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727 21St Ave

Central Richmond, SF 94121 1664004 2 units · 2 fl · 1923

A handful of records on file over the last seven years, and our model puts this building at a low risk of further maintenance problems in the next 12 months. A few records worth reading before you sign. Check whether they were closed out, and ask what was actually fixed.

NOVs (7y) vs. neighborhood
Records already on file, against a typical building in Central Richmond — not a forecast
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.

The bar and the rating point different ways because they measure different things: the bar counts DBI violations already on file, the rating forecasts the next 12 months.

Rent & eviction protection

Is 727 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 1923
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.

Statewide backstop · AB 1482

California Tenant Protection Act of 2019

Even when a building isn't covered by local rent stabilization, the statewide Tenant Protection Act (AB 1482) may still apply. It caps annual rent increases and requires the landlord to state a legal reason to end most tenancies.

15+ years since occupancy
Built 1923
Annual rent increase cap
5% + CPI, max 10%
Just-cause eviction
After 12 months
Local rent control likely takes priority. This building appears to fall under the local ordinance above, which is stronger than AB 1482. Where a local just-cause ordinance applies, its rules govern instead of the state cap.

AB 1482 does not apply to single-family homes and condos unless owned by a corporation, REIT, or an LLC with a corporate member; to owner-occupied duplexes; or to deed-restricted affordable housing. The Act is in effect until January 1, 2030. Not legal advice — see the California landlord–tenant guide.

Building characteristics
Units2
Floors2
Year built1923
Total area4,225 sq ft
Property typeMulti-Family Residential
Tax statusHome Owners
Blocklot1664004
Ownership

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

Mailing address
Ng Duck Yuen & Wu Mandy Man 727 21St Ave San Francisco CA 94121
Last sale
January 26, 1995

Landlord portfolio

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

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Augrented Insights
Initial analysis

The two-unit multi-family residential building at 727 21st Avenue, owned by Duck Y Ng & Mandy M Wu Lvg, was constructed in 1923 as a two-story flats and duplex structure in San Francisco's Central Richmond neighborhood. The building has undergone several significant modifications over the years, including a completed basement renovation in 1995 that added a guest room, work room, playroom, and bathroom. In 2010, electrical work was completed involving the installation of a 60-amp house meter for both 727 and 729 21st Avenue. A building complaint was filed in October 2021 regarding unpermitted interior work that appeared to involve kitchen remodeling, though this complaint is currently listed as not active.

The property has experienced recurring issues with parking violations in recent years, with multiple documented cases of driveway blocking between 2021 and 2024, resulting in citations being issued. Other notable incidents include a sewer backup in March 2015 that was resolved by the Public Utilities Commission, and various maintenance and safety issues documented through 311 calls between 2019 and 2024, including a noise complaint, graffiti removal, and a sidewalk parking violation. An expired roofing permit from 1994 is also on record, though this is likely outdated given the age of the permit. While the building has experienced several maintenance and compliance-related issues over the years, particularly in recent years regarding unpermitted work and parking violations, most documented complaints and incidents have been addressed through proper channels.

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

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Risk rating

How 727 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

Lower risk — safer than most nearby

DBI rarely finds violations here. Strong maintenance history and a clean complaint record.

Typical — about average for the neighborhood

Some past violations or complaints on record. Worth asking the landlord about any open issues before signing.

Higher risk — riskier than most nearby

Elevated violation and complaint history. DBI has found issues here before and is statistically likely to again.

Neighborhood percentile
22ndpercentile

Out of 2250 buildings in this neighborhood, 1755 are predicted to be safer. The band is relative to this neighborhood, so a share of every neighborhood falls in each colour.

RiskiestSafest
Predicted 12-month outcome
75%
No DBI
violation
25%
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.

DBI tenant complaints (past 7 years)

Formal complaints tenants filed with DBI about this building over 7 years.

Permit rate, owner's portfolio

Per-building permit rate across the owner's portfolio.

Construction spend, owner's portfolio

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

12-Month risk forecast
Low failure risk 25%
Estimated probability of receiving a DBI Notice of Violation in the next 12 months. Model: full_hgb_balanced.
Apartment reviews

727 21St Ave apartment reviews

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On the map

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The story over time

727 21St Ave event timeline

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

2024
311 Request Aug 10
Blocking driveway cite tow
Parking Enforcement

See all 2 events

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

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Every record we have

Full data for 727 21St Ave apartments

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

Side by side

How 727 21St Ave compares to the neighborhood

This building against comparable properties in Central Richmond. Toggle filters to narrow the peer group.

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Cancel anytime · Data sourced from SF Open Data, DBI, SFFD, SF Rent Board & Planning

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