AB 507 Office-to-Housing Conversions in San Diego: Downtown Opportunities (2026)

What is AB 507 and How Does It Work?

AB 507, California's Office to Housing Conversion Act, establishes a ministerial, CEQA-exempt approval process for converting existing nonresidential buildings—including office, industrial, commercial buildings, and hotels—into residential housing or mixed-use developments. The legislation allows for the adaptive reuse of buildings as residential and mixed-use projects, provided that developments meet specific affordable housing, historic preservation, and prevailing wage and labor standards.

Ministerial Approval Timeline:

Under AB 507, local agencies must approve qualifying projects within strict deadlines:

• 60 days for developments with 150 units or fewer
• 90 days for projects with more than 150 units

This represents a dramatic acceleration compared to traditional discretionary review processes that historically delayed adaptive reuse projects by 12-24 months. The San Diego Planning Department now processes these ministerial approvals without the lengthy public hearings, environmental review processes, and discretionary decision-making that characterized previous conversion attempts.

Affordability Requirements:

AB 507 qualifies projects with the following affordability options for rental projects:

1. 8% very low-income and 5% extremely low-income units, OR
2. 15% low-income units, OR
3. For owner-occupied housing: 30% moderate-income or 15% low-income units

Labor Standards:

The law imposes prevailing wage, apprenticeship, skilled and trained workforce, and healthcare expenditure requirements, depending on the size and other characteristics of the project. These standards ensure quality construction while supporting California's construction workforce.

Local Incentives:

To further incentivize adaptive reuse projects, AB 507 authorizes local jurisdictions to establish adaptive reuse investment incentive programs to generate funds for conversion projects. San Diego has been exploring various financial mechanisms to support qualifying developments, particularly those targeting affordable housing production.

Downtown San Diego's Office Vacancy Crisis

Downtown San Diego faces the most severe commercial real estate challenges in over 30 years, with office availability approaching 36% in 2026—more than double the metro-wide average of 15.0%. This crisis is particularly concentrated in East Village and along the Broadway corridor, where approximately 11 downtown high-rise office buildings currently face foreclosure or forced sale.

Submarket Vacancy Breakdown:

According to Kidder Mathews research, downtown recorded the highest submarket vacancy at 33.1% in Q3 2026, though more recent data shows availability approaching 36% when accounting for shadow space and buildings in distress. The concentration in specific neighborhoods creates targeted opportunities:

• East Village: Multiple high-rise office towers with availability exceeding 40%
• Broadway Corridor: Historic office buildings with legacy tenants relocating to suburban markets
• Little Italy: Mixed-use office properties adjacent to residential neighborhoods
• Harbor Drive: Waterfront office buildings impacted by remote work trends

Market Value Reset:

Downtown San Diego office buildings have sold at an average of $206-$215 per square foot in 2026, well below the $300-$400 per square foot valuations from 2018-2019. This represents a 40-50% discount from peak values, creating what cash buyers view as a generational buying opportunity. A wave of high-rise trades is resetting downtown ownership and values, driven largely by major portfolio sales at steep discounts.

Notable Distressed Transactions:

• 707 Broadway: 18-story tower sold for $21 million ($105 per square foot) in December 2025
• One & Two Columbia Place: Sold for $104 million in downtown core
• High Bluff Ridge: Del Mar Heights/Carmel Valley property sold for $95,475,000 ($578.84 per square foot)

The disparity between downtown pricing ($206-$215/sf) and suburban pricing ($578/sf for High Bluff Ridge) illustrates the severity of the downtown crisis and the corresponding opportunities for conversion projects.

Housing Production Gap:

While office space sits vacant, San Diego requires 76,399 new homes by 2029, with an annual production requirement of 15,280 homes. The city continues to fall behind on these housing production goals, making office-to-housing conversions an increasingly critical solution. The San Diego Housing Commission has already begun exploring strategies to take over vacant or struggling office buildings and convert them into homes for low-income or formerly unhoused residents.

Ministerial Approval: Dramatic Timeline Advantages

The ministerial approval process under AB 507 eliminates the single largest barrier to office conversions: time. Traditional rezoning and discretionary approval processes for adaptive reuse projects historically required 12-24 months before construction could even begin. AB 507's streamlined approach compresses this timeline to 60-90 days, fundamentally changing project economics.

Timeline Comparison Table:

Economic Impact:

The timeline compression creates substantial economic advantages:

1. Carrying Cost Savings: Reducing holding period by 10-22 months eliminates significant carrying costs including property taxes, insurance, security, and debt service on vacant buildings
2. Revenue Acceleration: Getting residential units to market 12-18 months faster allows developers to capture rental income or sales proceeds substantially earlier
3. Market Risk Reduction: Shorter approval timelines reduce exposure to changing market conditions, interest rate fluctuations, and construction cost escalation
4. Capital Efficiency: Faster project completion allows investors to recycle capital into additional projects rather than tying up funds in extended approval processes

For office conversions requiring 18-30 months from acquisition to certificate of occupancy—compared to 36-48 months for ground-up residential construction—the AB 507 ministerial process provides a critical advantage in bringing housing units to market quickly.

Recent Conversion Projects: October 2026 Update

San Diego has seen significant momentum in office-to-housing conversions throughout 2026, with two major downtown projects advancing through different stages of development.

101 Ash Street (Now 107 Ash Street):

In September 2026, the San Diego City Council voted to amend the city's deal to convert the troubled 101 Ash office tower into affordable housing for low-income renters. The council had approved the general concept for the housing conversion in 2025, and the September 2026 vote tweaked details of the deal now that financing mechanisms and building plans were finalized. For more details on this landmark project, see our complete analysis of the 101 Ash Street conversion.

Project Specifications:

• Building: 21-story high-rise (originally opened 1968)
• Housing Units: 252 affordable apartments (increased from initial 250)
• Commercial Space: 25,000 square feet
• Childcare Center: 4,000 square feet
• Project Cost: $254.7 million
• Funding Sources: 8 sources including HUD and San Diego Foundation
• Ground Lease: 65 years (extended from 60)
• Interest Rate to City: 5% compound interest (increased from 4% simple)

The 101 Ash Street project represents a particularly compelling case study because the building has sat vacant since 2020 after asbestos was discovered following a $32 million remodel. Taxpayers have paid $5 million annually for upkeep of the vacant tower, making the conversion both a financial and social imperative.

707 Broadway:

Vintage Housing purchased the 18-story skyscraper at 707 Broadway for $21 million in December 2025, planning to convert the building into 200 residential units targeting low- and very-low-income families.

Project Specifications:

• Building: 19-story office tower (18-story according to some sources)
• Purchase Price: $21 million (approximately $105 per square foot)
• Housing Units: 200 fully affordable apartments
• Unit Mix: 142 one-bedroom units, 58 two-bedroom units
• Target Population: Low- and very-low-income families
• Construction Start: March 2025
• Expected Occupancy: Late 2026 or early 2027
• Timeline: 18-30 month transformation

Both projects demonstrate the viability of office-to-housing conversions in San Diego's downtown core, particularly for buildings that have struggled to maintain office tenancy in the post-pandemic environment. The $21 million acquisition price for 707 Broadway—in a building that would cost substantially more to build from the ground up—illustrates the value proposition available to cash buyers targeting distressed office properties.

Impact on Property Values and Market Dynamics

The convergence of high office vacancy, AB 507's streamlined approval process, and distressed property pricing has created a complex impact on San Diego commercial real estate values, particularly in downtown neighborhoods.

Valuation Compression:

Downtown San Diego office buildings trading at $206-$215 per square foot in 2026 represent a fundamental repricing of urban office assets. This 40-50% discount from 2018-2019 peak values reflects:

1. Sustained Vacancy: Office vacancy approaching 36% downtown eliminates pricing power for landlords
2. Remote Work Permanence: Recognition that pre-pandemic office demand patterns will not fully return
3. Conversion Potential: Market pricing now reflects highest and best use as residential rather than office
4. Distressed Ownership: Wave of foreclosures and forced sales by overleveraged owners

Cash Buyer Competitive Advantages:

Cash buyers possess several critical advantages in the current market environment:

1. Speed: All-cash offers close in 14-30 days versus 60-90 days for financed transactions
2. Certainty: No financing contingencies eliminate deal risk for distressed sellers
3. As-Is Purchases: Cash buyers acquire buildings in current condition without requesting repairs or credits
4. Bulk Opportunities: Ability to acquire multiple buildings or entire portfolios
5. Bridge Financing: Cash acquisition allows time to secure construction financing for conversion

Property owners facing foreclosure, partnership disputes, or legacy tenant departures frequently prioritize transaction certainty and speed over maximum price, creating opportunities for well-capitalized cash buyers to acquire conversion candidates at favorable pricing. If you're considering selling your commercial property, contact us for a no-obligation consultation to explore your options.

Opportunities for Cash Buyers: Strategic Acquisition Approach

Cash buyers targeting San Diego office-to-housing conversion opportunities should adopt a systematic approach to identify, evaluate, and acquire properties positioned for adaptive reuse.

Target Property Characteristics:

Ideal Building Profile:

• Location: Downtown, East Village, Little Italy, or Mission Valley near transit
• Vacancy: 50%+ vacancy or single-tenant buildings with expiring leases
• Floor Plate: 10,000-20,000 square feet (supports efficient unit layouts)
• Window Spacing: 15-25 feet on center (aligns with residential unit widths)
• Ceiling Height: 9+ feet floor-to-floor (accommodates residential requirements)
• Building Systems: Functional life safety, HVAC, electrical, and plumbing infrastructure
• Parking Ratio: Existing parking supports residential requirements (1-1.5 spaces per unit)

Financial Underwriting Considerations:

Acquisition Economics:

• Target acquisition at $150-$250 per square foot (well below replacement cost)
• Conversion costs typically $150-$250 per square foot depending on building condition
• Total project cost $300-$500 per square foot versus $500-$700 for new construction
• AB 507 ministerial approval saves $50,000-$150,000 in soft costs and 12-24 months in timeline

Cash Buyer Process:

1. Market Intelligence: Monitor foreclosure listings, broker relationships, and distressed owner situations
2. Quick Evaluation: Conduct rapid feasibility analysis using AB 507 criteria and conversion economics
3. All-Cash Offer: Submit competitive offers with 7-14 day due diligence and 30-day close
4. Streamlined Due Diligence: Focus on building systems, code compliance, and conversion feasibility
5. AB 507 Application: Immediately initiate ministerial approval process upon acquisition
6. Construction Financing: Secure construction loan or joint venture equity for conversion
7. Fast Execution: Complete conversion in 18-24 months from acquisition to stabilized occupancy

Timeline and Process: From Acquisition to Occupancy

Understanding the complete timeline from property acquisition through residential occupancy helps cash buyers develop realistic project schedules and financial projections.

Phase 1: Acquisition (Months 0-2)

• Property identification and preliminary evaluation (Weeks 1-2)
• Cash offer submission and negotiation (Weeks 3-4)
• Due diligence period: building inspection, title review, code compliance (Weeks 5-6)
• Closing and acquisition (Week 7-8)

Phase 2: AB 507 Ministerial Approval (Months 2-4)

• Application preparation: architectural concepts, affordability plan, labor compliance (Weeks 9-12)
• Application submission to San Diego Planning Department (Week 13)
• Staff review and compliance verification (Weeks 14-17)
• Ministerial approval granted (60-90 days from complete application) (Week 18)
• Limited appeal period (Weeks 19-20)

Phase 3: Construction Financing and Permitting (Months 4-8)

• Construction drawings and specifications (Weeks 21-28)
• Construction financing or JV equity raising (Weeks 21-28)
• Building permit application (Week 29)
• Permit review and approval (Weeks 30-34)
• Final financing close (Week 34-36)

Phase 4: Construction and Conversion (Months 8-24)

• Demolition and abatement (Months 9-11)
• Core and shell renovation: MEP, life safety, envelope (Months 11-18)
• Unit build-out and finishes (Months 18-22)
• Final inspections and certificate of occupancy (Months 23-24)

Phase 5: Lease-Up and Stabilization (Months 24-30)

• Marketing and pre-leasing (Months 22-24)
• Initial occupancy and move-ins (Months 24-26)
• Stabilized occupancy achieved (90%+) (Months 28-30)

Total Timeline: 24-30 Months from acquisition to stabilized occupancy, compared to 36-48 months for ground-up development.

The AB 507 ministerial approval process eliminates 12-24 months from traditional timelines, making the difference between feasible and infeasible project economics for many conversion candidates. Cash buyers who move quickly to acquire distressed office properties in late 2026 can potentially deliver residential units to market by 2028-2029, positioning to capture strong rental demand as downtown San Diego continues its transformation.

Frequently Asked Questions

Conclusion: AB 507 Creates Historic Opportunity for Downtown San Diego

AB 507's ministerial approval process, combined with downtown San Diego's 36% office vacancy and 40-50% valuation discounts, creates what many view as a once-in-a-generation opportunity for adaptive reuse. The elimination of 12-24 month approval timelines transforms projects from economically infeasible to compelling investment opportunities.

For commercial property owners struggling with vacant office buildings, high carrying costs, and uncertain market recovery, AB 507 provides both a viable repositioning strategy and enhanced exit liquidity. Cash buyers specifically targeting conversion opportunities now represent a growing segment of the acquisition market, offering distressed owners certainty, speed, and relief from ongoing obligations.

The success of projects like 101 Ash Street ($254.7 million conversion to 252 affordable units) and 707 Broadway ($21 million acquisition for 200-unit conversion) demonstrates that downtown San Diego's office-to-housing transformation is not theoretical—it's actively underway. As approximately 11 downtown high-rise office buildings face foreclosure or forced sale, the pipeline of conversion opportunities continues expanding.

Whether you own a distressed office property, represent institutional investors seeking adaptive reuse opportunities, or provide capital for conversion projects, understanding AB 507's mechanics and San Diego's specific market dynamics is critical to capitalizing on this historic shift in downtown real estate.