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602 Mason St

Union Square, SF 94108 0284012 22 units · 5 fl · 1919

A handful of records on file over the last seven years, and our model predicts a high risk of further maintenance problems in the next 12 months. A few records worth reading before you sign. Check whether they were closed out, and ask what was actually fixed.

NOVs (7y) vs. neighborhood
Records already on file, against a typical building in Union Square — not a forecast
Above average
avg 7.1
8
FewerMore

This building has 8 novs (7y), above the Union Square average of 7.1.

Rent & eviction protection

Is 602 Mason 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 1919
2 or more units
22 units
Property type
Multi-Family Residential
Zoning
C3R
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.

Statewide backstop · AB 1482

California Tenant Protection Act of 2019

Even when a building isn't covered by local rent stabilization, the statewide Tenant Protection Act (AB 1482) may still apply. It caps annual rent increases and requires the landlord to state a legal reason to end most tenancies.

15+ years since occupancy
Built 1919
Annual rent increase cap
5% + CPI, max 10%
Just-cause eviction
After 12 months
Local rent control likely takes priority. This building appears to fall under the local ordinance above, which is stronger than AB 1482. Where a local just-cause ordinance applies, its rules govern instead of the state cap.

AB 1482 does not apply to single-family homes and condos unless owned by a corporation, REIT, or an LLC with a corporate member; to owner-occupied duplexes; or to deed-restricted affordable housing. The Act is in effect until January 1, 2030. Not legal advice — see the California landlord–tenant guide.

Building characteristics
Units22
Floors5
Year built1919
Total area13,499 sq ft
Property typeMulti-Family Residential
Tax statusNone
Blocklot0284012
Ownership

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

Owner name
Mailing address
Blatteis Realty-d Blatteis 44 Montgomery St Ste 1288 San Francisco CA 94104
Last sale
November 10, 1988

Landlord portfolio

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

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Multiple entrances & addresses

Included addresses

All street addresses sharing this blocklot that are covered by this report.

590 Sutter St, San Francisco, CA 94108
602 Mason St, San Francisco, CA 94108
Augrented Insights
Initial analysis

The five-story, 22-unit residential building at 602 Mason Street, constructed in 1919 and owned by Minhall Inc, currently faces several important safety and regulatory matters as of March 2024. Most notably, the building is under active violation notices relating to fire safety requirements, including the need for an updated 420 affidavit for smoke detectors and carbon monoxide alarms, a 604 affidavit for structural maintenance certification by a licensed contractor/engineer, and verification of fire escape ladder functionality. The property has experienced three fire incidents in the past seven years, though no serious injuries or damage are recorded. Recent building improvements include a completed roof replacement and an upgraded fire alarm system to meet SFFD requirements from 2019-2023, with a permitted construction cost of $80,005.

The building's recent history shows a pattern of occupancy and maintenance challenges, with multiple 311 service requests recorded in 2026 regarding excessive noise and sanitation issues, including reports of encampments and garbage. There have been five Building Inspection Division complaints in the past seven years, including a recent February 2024 complaint about expired permits and earlier complaints regarding vacant commercial space issues. Despite these concerns, the building has maintained some regulatory compliance, as evidenced by the completion of certain building permits and the absence of any active complaints related to housing code violations besides the recent safety-related citations. The property's common areas have been specifically noted in multiple complaints, with one common areas complaint currently active as of 2024.

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

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Risk rating

How 602 Mason 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

Lower risk — safer than most nearby

DBI rarely finds violations here. Strong maintenance history and a clean complaint record.

Typical — about average for the neighborhood

Some past violations or complaints on record. Worth asking the landlord about any open issues before signing.

Higher risk — riskier than most nearby

Elevated violation and complaint history. DBI has found issues here before and is statistically likely to again.

Neighborhood percentile
23rdpercentile

Out of 38 buildings in this neighborhood, 29 are predicted to be safer. The band is relative to this neighborhood, so a share of every neighborhood falls in each colour.

RiskiestSafest
Predicted 12-month outcome
8%
No DBI
violation
92%
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 risk forecast
High failure risk 92%
Estimated probability of receiving a DBI Notice of Violation in the next 12 months. Model: full_hgb_balanced.
Apartment reviews

602 Mason St apartment reviews

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On the map

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The story over time

602 Mason St event timeline

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

2026
DBI Complaint Aug 03
Date last observed: 02-aug-26; exact location: main bldg; building type: residence/dwelling stairway safety; disabled acc: elevator/lift; ; additional information: the elevator has been broken for several months. i live on the 4th floor and have injured my back transporting heavy luggage and trash bags. i’ve raised my concerns with building management on several occasions without recourse. additionally, there’s inadequate lighting in the stairwell which has led to me falling on several occasions (i always have to use the flashlight on my phone to get up and down the stairs at night).;
Housing Inspection Services
311 RequestJul 31
Other excessive noise

See all 23 events

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

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Every record we have

Full data for 602 Mason St apartments

13 SF public datasets for this parcel — permits, violations, complaints, fire records, 311 calls, planning records, and buyouts.

Side by side

How 602 Mason St compares to the neighborhood

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Cancel anytime · Data sourced from SF Open Data, DBI, SFFD, SF Rent Board & Planning

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