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3170-3180 21St St

Inner Mission, SF 94110 3610018 7 units · 3 fl · 1900

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
12
FewerMore

This building has 12 novs (7y), above the Inner Mission average of 2.6.

Rent & eviction protection

Is 3170-3180 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 1900
2 or more units
7 units
Property type
Multi-Family Residential
Zoning
NC3
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
Units7
Floors3
Year built1900
Total area7,358 sq ft
Property typeMulti-Family Residential
Tax statusNone
Blocklot3610018
Ownership

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

Owner name
Antonio & Rita Castellucci
Mailing address
Antonio & Rita Castellucci 1757 Union Street San Francisco CA 94123
Last sale
080703

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.

3172 21st St, San Francisco, CA 94110
3170 21st St, San Francisco, CA 94110
3176 21st St, San Francisco, CA 94110
3180 21st St, San Francisco, CA 94110
3178 21st St, San Francisco, CA 94110
3174 21st St, San Francisco, CA 94110
Augrented Insights
Initial analysis

The three-story multi-family residential building at 3170-3180 21st Street in San Francisco's Inner Mission neighborhood, owned by Antonio & Rita Castellucci, was constructed in 1900 and contains 7 units. The property has experienced recurring maintenance issues over the past several years, with the most significant cluster of violations and complaints emerging in late 2017, including active citations for sanitation problems, lack of carbon monoxide/smoke detectors, plumbing issues, building code compliance, and structural maintenance. A serious structural rot problem was identified in March 2017, though this complaint was marked as not active by June 2017. More recently, the building is reported to be non-compliant with the soft story seismic safety requirements, with a complaint filed in December 2018 regarding failure to comply with Tier 4 soft story regulations. The building's maintenance history shows several exterior stair repairs across different years (2003, 2018) and various renovation works, including a 2000 project to add commercial stores to the ground floor. The property has been subject to multiple routine housing inspections over the years, revealing persistent maintenance concerns, particularly regarding building systems and structural elements.

Recent records from 2023 and 2024 show ongoing attention to building maintenance and surrounding areas, including multiple reports of garbage and debris issues that have been resolved. There are also two active tree maintenance requests from 2023-2024. While some historical problems have been addressed through various permits and repairs, including exterior stair work and compliance-related renovations, the outstanding violations from 2017 and the soft story non-compliance status represent the most significant current concerns regarding building conditions and regulatory compliance.

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

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Risk rating

How 3170-3180 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
19th percentile

Out of 2380 buildings in this neighborhood, 1928 are predicted to be safer.

RiskiestSafest
Predicted 12-month outcome
42%
No DBI
violation
58%
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.

Building size

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

Notices of Violation, owner's portfolio

DBI NOVs across all buildings this owner is registered on — a signal of systemic maintenance issues across the portfolio.

Neighborhood (ZIP code)

The ZIP code captures local housing market and enforcement patterns that affect all buildings in the area.

12-Month severity forecast
No violation 10.4%
Moderate concern 83.8%
Severe concern 5.8%
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

3170-3180 21St St event timeline

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

2025
Fire Complaint Jul 08
Alarm Systems
Violation Issued

See all 1 events

Full history back to 2025 — violations, complaints, permits, buyouts, and fire incidents.

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Every record we have

Full data for 3170-3180 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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