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3487-3497 21St St

Eureka Valley/Dolores Heights, SF 94110 3618037 6 units · 3 fl · 1909

This building has significantly more problems than most nearby buildings. A handful of unresolved issues. Worth a careful walk-through and pointed questions.

NOVs (7y) vs. neighborhood
Compared to a typical building in Eureka Valley/Dolores Heights
Above average
avg 1.3
4
FewerMore

This building has 4 novs (7y), above the Eureka Valley/Dolores Heights average of 1.3.

Rent & eviction protection

Is 3487-3497 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 1909
2 or more units
6 units
Property type
Multi-Family Residential
Zoning
RH3
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
Units6
Floors3
Year built1909
Total area6,114 sq ft
Property typeMulti-Family Residential
Tax statusNone
Blocklot3618037
Ownership

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

Owner name
Robert J Maron Living Trust
Mailing address
3043 Sheldon Dr Richmond CA 94803
Last sale
000000

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.

3487 21st St, San Francisco, CA 94110
3493 21st St, San Francisco, CA 94110
3491 21st St, San Francisco, CA 94110
3489 21st St, San Francisco, CA 94110
3495 21st St, San Francisco, CA 94110
3497 21st St, San Francisco, CA 94110
Augrented Insights
Initial analysis

The three-story, six-unit multi-family residential building at 3487-3497 21st Street, owned by the Robert J Maron Living Trust, was constructed in 1909 in the Eureka Valley/Dolores Heights neighborhood. The building's recent history shows a significant cluster of safety compliance issues in December 2022, when multiple building violations were filed regarding fire safety equipment and documentation, including smoke/carbon monoxide detector compliance and fire extinguisher maintenance. These violations were all abated by January 27, 2023. The building underwent several maintenance and infrastructure upgrades over the years, including reroofing in 1995, electrical work in 2003 (though this permit expired), and the removal of wireless antenna equipment in 2013-2015, when the property transitioned from hosting multiple antennas to retaining only one OTARD antenna. Historical records show routine apartment inspections in 2001 and 2007, with no significant issues reported during those times.

The property has experienced several residential-related incidents, though none resulted in significant damage or injuries. These include multiple false alarm activations, a carbon monoxide detector activation, and a water leak incident, all recorded by the fire department. The most recent activity around the property, as documented through 311 calls, primarily involves street and sidewalk maintenance issues, including reports of illegal postings, garbage and debris concerns, and some parking-related complaints. A notable complaint was filed in October 2022 regarding construction activity and related street blockage, though this was abated within a week. While the building has had its share of maintenance issues, most have been promptly addressed, and there are no currently active violations or complaints on record.

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

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Risk rating

How 3487-3497 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
11th percentile

Out of 1278 buildings in this neighborhood, 1137 are predicted to be safer.

RiskiestSafest
Predicted 12-month outcome
43%
No DBI
violation
57%
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.

Number of units

The number of units affects how the model reads complaint and violation totals — more units means more potential sources.

DBI tenant complaints (past 7 years)

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

Neighborhood location

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

12-Month severity forecast
No violation 27.4%
Moderate concern 52.3%
Severe concern 20.3%
Estimated probability of receiving a DBI Notice of Violation in the next 12 months at each severity level. Model: full_hgb_balanced.
Apartment reviews

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The story over time

3487-3497 21St St event timeline

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

2025
311 Request Jul 20
Not offensive
pole
311 RequestApr 13
Parking on sidewalk

See all 9 events

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

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Every record we have

Full data for 3487-3497 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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