San Diego County Inclusionary Housing Ordinance: Multi-Unit Developer Guide for October 22, 2026 Compliance

On October 22, 2026 — just four days from now — San Diego County's new inclusionary housing ordinance takes effect, fundamentally changing how multi-unit developers approach project feasibility in unincorporated areas. Adopted by the Board of Supervisors on June 24, 2026, this ordinance requires all housing developments with 10 or more units submitted after October 21, 2026 to include affordable housing components or pay in-lieu fees. For Pacific Beach builders planning projects in coastal unincorporated areas near Pacific Beach, La Jolla (including Tourmaline Surfing Park), Mission Beach, and Bird Rock, understanding these new requirements is critical to protecting profit margins and ensuring compliance. This comprehensive guide breaks down exactly what builders need to know about the ordinance, compliance options, financial impacts, and strategic planning considerations for multi-unit developments in San Diego County's unincorporated areas.

What is the Inclusionary Housing Ordinance?

The San Diego County Inclusionary Housing Ordinance is a new regulatory framework that requires qualifying residential developments in unincorporated areas to include or financially support deed-restricted affordable housing. Starting October 22, 2026, all housing development projects submitted to the County with ten or more units must satisfy inclusionary housing requirements by building affordable housing on-site or supporting affordable housing through alternative compliance methods.

The Board of Supervisors adopted this ordinance on June 24, 2026 in a 4-1 vote, establishing a 10-unit minimum project threshold and creating a prioritized list of alternative compliance tools including land donation with covenants, on-site affordable for-sale ADUs, and in-lieu fees. The effective date of October 22, 2026 means any project submitted after October 21, 2026 will be subject to these new requirements.

This ordinance applies exclusively to unincorporated San Diego County areas and operates separately from the City of San Diego's existing inclusionary housing regulations, which have been in effect since 2003. Builders working in both jurisdictions must understand the distinct requirements for each.

Who is Affected by the 10-Unit Threshold?

The ordinance applies to new residential projects of 10 or more units in the unincorporated areas of San Diego County. This threshold is critical because it determines which developments trigger inclusionary requirements and which remain exempt.

Key applicability factors include:

Project Size: The 10-unit minimum means developments with 9 units or fewer are exempt from inclusionary requirements. This creates a natural breakpoint in project planning where builders must decide whether to stay below the threshold or plan for compliance costs.

Geographic Coverage: The ordinance applies only to unincorporated San Diego County areas, not incorporated cities. While Pacific Beach, La Jolla, Mission Beach, and Bird Rock are within the City of San Diego jurisdiction and therefore subject to the city's separate inclusionary ordinance (which has a 10-unit threshold outside coastal zones and 5-unit threshold in coastal overlay zones), developers working in nearby unincorporated coastal areas such as Del Mar Heights (adjacent to La Jolla and Tourmaline Surfing Park) and University City areas must comply with the County ordinance.

Exemptions: Small-scale developments, single-family homes, and lot splits that fall below the 10-unit threshold are exempt. Additionally, projects submitted before October 22, 2026 are grandfathered under previous regulations without inclusionary requirements. Developers considering ADU projects should note that stand-alone ADUs typically don't trigger this threshold.

Submittal Timing: The critical deadline is October 21, 2026. Projects with complete applications submitted by this date avoid the new requirements. Projects submitted on October 22, 2026 or later must fully comply with inclusionary housing and in-lieu fee ordinance requirements.

Compliance Options: On-Site Units vs. In-Lieu Fees

The County ordinance establishes a prioritized hierarchy of compliance options, requiring developers to pursue alternatives in a specific order:

1. Land Donation (Highest Priority): Developers may donate land to the County for future affordable housing development instead of constructing required set-aside units. This option is available within incorporated areas, village areas, VMT-efficient or infill areas, or high/highest resource areas as defined in the General Plan. Land donations provide a compliance pathway without directly reducing market-rate unit count.

2. Affordable For-Sale ADUs: Developers may build affordable accessory dwelling units on-site as part of compliance. This option allows integration of smaller affordable units within the project while maintaining primary market-rate units.

3. In-Lieu Fees (Partial Compliance): In-lieu fees can cover up to half of the affordable housing obligation and may be combined with other compliance measures. The County's in-lieu fee structure is designed to represent the affordability gap — the difference between market-rate and affordable unit revenue. While specific County fee rates are still being finalized, the City of San Diego's fiscal year 2026-27 in-lieu rate of $25.92 per square foot provides a benchmark for expected costs.

4. Off-Site Development (Last Resort): Building affordable units at another location is permitted but ranks lowest in the compliance hierarchy.

This prioritized structure means developers cannot simply choose the most convenient option — they must demonstrate why higher-priority alternatives are infeasible before pursuing lower-ranked options. This framework significantly impacts project planning and financial modeling.

Financial Impact on Project Feasibility

The inclusionary housing ordinance fundamentally alters project economics for 10+ unit developments. Builders must integrate compliance costs into feasibility analysis from the earliest planning stages.

Cost Per Affordable Unit: Affordable housing development in San Diego County costs an average of $574,000 per unit based on recent San Diego Housing Commission data, with some projects exceeding $900,000 per unit. This represents the cost gap developers must absorb when providing on-site affordable units.

Percentage Requirements: While the County ordinance sets tiered set-asides, typical inclusionary requirements range from 5-20% of total units. Using the City of San Diego's 10% standard as a benchmark, a 20-unit project would need to provide 2 affordable units or equivalent compliance value.

In-Lieu Fee Calculations: For a hypothetical 12-unit project in unincorporated County areas near coastal communities, assuming 1,200 square feet per unit and a $26 per square foot in-lieu fee (based on City rates), the total fee burden would be approximately $374,400 ($26 × 1,200 sq ft × 12 units). However, if in-lieu fees can only cover 50% of the obligation, additional compliance through land donation or affordable ADUs would be required.

Profit Margin Impact: For market-rate units selling at $800,000 to $1.2 million in coastal areas, affordable unit requirements priced at 60% AMI ($68,900 for a family of four) create substantial revenue gaps. This affordability gap directly reduces developer returns and may render marginal projects infeasible.

Strategic Threshold Management: Some developers may strategically limit projects to 9 units to avoid triggering inclusionary requirements, though this approach sacrifices economies of scale and land utilization efficiency.

In-Lieu Fee Structure and Calculation Methodology

In-lieu fees represent a critical compliance option for developers who prefer financial contributions over on-site affordable unit construction. Understanding the calculation methodology is essential for accurate project budgeting.

Fee Basis: In-lieu fees are calculated to represent the cost developers would incur providing required affordable units on-site. This is the affordability gap — the difference in sales price (for-sale projects) or rental revenue (rental projects) between affordable units and equivalent market-rate units.

Calculation Method: The in-lieu fee for each development equals the applicable per-square-foot charge multiplied by the net building area. For the City of San Diego, the fiscal year 2026-27 rate is $25.92 per square foot applied to total market-rate square footage.

County Rate Expectations: While San Diego County's specific in-lieu fee schedule is still being finalized, the Board directed staff to return with an updated feasibility study in fiscal year 2027-28. Developers should anticipate rates comparable to or potentially lower than City rates given the County's focus on ensuring project viability.

Partial Compliance Limitation: A critical constraint is that in-lieu fees can satisfy only up to 50% of the affordable housing obligation under the County ordinance. This means developers must combine fee payments with other compliance methods like land donation or affordable ADUs to meet full requirements.

Payment Timing: In-lieu fees are typically due at building permit issuance, creating a significant upfront capital requirement that must be factored into construction financing and cash flow projections.

Strategic Planning for Coastal Multi-Unit Projects

Developers planning multi-unit projects in unincorporated coastal areas near Pacific Beach's Tourmaline Surfing Park, La Jolla's coastal bluffs, Mission Beach, and Bird Rock face unique strategic considerations. Each area presents distinct challenges: Tourmaline-area projects must balance coastal access preservation with density requirements, while La Jolla bluff developments face stringent setback requirements.

Jurisdictional Analysis: First, confirm whether your project site is within City of San Diego boundaries (subject to City inclusionary ordinance) or unincorporated County territory (subject to County ordinance). Pacific Beach, La Jolla, Mission Beach, and Bird Rock are within City limits, but nearby unincorporated coastal areas exist.

Pre-Application Timing: Projects in advanced planning stages should evaluate whether complete applications can be submitted by October 21, 2026 to grandfather under previous regulations. However, rushing submissions may compromise project quality and create permitting delays.

Compliance Strategy Selection: Evaluate the prioritized compliance options based on project-specific constraints:

• Land Donation: Most viable for developers with multiple parcels or access to suitable affordable housing sites
• Affordable ADUs: Works well for larger lot developments where accessory units integrate naturally
• In-Lieu Fees + Secondary Compliance: Suitable for projects with strong market-rate margins able to absorb fee costs

Financial Modeling Scenarios: Run feasibility analysis under multiple compliance scenarios to identify the least costly approach. Include sensitivity testing for fee rate variations and affordable unit percentage requirements.

Partnership Opportunities: Consider partnering with affordable housing developers or nonprofits to handle affordable unit components, allowing the market-rate developer to focus on core competencies.

Density Bonus Integration: The County ordinance includes expanded density bonus incentives. Evaluate whether additional market-rate units enabled through density bonus can offset affordable unit costs. Understanding multi-unit development strategies across the region can help optimize compliance approaches.

Coastal Overlay Zone Considerations

Multi-unit developments in coastal areas face combined requirements from both inclusionary housing ordinance and coastal development permitting processes.

Dual Regulatory Framework: Projects in the Coastal Overlay Zone must secure both inclusionary housing compliance and Coastal Development Permits (CDP). For City of San Diego projects, the inclusionary threshold drops to 5 units in coastal zones (versus 10 units elsewhere).

AB 462 Concurrent Review: AB 462 requires 60-day concurrent Coastal Development Permit review for qualifying projects. This streamlined timeline applies to ADU permits and other coastal zone developments, potentially reducing approval timelines.

Height Limitations: Coastal communities including Pacific Beach, La Jolla, and Mission Beach face 30-foot coastal height limits, creating particular challenges when density bonus projects attempt to exceed these restrictions. Developers must carefully evaluate how affordable unit requirements interact with height constraints.

Local Coastal Features: Projects near Tourmaline Surfing Park in Pacific Beach must consider public coastal access requirements and recreational area buffers. Developments adjacent to Crystal Pier or the Pacific Beach boardwalk face additional design review scrutiny to maintain coastal character. La Jolla Shores area projects encounter bluff erosion considerations, while Bird Rock developments must integrate with the established low-rise coastal community character.

Coastal Bluff Setbacks: Projects near coastal bluffs face additional setback requirements. As of July 1, 2026, San Diego implemented updated coastal bluff setback guidance incorporating refined erosion modeling for Pacific Beach, La Jolla, and Bird Rock. These setbacks may limit buildable area and affect unit count calculations.

California Coastal Commission Authority: The April 2026 California Supreme Court ruling affirmed Coastal Commission authority over coastal development. Developers must ensure inclusionary housing compliance strategies align with coastal permitting requirements to avoid regulatory conflicts.

Partnership Opportunities with Affordable Housing Specialists

The inclusionary housing ordinance creates significant partnership opportunities for developers willing to collaborate with affordable housing experts.

Affordable Housing Developer Partnerships: Market-rate developers can partner with affordable housing specialists to design, build, and manage required affordable units. This approach leverages specialized expertise in financing affordable housing through Low-Income Housing Tax Credits (LIHTC), HUD programs, and County resources.

Nonprofit Collaborations: Nonprofit affordable housing developers like San Diego Housing Commission partners can take ownership of affordable unit components, often accessing funding sources unavailable to for-profit developers.

Land Banking Arrangements: Developers with excess land holdings can donate parcels to affordable housing organizations, satisfying compliance requirements while creating community benefit.

ADU Specialization: Builders with ADU construction expertise can offer affordable ADU development services to larger developers seeking on-site compliance options.

Consulting Services: Understanding complex inclusionary requirements creates demand for specialized consulting helping developers navigate compliance options, calculate costs, and optimize strategies.

Long-Term Management: Affordable units require 55-year affordability periods for rental units and 45-year periods for ownership. Partnering with experienced affordable housing managers ensures long-term compliance and reduces developer operational burden.

Timeline and Submittal Requirements

Understanding critical deadlines and submittal requirements is essential for developers navigating the transition to the new ordinance.

October 21, 2026 Deadline: Projects submitted with complete applications by October 21, 2026 are grandfathered under previous regulations without inclusionary requirements. This creates a 4-day window (from October 18) for projects in final planning stages.

October 22, 2026 Effective Date: All projects submitted on or after October 22, 2026 must fully comply with inclusionary housing and in-lieu fee ordinance requirements. No exceptions or phase-ins apply after this date.

Application Completeness Standards: To qualify for grandfathering, applications must meet County completeness standards. Incomplete or deficient applications will be returned and resubmitted applications fall under the new ordinance if resubmission occurs after October 21.

Compliance Approval Process: Developers must demonstrate compliance with inclusionary requirements during project review. The County will review proposed compliance strategies and approve methods consistent with the prioritized hierarchy.

Affordability Period Enforcement: Deed restrictions for affordable units remain in effect for 55 years (rental) or 45 years (ownership) from project completion. The County conducts periodic inspections to verify ongoing compliance.

Future Feasibility Study: The Board directed staff to return with an updated feasibility study in fiscal year 2027-28, which may result in ordinance modifications. However, projects submitted after October 21, 2026 will be subject to current requirements unless retroactive relief is provided.

Comparison: County vs. City of San Diego Requirements

Developers working across jurisdictions must understand critical differences between San Diego County and City of San Diego inclusionary ordinances.

Implementation Timeline: The City of San Diego's inclusionary ordinance has been effective since 2003, while the County ordinance takes effect October 22, 2026. The City's ordinance is mature with established fee schedules and compliance procedures, while County implementation details are still evolving.

Project Thresholds: Both jurisdictions use a 10-unit threshold for standard projects. However, the City reduces the threshold to 5 units in Coastal Overlay Zones, while the County maintains 10 units across all unincorporated areas.

Affordability Percentage: The City requires 10% of total units for both rental (60% AMI) and ownership (120% AMI) projects. The County's specific percentages remain under finalization but modeled scenarios examined 5-20% set-asides, suggesting potential variation by project type.

Affordability Periods: The City requires 55-year affordability for rental units and 45 years for ownership. The County ordinance includes similar long-term restrictions.

In-Lieu Fee Rates: The City's fiscal year 2026-27 rate is $25.92 per square foot. County rates are pending but will be calibrated to represent local affordability gaps.

Alternative Compliance: The County's prioritized hierarchy (land donation, affordable ADUs, partial in-lieu fees, off-site development) differs from the City's more flexible menu approach. This ranking system limits developer choice in County projects.

Geographic Scope: Understanding jurisdictional boundaries is critical. Pacific Beach, La Jolla, Mission Beach, and Bird Rock are within City limits and subject to City ordinance. Nearby unincorporated coastal areas fall under County ordinance.

Case Study: 12-Unit Project Compliance Analysis

To illustrate real-world compliance requirements, consider a hypothetical 12-unit residential development in the Del Mar Heights unincorporated area adjacent to La Jolla and Tourmaline Surfing Park.

Project Parameters:

• 12 market-rate residential units
• 1,200 square feet average per unit
• Total project square footage: 14,400 sq ft
• Estimated market-rate sale price: $950,000 per unit
• Total market-rate revenue: $11.4 million

Compliance Scenario 1: On-Site Affordable Units (10% Set-Aside)

• Required affordable units: 1.2 units (rounded to 2 units at 60% AMI)
• Affordable unit sale price: ~$400,000 (affordable to 60% AMI household)
• Revenue reduction: 2 units × ($950,000 - $400,000) = $1.1 million
• Effective compliance cost: $1,100,000

Compliance Scenario 2: In-Lieu Fees + Land Donation

• In-lieu fee (50% compliance): $25.92 × 14,400 sq ft × 50% = $186,624
• Land donation value (50% compliance): ~$500,000 (approximate)
• Total compliance cost: $686,624

Compliance Scenario 3: Affordable ADUs

• Build 2 affordable ADUs at 800 sq ft each
• ADU construction cost: ~$300,000 per unit = $600,000
• ADU sale price: ~$300,000 per unit (affordable)
• Net compliance cost: $600,000 construction cost (no revenue offset if donated)

Optimal Strategy: For this scenario, the combination of in-lieu fees plus land donation (Scenario 2) offers the lowest compliance cost at $686,624, preserving more project revenue than on-site affordable units while maintaining full market-rate unit count.

Profit Impact: With total revenue of $11.4 million and typical development margins of 15-20%, the compliance cost of $686,624 represents 6% of gross revenue and approximately 30-40% of expected profit, significantly impacting project returns.

Frequently Asked Questions