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1246 21St Ave

Central Sunset, SF 94122 1730034 3 units · 3 fl · 1990

This building has more problems than most buildings in this neighborhood. 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 Sunset
At or below average
avg 0.7
0
FewerMore

This building has 0 novs (7y), at or below the Central Sunset average of 0.7.

Rent & eviction protection

Is 1246 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 1990
2 or more units
3 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
Units3
Floors3
Year built1990
Total area5,958 sq ft
Property typeMulti-Family Residential
Tax statusNone
Blocklot1730034
Ownership

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

Owner name
Tong Yin Kai & Di-Fun Tsang
Mailing address
441 Yerba Buena Ave San Francisco CA 94127
Last sale
011014

Landlord portfolio

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

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Augrented Insights
Initial analysis

The three-unit, three-story multi-family residential building at 1246 21st Avenue in the Central Sunset neighborhood, owned by Tong Yin Kai & Di-fun Tsang, was constructed in 1990 following two completed construction projects in 1987 and 1988 that involved both horizontal and vertical extensions of the property. The building's permit history shows a sidewalk permit was issued in October 2007 for a nominal cost of $1.00.

The property has experienced recurring parking-related issues in recent years, with four documented incidents between 2018 and 2024 involving vehicles blocking driveways or parking on sidewalks, though in each case, responding officers were either unable to locate the offending vehicles or could not validate the reported issues. Additionally, there was one notable incident in February 2021 involving sewer odor complaints that were initially reported to the San Francisco Fire Department Bureau of Fire Prevention, which were later referred to another agency, and a fire-related complaint in June 2021 that was similarly referred to another agency.

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

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Risk rating

How 1246 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
27th percentile

Out of 814 buildings in this neighborhood, 594 are predicted to be safer.

RiskiestSafest
Predicted 12-month outcome
77%
No DBI
violation
23%
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.

Estimated permit spend (past 7 years)

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

Building size

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

Owner's portfolio size

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

12-Month severity forecast
No violation 73.6%
Moderate concern 15.5%
Severe concern 10.9%
Estimated probability of receiving a DBI Notice of Violation in the next 12 months at each severity level. Model: full_hgb_balanced.
Apartment reviews

1246 21St Ave apartment reviews

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The story over time

1246 21St Ave event timeline

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

2021
Fire Complaint Jun 11
Uncategorized Complaint
Referred To Another Agency

See all 1 events

Full history back to 2021 — violations, complaints, permits, buyouts, and fire incidents.

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Every record we have

Full data for 1246 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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