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100 20Th Ave

Lake Street, SF 94121 1379034 9 units · 3 fl · 1916

This building has far more open problems than almost any other in the neighborhood. A handful of unresolved issues. Worth a careful walk-through and pointed questions.

NOVs (7y) vs. neighborhood
Compared to a typical building in Lake Street
Above average
avg 0.6
4
FewerMore

This building has 4 novs (7y), above the Lake Street average of 0.6.

Rent & eviction protection

Is 100 20Th 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 1916
2 or more units
9 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
Units9
Floors3
Year built1916
Total area7,848 sq ft
Property typeMulti-Family Residential
Tax statusNone
Blocklot1379034
Ownership

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

Owner name
Lin Wen K
Mailing address
4273 California St San Francisco CA 94118
Last sale
052595

Landlord portfolio

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

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Augrented Insights
Initial analysis

The three-story, 9-unit multi-family residential building at 100 20th Avenue, built in 1916, has undergone several significant improvements and faced various maintenance challenges over the years. Most recently, in November 2024, the building initiated the replacement of its fire alarm system to comply with current fire marshal requirements. The property completed its mandatory soft-story seismic retrofit in 2018, achieving Tier 3 compliance with a Certificate of Final Completion issued. However, the building has experienced recurring issues with water damage and building maintenance, with multiple complaints documented between 2006 and 2022 regarding leaking windows, plumbing problems, and mold growth. A major cluster of building violations was recorded in January 2022, including issues with fire safety systems, sink and cabinet repairs, and window maintenance, though these were subsequently abated by July 2022.

The building's fire safety systems have been an ongoing area of attention, with violations recorded in 2023 and 2024 specifically related to alarm system maintenance, both of which were eventually corrected. Historical maintenance work includes a kitchen remodel completed in 2022, electrical grounding improvements in 2018, and various structural and cosmetic repairs dating back to the 1980s, including stucco repair and painting in 1985. The property has also shown responsiveness to external issues with multiple 311 calls in recent years regarding sidewalk parking, tree maintenance, and street cleaning, with most cases being resolved through appropriate channels.

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

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Risk rating

How 100 20Th 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
5th percentile

Out of 660 buildings in this neighborhood, 627 are predicted to be safer.

RiskiestSafest
Predicted 12-month outcome
39%
No DBI
violation
61%
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 size

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

DBI tenant complaints (past 7 years)

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

12-Month severity forecast
No violation 29.6%
Moderate concern 47.0%
Severe concern 23.5%
Estimated probability of receiving a DBI Notice of Violation in the next 12 months at each severity level. Model: full_hgb_balanced.
Apartment reviews

100 20Th Ave apartment reviews

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The story over time

100 20Th Ave event timeline

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

2026
311 Request Jan 26
Sidewalk defect
lifted sidewalk tree roots

See all 18 events

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

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Every record we have

Full data for 100 20Th 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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