Free SF apartment background check

643-645 Oak St

Hayes Valley, SF 94117 0842026 9 units · 3 fl · 1900

This building has significantly more problems than most nearby buildings. A handful of unresolved issues. Worth a careful walk-through and pointed questions.

NOVs (7y) vs. neighborhood
Compared to a typical building in Hayes Valley
Above average
avg 2.3
12
FewerMore

This building has 12 novs (7y), above the Hayes Valley average of 2.3.

Rent & eviction protection

Is 643-645 Oak St 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 1900
2 or more units
9 units
Property type
Multi-Family Residential
Zoning
RM1
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
Units9
Floors3
Year built1900
Total area6,750 sq ft
Property typeMulti-Family Residential
Tax statusNone
Blocklot0842026
Ownership

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

Owner name
Leon V & Estelita G Ribay L
Mailing address
Leon V & Estelita G Ribay, 626 Farallon Ave Pacifica CA 94044
Last sale
000000

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.

645 Oak St, San Francisco, CA 94117
643 Oak St, San Francisco, CA 94117
Augrented Insights
Initial analysis

The 9-unit, 3-story multi-family residential building at 643-645 Oak Street in Hayes Valley, owned by Leon V & Estelita G Ribay, was constructed in 1900 and has undergone significant improvements over the past decades. Most notably, the building completed its mandatory soft-story retrofit in 2017 (Tier 3) and installed a comprehensive fire safety system upgrade that included new control panels, detectors, and pull stations in 2017-2024. Recent fire safety improvements include the installation of low-frequency horns in 2023-2024 to meet inspection requirements. The building has undergone substantial plumbing infrastructure improvements, including a complete replacement of metal pipes with copper piping in 2017-2018, though this work led to multiple tenant complaints about water service interruptions. Other major improvements include new washer/dryer installations in 2021, reroofing in 2014, and various electrical system upgrades.

The building has experienced several maintenance and safety issues over the years, with clustering of plumbing-related complaints in 2017-2018 regarding work being performed without proper permits, as well as ongoing hot water and heating system concerns. While most violations from the early 2000s related to fire safety and security requirements were resolved by mid-2002, there have been more recent fire safety complaints that were either found to have no merit or were quickly corrected. The property maintains an active record of addressing tenant complaints and building maintenance issues, though there have been periodic issues with garbage and debris outside the building that required city intervention.

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

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Risk rating

How 643-645 Oak St'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
16th percentile

Out of 1027 buildings in this neighborhood, 863 are predicted to be safer.

RiskiestSafest
Predicted 12-month outcome
41%
No DBI
violation
59%
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.

Number of units

The number of units affects how the model reads complaint and violation totals — more units means more potential sources.

Building size

Total floor area — a proxy for building scale and the number of systems (plumbing, electrical, HVAC) that can fail.

Neighborhood location

Precise location is a proxy for neighborhood-level risk — some SF blocks have systematically higher DBI activity.

12-Month severity forecast
No violation 17.8%
Moderate concern 29.1%
Severe concern 53.1%
Estimated probability of receiving a DBI Notice of Violation in the next 12 months at each severity level. Model: full_hgb_balanced.
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The story over time

643-645 Oak St event timeline

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

2025
Building Violation (NOV) Jul 11
Building violation
Located at unit #9 and other units.
Building Violation (NOV)Jul 11
Building violation

See all 19 events

Full history back to 2019 — violations, complaints, permits, buyouts, and fire incidents.

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Every record we have

Full data for 643-645 Oak St apartments

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

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