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3666-3670 20Th St

Mission Dolores, SF 94110 3597024 5 units · 3 fl · 1907

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 Mission Dolores
At or below average
avg 2.9
0
FewerMore

This building has 0 novs (7y), at or below the Mission Dolores average of 2.9.

Rent & eviction protection

Is 3666-3670 20Th 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 1907
2 or more units
5 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
Units5
Floors3
Year built1907
Total area4,290 sq ft
Property typeMulti-Family Residential
Tax statusNone
Blocklot3597024
Ownership

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

Owner name
Lee Aik Leong
Mailing address
3670 20th St San Francisco CA 94110
Last sale
071613

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.

3668 20th St, San Francisco, CA 94110
3670 20th St, San Francisco, CA 94110
3666 20th St, San Francisco, CA 94110
Augrented Insights
Initial analysis

The 5-unit, 3-story multi-family residential building at 3666-3670 20th Street in Mission Dolores, owned by Lee Aik Leong, has undergone several significant improvements since its construction in 1907. Most notably, the building completed mandatory seismic upgrades in 2019 as a Tier 3 soft-story retrofit, including the installation of new concrete footings at a cost of approximately $75,000, demonstrating compliance with current safety standards. Additional major renovations include a complete reroofing project in 2014 and a significant unit renovation in 2008 (Unit 3670) that encompassed kitchen and bathroom remodeling, fireplace installation, and associated electrical and plumbing work valued at $25,000.

The building's compliance history shows attention to safety requirements, with previous fire safety violations from a 2002 routine inspection promptly addressed within one month, including the installation of smoke detectors, fire escape repairs, and central alarm system certifications. Recent maintenance concerns primarily relate to street-level issues rather than building conditions, with multiple 311 calls in 2023 (most recently in January 2024) reporting street cleaning needs, waste removal, and tree maintenance, all of which were resolved. The building has no active complaints or violations on record since 2002, and all routine fire and UL certification inspections between 2016-2018 were determined to have "No Merit."

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

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Risk rating

How 3666-3670 20Th 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
46th percentile

Out of 799 buildings in this neighborhood, 431 are predicted to be safer.

RiskiestSafest
Predicted 12-month outcome
64%
No DBI
violation
36%
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.

Neighborhood location

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

Building age

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

12-Month severity forecast
No violation 37.9%
Moderate concern 22.0%
Severe concern 40.1%
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

3666-3670 20Th St event timeline

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

2023
311 Request Mar 11
Bulky items
Furniture

See all 3 events

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

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Every record we have

Full data for 3666-3670 20Th 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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