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475 21St Ave

Central Richmond, SF 94121 1523016 2 units · 2 fl · 1916

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 475 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 1916
2 or more units
2 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
Units2
Floors2
Year built1916
Total area2,490 sq ft
Property typeMulti-Family Residential
Tax statusNone
Blocklot1523016
Ownership

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

Owner name
Chang Tony & Tang Wendy
Mailing address
2134 9th Ave Oakland CA 94606
Last sale
110703

Landlord portfolio

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

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Augrented Insights
Initial analysis

The two-unit residential building at 475 21st Avenue, owned by Tony Chang and Wendy Tang, is a two-story flats and duplex structure built in 1916 in San Francisco's Central Richmond neighborhood. The property has undergone several significant maintenance and improvement projects over the years, with the most recent being a $10,000 reroofing project completed in 2022. Prior to this, there were multiple window replacements in 2004, including one project completed ($4,000) and another that expired ($3,000), plus an earlier reroofing project from 1994. Historical records indicate attention to structural maintenance, with dry rot removal completed in 1986.

The building has experienced minimal internal issues, with only one building code complaint noted in 2004 regarding unpermitted remodeling work, which was promptly addressed within two weeks. More recently, there has been a recurring issue with driveway blockage, particularly during 2021-2024, with multiple parking enforcement calls, though most resulted in officers being unable to locate the offending vehicles. Other public space-related incidents include noise complaints in 2019, streetlight issues in 2017, and two reports of loose garbage on the street/sidewalk in 2013, all of which were resolved through appropriate channels. The building's permit and complaint history suggests regular maintenance and prompt response to building code issues, though the recent pattern of driveway blocking incidents may indicate ongoing challenges with parking management in the area.

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

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Risk rating

How 475 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
74th percentile

Out of 2250 buildings in this neighborhood, 585 are predicted to be safer.

RiskiestSafest
Predicted 12-month outcome
88%
No DBI
violation
12%
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.

Building size

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

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 81.9%
Moderate concern 12.5%
Severe concern 5.6%
Estimated probability of receiving a DBI Notice of Violation in the next 12 months at each severity level. Model: full_hgb_balanced.
Apartment reviews

475 21St Ave apartment reviews

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The story over time

475 21St Ave event timeline

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

2022
Building Permit Jun 27
Reroofng.
$10,000 · Complete

See all 1 events

Full history back to 2022 — violations, complaints, permits, buyouts, and fire incidents.

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Every record we have

Full data for 475 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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