to you (or your architect). The correction letter lists every item that needs to be addressed before approval can be granted. Some items are mandatory corrections while others may be informational notes.

Revision Submittal

You (or your architect) address all corrections, prepare revised plans, and resubmit for another round of review. The re-review typically takes 2 to 4 weeks. If all corrections are adequately addressed, your plans are approved. If not, another correction letter is issued and the cycle repeats.

Learn more about how to minimize revisions in the standard plan check process.

Which Process Should You Choose?

The choice between OTC and standard plan check depends on several factors specific to your project:

Choose OTC If:

• Your city offers OTC for ADUs and your project qualifies
• You are willing to use a pre-approved plan design
• Your lot is relatively straightforward (flat, no special zones)
• You want to minimize permitting time and get construction started quickly
• Your ADU is smaller (typically under 750 sq ft) and single-story

Choose Standard Plan Check If:

• You want a fully custom ADU design tailored to your lot
• Your property has special conditions (hillside, flood zone, historic district)
• Your ADU is larger or more complex (two-story, unusual construction)
• Your city does not offer OTC for ADU projects
• You need flexibility in design that pre-approved plans do not offer

The Rise of Pre-Approved ADU Plans

Pre-approved plan libraries are becoming increasingly popular across California. These are collections of ADU designs that have already been reviewed and approved by the building department for code compliance. When you use a pre-approved plan, the permitting process is dramatically simplified because the city has already verified that the design meets building codes, structural requirements, energy standards, and fire safety requirements.

What still needs to be reviewed (even with pre-approved plans) includes the specific site conditions (setbacks, grading, utility connections), the foundation design (which may need to be adapted to site-specific soil conditions), and any site-specific modifications to the standard plan.

Several organizations are working to create statewide libraries of pre-approved ADU plans. The California HCD has encouraged this approach as a way to reduce permitting barriers and costs. Explore our collection of ADU floor plans to see available designs.

Frequently Asked Questions

Can I switch from standard plan check to OTC if my city offers both?

Generally, no. Once your plans are submitted for standard plan check, they are in the review queue and cannot be transferred to OTC. However, you may be able to withdraw your plan check application and resubmit for OTC if your project qualifies. This may involve additional fees and a new application. Check with your building department for their specific policy.

Are OTC-approved ADUs inspected the same as plan check ADUs?

Yes. Regardless of how the permit was approved, all ADUs go through the same inspection process during construction. Inspections cover foundation, framing, plumbing, electrical, mechanical, insulation, and final occupancy. The inspection schedule and requirements are the same for OTC and plan check permits.

Does OTC approval cost less than standard plan check?

Permit fees are generally the same whether you go through OTC or standard plan check. The cost savings from OTC come from avoiding revision cycles (architect fees, structural engineer re-reviews, Title 24 updates) and reducing the overall project timeline (lower construction cost escalation, earlier rental income). These indirect savings can be substantial, often $5,000 to $15,000 or more.

Can I modify a pre-approved plan and still get OTC approval?

It depends on the city and the extent of the modifications. Minor modifications (such as moving a window or changing a material) may be acceptable within the OTC process. Significant modifications (changing the footprint, adding a story, modifying the structural system) typically disqualify the project from OTC and require standard plan check review. Always check with the building department before modifying a pre-approved plan.

What if the plan checker finds problems during OTC review?

If minor issues are identified during OTC review, you may be able to address them on the spot (redline corrections on the plans) and resubmit the same day. If significant issues are found, your plans may be rejected for OTC and routed to standard plan check. This is why it is critical to have thoroughly prepared plans even for OTC submittal. Getting everything right the first time matters in any approval process. Learn about our complete ADU cost guide for budgeting your project.

Is OTC approval available for garage conversions?

Some cities offer OTC or expedited approval specifically for garage conversion ADUs because they tend to be simpler projects (no new foundation, existing structure). However, garage conversions have their own specific requirements (fire separation from the main home, structural modifications, ventilation) that must be addressed. Check with your building department for their specific garage conversion ADU process.

Decision Flowchart: Which ADU Approval Path Is Right for You?

Choosing between over-the-counter (OTC) and plan check approval for your ADU depends on several factors. Use this decision guide to determine which process best fits your project.

Step 1: Check Your ADU Type

If you are building a Junior ADU (JADU) within your existing home or converting an existing structure like a garage, you may qualify for the faster OTC process. New detached construction typically requires plan check review.

Step 2: Verify Your City's OTC Program

Not all California cities offer an OTC approval path. Cities like Los Angeles, San Diego, and San Jose have established OTC programs for qualifying ADU projects. Contact your local planning department or visit their website to confirm whether OTC review is available in your jurisdiction.

Step 3: Review Size and Complexity

OTC programs usually have size limitations. Many cities limit OTC approval to ADUs under 750 or 800 square feet, or to projects using pre-approved plans. If your ADU exceeds the size threshold or involves custom design elements, plan check is likely required.

Step 4: Assess Site Conditions

Properties with slopes, easements, flood zones, or proximity to property line disputes may require the more thorough plan check review regardless of ADU size. If your property has any of these complexities, plan check ensures all site-specific issues are addressed before construction begins. Learn more about property boundary issues in our guide on plan check property line issues.

Step 5: Consider Your Timeline

OTC approval can be completed in as little as one to three days, while plan check typically takes four to eight weeks. If time is a priority and your project qualifies, OTC offers a significant advantage. However, rushing through OTC without proper preparation can result in issues during construction inspections.

Frequently Asked Questions

Can I switch from plan check to over-the-counter approval after submitting?

Generally, no. Once you submit your application through the plan check process, it follows that review path. However, you can withdraw your application and resubmit through OTC if your project meets the eligibility requirements. Keep in mind that any fees paid for plan check may not be refundable.

Is over-the-counter approval less thorough than plan check?

OTC review covers the same building code requirements as plan check but is designed for simpler projects that can be evaluated more quickly. Your ADU must still meet all structural, fire safety, plumbing, and electrical codes. The difference is in the complexity of the review, not the safety standards applied.

What documents do I need for over-the-counter ADU approval?

Typical OTC submissions include completed permit applications, site plans showing the ADU location on your property, floor plans with dimensions, elevation drawings, structural calculations (often simplified for smaller projects), Title 24 energy compliance forms, and proof of property ownership. Some cities also require a soils report or survey, depending on site conditions.

Will my ADU inspection process differ based on the approval path?

No. Regardless of whether your ADU was approved through OTC or plan check, the construction inspection process is the same. You will need inspections at each phase of construction, including foundation, framing, rough plumbing and electrical, insulation, and final inspection. Learn about preparing for a smooth approval in our article on winning ADU plan approval without revisions.

Do pre-approved ADU plans guarantee over-the-counter approval?

Pre-approved plans significantly increase your chances of OTC approval, but they do not guarantee it. Site-specific conditions such as setback compliance, utility connections, and zoning overlays still need to be reviewed. Pre-approved plans mainly streamline the structural and design review portions of the process, saving time on the aspects that most commonly cause delays.