Free SF apartment background check

1119-1121 Mason St

Nob Hill, SF 94108 0213002A 2 units · 2 fl · 1940

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 Nob Hill
At or below average
avg 2.4
0
FewerMore

This building has 0 novs (7y), at or below the Nob Hill average of 2.4.

Rent & eviction protection

Is 1119-1121 Mason 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 1940
2 or more units
2 units
Property type
Multi-Family Residential
Zoning
RM3
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
Units2
Floors2
Year built1940
Total area2,962 sq ft
Property typeMulti-Family Residential
Tax statusHome Owners
Blocklot0213002A
Ownership

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

Owner name
Chan Walter & Li Yan
Mailing address
1119 Mason St San Francisco CA 94108
Last sale
041499

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.

1121 Mason St, San Francisco, CA 94108
1119 Mason St, San Francisco, CA 94108
Augrented Insights
Initial analysis

The two-unit residential building at 1119-1121 Mason Street in Nob Hill, owned by Walter Chan and Yan Li, is a two-story flats and duplex structure dating back to 1940. The property has undergone several significant maintenance and repair work over the past decades, including a complete stairway replacement on the right side of the house in 2014 (cost: $10,000), re-roofing work in 1995 (permit expired), and concrete footing repairs in the garage area completed in 1991.

The building has experienced recurring sewer-related issues, with documented sewage backups through a 4-inch vent occurring in 2018, 2019, and again in 2020-2021, suggesting an ongoing plumbing infrastructure concern despite these incidents being marked as resolved through proper work orders. Additional incidents affecting the property environment included a water main break in December 2010, maintenance on damaged trees in October 2018 (hanging limb) and August 2019 (fallen tree), and one instance of offensive graffiti on a sign in March 2018 that was addressed by the sign shop. An abandoned vehicle was reported near the property in May 2011, though it was resolved when officers arrived at the scene. While the building's major structural elements have received periodic attention, the recurring nature of sewer issues stands out as a notable pattern in the building's maintenance history.

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

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Risk rating

How 1119-1121 Mason 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
92th percentile

Out of 1125 buildings in this neighborhood, 90 are predicted to be safer.

RiskiestSafest
Predicted 12-month outcome
87%
No DBI
violation
13%
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.

Construction spend, owner's portfolio

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

Building permits, owner's portfolio

Permits pulled across all of this owner's buildings over 7 years.

12-Month severity forecast
No violation 79.7%
Moderate concern 14.1%
Severe concern 6.2%
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

1119-1121 Mason St event timeline

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

2026
Building Permit May 27
Re-roofing: remove and replace roofing material / existing roofing material (in-kind)
$43,900 · Issued

See all 6 events

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

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Every record we have

Full data for 1119-1121 Mason St 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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