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3420 18Th St

Inner Mission, SF 94110 3576090 16 units · 4 fl · 2018

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 Inner Mission
Above average
avg 2.6
4
FewerMore

This building has 4 novs (7y), above the Inner Mission average of 2.6.

Rent & eviction protection

Is 3420 18Th 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 2018
2 or more units
16 units
Property type
Multi-Family Residential
Zoning
NC3
Not rent-controlled. Buildings constructed after 1978 are generally exempt from SF rent increase limits under the Costa-Hawkins Act.

Based on SF Assessor records. Not legal advice — confirm with the SF Rent Board.

Building characteristics
Units16
Floors4
Year built2018
Total area17,024 sq ft
Property typeMulti-Family Residential
Tax statusNone
Blocklot3576090
Ownership

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

Owner name
Deimon Llc
Mailing address
Michaelmamone 1875 Mission St Apt 103 San Francisco CA 94103
Last sale
011119

Landlord portfolio

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

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Augrented Insights
Initial analysis

Located at 3420 18th Street in the Inner Mission neighborhood, this property is a one-story multi-family residential building constructed in 1910, containing 16 residential units and ground floor commercial space (Brew Cha Tea Shop). The building underwent significant reconstruction between 2015-2016, replacing the original structure with a five-story building featuring 16 residential units above ground-floor retail space and parking for 8 vehicles. The construction period involved extensive improvements including new bathrooms, kitchen facilities, central furnaces, and a comprehensive fire safety system including sprinklers and alarm systems. The property has experienced several maintenance and compliance issues, with the most recent being a cluster of violations filed in October 2023 relating to smoke/carbon monoxide detector compliance, door signal devices, and fire safety documentation, though all these violations were abated by November 28, 2023.

Historically, the building faced various challenges including some concerning conditions in 2009 with dry rot and wildlife intrusion, and a 2002 complaint regarding a vent cover and sidewalk stability. More recently, there have been recurring issues with graffiti and exterior maintenance, as evidenced by multiple 311 calls in 2024-2025. The building's fire safety systems have been an ongoing focus, with multiple complaints and violations recorded between 2005 and 2023, though most have been addressed promptly. Despite these issues, the building's recent history shows active management attention to compliance matters, with most violations being promptly addressed according to the available records.

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

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Risk rating

How 3420 18Th 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
13th percentile

Out of 2380 buildings in this neighborhood, 2071 are predicted to be safer.

RiskiestSafest
Predicted 12-month outcome
32%
No DBI
violation
68%
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 25.7%
Moderate concern 37.5%
Severe concern 36.8%
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

3420 18Th St event timeline

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

2026
311 Request Apr 04
Not offensive
parking meter
311 RequestFeb 02
Garbage and debris

See all 13 events

Full history back to 2021 — violations, complaints, permits, buyouts, and fire incidents.

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Every record we have

Full data for 3420 18Th 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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