Free SF apartment background check

509 Potrero Ave

Potrero Hill, SF 94110 4013023 3 units · 2 fl · 1911

This building has a higher-than-average number of open problems nearby. Few open issues; problems get fixed quickly. A reasonable bet for a smooth tenancy.

NOVs (7y) vs. neighborhood
Compared to a typical building in Potrero Hill
At or below average
avg 1.1
0
FewerMore

This building has 0 novs (7y), at or below the Potrero Hill average of 1.1.

Rent & eviction protection

Is 509 Potrero Ave rent-controlled?

San Francisco's Rent Ordinance caps rent increases and provides eviction protection for most residential units built before 1979 with 2+ units. Here's how this building scores.

Built before 1979
Built 1911
2 or more units
3 units
Property type
Multi-Family Residential
Zoning
RH2
Likely rent-controlled. Building age and unit count suggest this property falls under San Francisco's Rent Ordinance.

Based on SF Assessor records. Not legal advice — confirm with the SF Rent Board.

Building characteristics
Units3
Floors2
Year built1911
Total area4,963 sq ft
Property typeMulti-Family Residential
Tax statusNone
Blocklot4013023
Ownership

Registered owner per SF Assessor-Recorder (secured roll).

Owner name
Mark R Sidmore Living Trust
Mailing address
Mark R Sidmore Trustee 509 Potrero Ave San Francisco CA 94110
Last sale
042715

Landlord portfolio

Other SF properties this owner holds, with risk grades for each.

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Multiple entrances & addresses

Included addresses

All street addresses sharing this blocklot that are covered by this report.

509 Potrero Ave, San Francisco, CA 94110
509 B Potrero Ave, San Francisco, CA 94110
509 A Potrero Ave, San Francisco, CA 94110
Augrented Insights
Initial analysis

The property at 509 Potrero Avenue is a two-story, three-unit multi-family residential building constructed in 1911, currently owned by the Mark R Sidmore Living Trust. The building has undergone several significant renovations over the past decade, most notably a comprehensive interior remodel in 2013 of the rear cottage that included new stairs, foundation work, and bathroom additions costing $108,000. A major electrical and plumbing upgrade was performed in 2010-2013, including complete rewiring and plumbing replacement in all units, installation of new electrical panels, and updates to bathroom and kitchen facilities, with a total estimated cost exceeding $100,000.

The property experienced a notable fire incident in 2009 that affected the top floor and garage, requiring extensive repairs and system replacements throughout the building. More recently, there have been recurring sewage issues, with multiple sewer backup incidents reported between 2020 and 2023, indicating potential ongoing plumbing system challenges. Most recent plumbing work includes a house trap replacement completed in September 2024. The building has also had several street space permits issued between 2009 and 2016, and there have been various 311 calls related to the property, primarily concerning general cleaning and garbage issues. While some exterior improvements were made in 2012, including stairway and deck replacements, these were initially performed without proper permits, though they were subsequently legalized through the permitting process. The property has maintained active compliance with required inspections and permits since the fire incident, though the recurring sewer issues suggest ongoing infrastructure maintenance needs.

AI-generated · may contain errors · check the source data tables below

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Risk rating

How 509 Potrero Ave's risk score is calculated

We trained a model on 7 years of SF DBI inspection data — notice of violation filings, complaint history, and owner track records. It estimates the probability that DBI inspectors will issue a Notice of Violation at this address in the next 12 months. Lower % = safer.

What the score means for you

Grade A–B — Low risk

DBI rarely finds violations here. Strong maintenance history and a clean complaint record.

Grade C — Moderate risk

Some past violations or complaints on record. Worth asking the landlord about any open issues before signing.

Grade D–F — High risk

Elevated violation and complaint history. DBI has found issues here before and is statistically likely to again.

Neighborhood percentile
52th percentile

Out of 726 buildings in this neighborhood, 348 are predicted to be safer.

RiskiestSafest
Predicted 12-month outcome
76%
No DBI
violation
24%
DBI violation
likely
Model explanation

What's driving this score

The three data points that most influenced this building's risk rating — ranked by the weight the model placed on each one.

Neighborhood (ZIP code)

The ZIP code captures local housing market and enforcement patterns that affect all buildings in the area.

Owner's portfolio size

Number of SF parcels this owner is registered on — larger portfolios have distinct risk patterns.

Construction spend, owner's portfolio

Estimated permit value across all of this owner's buildings.

12-Month severity forecast
No violation 58.9%
Moderate concern 30.5%
Severe concern 10.7%
Estimated probability of receiving a DBI Notice of Violation in the next 12 months at each severity level. Model: full_hgb_balanced.
Apartment reviews

509 Potrero Ave apartment reviews

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The story over time

509 Potrero Ave event timeline

Violations, complaints, fire incidents, permits, and buyouts — most recent records in order.

2024
Plumbing Permit Sep 16
Work category: 1p; house trap replacement
Complete

See all 2 events

Full history back to 2023 — violations, complaints, permits, buyouts, and fire incidents.

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Every record we have

Full data for 509 Potrero Ave apartments

13 SF public datasets for this parcel — permits, violations, complaints, fire records, 311 calls, planning records, and buyouts.

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Cancel anytime · Data sourced from SF Open Data, DBI, SFFD, SF Rent Board & Planning

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