San Francisco's Permit Portal Duplicate-Image Problem: How the City Stacks Up Against London and Seoul

San Francisco's Department of Building Inspection confirmed this spring that its online permit portal, PermitSF, has been accumulating duplicate property images since a 2023 database migration, with redundant files now accounting for roughly 34 percent of the system's total storage load. The problem is not cosmetic. When inspectors in the Tenderloin and Bayview-Hunters Point pull up a permit application, they can scroll through eight or twelve near-identical photographs of the same stairwell, slowing reviews that are already under pressure from the city's housing production emergency.

The timing is lousy. Mayor Daniel Lurie's administration inherited a backlog of more than 6,000 housing permits that advocates say has contributed to stalled construction along the Van Ness Avenue corridor and in the Mission. Every efficiency loss inside PermitSF compounds that backlog. The duplicate-image issue sits at the intersection of two forces reshaping city government right now: an AI-driven tech boom that has flooded the Planning Department with complex commercial renovation applications, and a chronic shortage of senior IT staff willing to work on legacy municipal systems when private employers on Market Street are offering two or three times the salary.

What Other Cities Have Done

London's Planning Portal, which serves 33 boroughs, tackled a similar problem in 2024 after a cloud migration left duplicate images scattered across roughly 180,000 active applications. The Greater London Authority contracted with a specialist records-management firm and deployed an automated hash-matching tool that identified and flagged redundant files without deleting originals until a human reviewer signed off. The process took about seven months and, by the GLA's own public accounting, reduced portal storage costs by 22 percent.

Seoul took a different approach through its e-AIS permitting platform, integrating duplicate detection directly into the upload interface so that redundant images are flagged at the point of submission rather than discovered after the fact. The city embedded the feature into a broader 2024 digital-government overhaul and now uses the tool across 25 municipal agencies. San Francisco has studied the Seoul model, according to planning documents published on the city's open-data portal in March 2026, but has not yet issued a contract for comparable work.

San Francisco's Department of Technology has proposed using an open-source perceptual hashing library to automate duplicate detection inside PermitSF, a technically similar approach to London's solution. A request for proposals was circulated in February 2026 with a response deadline of April 11. As of the last public update posted to the city's procurement site, the evaluation period is ongoing. No award has been announced.

The Local Cost of Delay

Storage is the visible expense, but staff time is the deeper drain. The San Francisco Planning Department employed 312 full-time equivalent positions as of its fiscal year 2025–26 budget submission. Even if duplicate images cost each planner an average of fifteen minutes per complex application review, the cumulative hours across the department's caseload add up fast — particularly for large projects near Caltrain's Fourth and King Street station, where several transit-oriented development proposals are moving through simultaneous environmental and building review.

The San Francisco Housing Action Coalition, an advocacy group that tracks permit velocity, has flagged administrative inefficiency as a measurable drag on the city's goal of permitting 82,000 new units by 2031 — a state-mandated target under the Regional Housing Needs Allocation cycle. The duplicate-image backlog is one of several IT issues the coalition has cited in public comments to the Planning Commission this year.

For property owners or contractors filing applications right now, the practical advice from the Planning Department's own published guidance is straightforward: limit photo uploads to five images per inspection point, use JPEG format rather than HEIC or RAW, and label files with the permit number before uploading. That reduces — though does not eliminate — the chance of duplicate entries slipping through the current system. Larger developers working on projects in SoMa or the Dogpatch should coordinate directly with their assigned planner before submitting image-heavy packages. The city says the procurement process will be complete by the end of summer, though the contract award and subsequent implementation timeline remain unconfirmed.