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446 21St Ave

Central Richmond, SF 94121 1524030 2 units · 2 fl · 1988

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 Central Richmond
At or below average
avg 0.5
0
FewerMore

This building has 0 novs (7y), at or below the Central Richmond average of 0.5.

Rent & eviction protection

Is 446 21St 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 1988
2 or more units
2 units
Property type
Multi-Family Residential
Zoning
RH2
Not rent-controlled. Buildings constructed after 1978 are generally exempt from SF rent increase limits under the Costa-Hawkins Act.

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

Building characteristics
Units2
Floors2
Year built1988
Total area3,665 sq ft
Property typeMulti-Family Residential
Tax statusNone
Blocklot1524030
Ownership

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

Owner name
Jan Lam & Diana Wong Tang R
Mailing address
Tang Diana Wong, Ttee 446 21St Ave San Francisco CA 94121
Last sale
000000

Landlord portfolio

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

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Augrented Insights
Initial analysis

The property at 446 21st Avenue in the Central Richmond neighborhood is a two-unit, two-story multi-family residential building, constructed in 1988 following the demolition of a single-family dwelling and garage in May 1986. The building, owned by Jan Lam and Diana Wong Tang R, has undergone several notable improvements over the years, including a significant solar panel installation in October 2014 comprising 20 roof-mounted PV modules (255W each) with a total system rating of 5.1kW, and a roofing project in November 2012 that cost approximately $9,000.

The building's maintenance and compliance record appears generally positive, with no major safety violations or building code issues on record. However, there have been recurring parking-related incidents in the vicinity, with three documented cases of sidewalk parking between 2017 and 2024, including a resolved citation for driveway blocking in October 2021 involving a Subaru vehicle. Street cleaning and maintenance issues have been relatively minor, with four reported cases between 2019 and 2020 concerning garbage and waste on or near the property, all of which were promptly resolved. The property's infrastructure appears to be modern, with the addition of solar power and timely roof maintenance, suggesting responsible ownership and maintenance practices.

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

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Risk rating

How 446 21St 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
98th percentile

Out of 2250 buildings in this neighborhood, 45 are predicted to be safer.

RiskiestSafest
Predicted 12-month outcome
94%
No DBI
violation
6%
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.

Construction spend, owner's portfolio

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

Estimated permit spend (past 7 years)

Dollar value of permits pulled at this address — large recent spend can signal deferred-maintenance catch-up.

Building permits, owner's portfolio

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

12-Month severity forecast
No violation 87.7%
Moderate concern 8.8%
Severe concern 3.4%
Estimated probability of receiving a DBI Notice of Violation in the next 12 months at each severity level. Model: full_hgb_balanced.
Apartment reviews

446 21St Ave apartment reviews

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The story over time

446 21St Ave event timeline

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

No dated public records on file yet.
Every record we have

Full data for 446 21St 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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