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421 Union St

Telegraph Hill, SF 94133 0115052 9 units · 3 fl · 1906

This building has far more open problems than almost any other in the neighborhood. Renters here report frequent, slow-to-fix problems. Get repair promises in writing and check the unit before signing.

NOVs (7y) vs. neighborhood
Compared to a typical building in Telegraph Hill
At or below average
avg 1.2
0
FewerMore

This building has 0 novs (7y), at or below the Telegraph Hill average of 1.2.

Rent & eviction protection

Is 421 Union 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 1906
2 or more units
9 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
Units9
Floors3
Year built1906
Total area4,650 sq ft
Property typeMulti-Family Residential
Tax statusNone
Blocklot0115052
Ownership

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

Owner name
Lee Marcus
Mailing address
783 11th Ave San Francisco CA 94118
Last sale
012699

Landlord portfolio

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

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Augrented Insights
Initial analysis

The 421 Union Street building is a 9-unit, 3-story multi-family residential apartment complex located in Telegraph Hill, built in 1906 and currently owned by Lee Marcus. The property has undergone several significant safety upgrades in recent years, most notably the fire alarm system improvements completed in 2022-2023, which included the installation of low frequency sounders, smoke detectors, and other notification devices to comply with San Francisco Fire Code requirements. The building has also completed mandatory soft-story seismic improvements (Tier 3) with a completion notice issued, and underwent reroofing work in early 2023.

The property has experienced recurring fire safety issues over the years, with multiple fire alarm system violations and complaints dating back to at least 2008, including a 2019 violation for alarm system maintenance that was subsequently abated. Historical compliance issues were noted in 2005 regarding fire extinguishers and fire escape ladders, though these were resolved by June 2005. Other notable past issues include a 2011 complaint about peeling lead paint on the south-facing wall, which was addressed by 2013, and a 2017 complaint regarding a blocked second entry door, which was resolved within two months. The building has maintained active compliance with various safety requirements since these issues were addressed, as evidenced by recent completion of fire safety upgrades and the resolution of past violations.

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

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Risk rating

How 421 Union 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
8th percentile

Out of 684 buildings in this neighborhood, 629 are predicted to be safer.

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

Building age

Older buildings tend to have more maintenance challenges; SF's pre-1906 earthquake housing stock carries distinct risk.

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 9.9%
Moderate concern 18.8%
Severe concern 71.3%
Estimated probability of receiving a DBI Notice of Violation in the next 12 months at each severity level. Model: full_hgb_balanced.
Apartment reviews

421 Union St apartment reviews

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The story over time

421 Union St event timeline

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

2025
311 Request Nov 03
Parking on sidewalk
Parking Enforcement
311 RequestOct 09
Toters left out 24x7

See all 11 events

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

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Every record we have

Full data for 421 Union 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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