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4235-4237 21St St

Eureka Valley/Dolores Heights, SF 94114 2767027 2 units · 2 fl · 1977

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 Eureka Valley/Dolores Heights
At or below average
avg 1.3
0
FewerMore

This building has 0 novs (7y), at or below the Eureka Valley/Dolores Heights average of 1.3.

Rent & eviction protection

Is 4235-4237 21St 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 1977
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 built1977
Total area3,475 sq ft
Property typeMulti-Family Residential
Tax statusNone
Blocklot2767027
Ownership

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

Owner name
Au-Yeung Clayton & Verzosa
Mailing address
Au-yeung Roland & Wong Lisa 4235 21St St San Francisco CA 94114
Last sale
122019

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.

4235 21st St, San Francisco, CA 94114
4237 21st St, San Francisco, CA 94114
Augrented Insights
Initial analysis

The two-unit residential building at 4235-4237 21st Street, owned by Clayton Au-yeung and Verzosa, is a 2-story flats and duplex structure built in 1977 in the Eureka Valley/Dolores Heights neighborhood. The property has undergone several significant improvements over the years, most notably a substantial ceiling renovation in 2019 that included the installation of soundproofing insulation between the ground and first floors, covering approximately 1,400 square feet at a cost of $10,000. Earlier improvements in 2007-2008 included exterior renovations such as siding replacement, new windows installation, and deck work, along with plumbing updates including sewer line replacement and bathroom fixtures modifications. The building also had some permitted changes in 1993 involving kitchen modifications in the garage floor area, though these permits have since expired.

Recent history shows the property has experienced some ongoing maintenance issues, particularly regarding the sidewalk, with two open defect reports filed in April 2024 noting a collapsed sidewalk condition. There has also been a pattern of parking-related incidents around the property, with multiple cases of driveway blocking in 2023-2024 resulting in citations. The area has seen frequent reports of garbage and debris issues, with three such incidents recorded between August and October 2024, though all were resolved. An illegal posting incident was documented and resolved in March 2023, and there was one non-injury fire incident recorded related to a person in distress.

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

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Risk rating

How 4235-4237 21St 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
68th percentile

Out of 1278 buildings in this neighborhood, 409 are predicted to be safer.

RiskiestSafest
Predicted 12-month outcome
83%
No DBI
violation
17%
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 location

Precise location is a proxy for neighborhood-level risk — some SF blocks have systematically higher DBI activity.

Neighborhood (ZIP code)

The ZIP code captures local housing market and enforcement patterns that affect all buildings in the area.

Property class: multi-family flat

2–4 unit flats (class F) are a common SF building type with their own maintenance and complaint patterns.

12-Month severity forecast
No violation 65.5%
Moderate concern 16.2%
Severe concern 18.4%
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

4235-4237 21St St event timeline

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

2019
Building Permit Dec 02
Remove / replace ceiling from ground fl to 1st fl w/ sound proofing insulation (appox 14oo sq ft)
$10,000 · Issued

See all 1 events

Full history back to 2019 — violations, complaints, permits, buyouts, and fire incidents.

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Every record we have

Full data for 4235-4237 21St 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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