Free SF apartment background check

125 Mason St

Union Square, SF 94102 0331018

This building has a substantial enforcement record over the last seven years, and our model predicts continuing maintenance failures over the next 12 months. Read the records below before you sign. Ask which issues were resolved, get repair commitments in writing, and inspect the unit yourself.

NOVs (7y) vs. neighborhood
Records already on file, against a typical building in Union Square — not a forecast
Above average
avg 7.1
12
FewerMore

This building has 12 novs (7y), above the Union Square average of 7.1.

Rent & eviction protection

Is 125 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 unknown
2 or more units
? units
Property type
Multi-Family Residential
Zoning
C3G
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.

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
Unknown
Annual rent increase cap
5% + CPI, max 10%
Just-cause eviction
After 12 months
Coverage unclear. AB 1482 turns on the certificate-of-occupancy date and property type — confirm the year the building was completed.

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
Units
Floors
Year built
Total area
Property typeMulti-Family Residential
Tax statusWelfare
Blocklot0331018
Ownership

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

Mailing address
John Stewart Co, Inc 333 Taylor St San Francisco CA 94102
Last sale

Landlord portfolio

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

Unlock complete report
Augrented Insights
Initial analysis

125 Mason Street is a multi-family residential building in Union Square, classified as an apartment with 15 or more units, though the exact number of units is currently listed as 0. The building has experienced several significant maintenance and safety issues in recent months, including multiple fire safety violations and equipment concerns. Most notably, there have been recurring problems with the elevator (reported to malfunction every four months), ADA accessibility issues at the entrance, and various maintenance problems including electrical outages and plumbing issues in individual units. Between 2023 and 2024, multiple complaints were filed regarding building systems and safety equipment, including non-functional emergency systems, missing smoke detectors, and an expired elevator permit. The building underwent substantial water damage repairs in 2021 costing approximately $1.4 million, and there have been several fire safety compliance issues requiring attention, including recent violations related to sleeping area requirements, fire alarm systems, and maintenance documentation.

The property's maintenance history shows regular updates to essential systems, including boiler replacements and fire safety improvements. A series of building permits and plumbing work demonstrates ongoing attention to infrastructure maintenance, though some recent complaints suggest that certain systems may require further attention. The building's fire safety record shows a pattern of alarm system activations and some documented violations requiring correction, though many of these issues appear to have been addressed based on "abated" status in violation records. Recent 311 calls around the property have primarily related to street-level issues rather than building-specific problems, though some concerns about the surrounding area are noted. The most recent building complaint from August 2024 highlights continuing concerns about structural issues, though this complaint is currently marked as "Active."

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

Free account unlocks the full analysis — plus 2× more records across all data categories and the complete landlord portfolio.
Risk rating

How 125 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
47thpercentile

Out of 38 buildings in this neighborhood, 20 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
10%
No DBI
violation
90%
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.

DBI tenant complaints (past 7 years)

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

DBI complaint rate, owner's portfolio

Per-building complaint rate across the owner's portfolio.

DBI complaints, owner's portfolio

Complaints across all of this owner's buildings over 7 years.

12-Month risk forecast
High failure risk 90%
Estimated probability of receiving a DBI Notice of Violation in the next 12 months. Model: full_hgb_balanced.
Apartment reviews

125 Mason St apartment reviews

Real experiences from people who have lived here. Share yours to help other renters decide.

Share your experience — Help other renters by leaving an honest apartment review

Loading reviews…

On the map

Compare nearby alternatives

This building and nearby alternatives, color-coded by risk level. Click any marker to explore.

The story over time

125 Mason St event timeline

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

2026
311 Request Jul 15
Garbage and debris
furniture
Planning RecordMay 21
Request for zoning verification letter

See all 29 events

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

Unlock complete timeline
Every record we have

Full data for 125 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 125 Mason St compares to the neighborhood

This building against comparable properties in Union Square. Toggle filters to narrow the peer group.

Loading comparables…
Still apartment hunting in SF?

Look up the next apartment before you sign

Search any SF address free — no account needed to see the risk rating.

Simple pricing

Get the complete picture

Every plan unlocks the complete report: all 13 SF datasets, full history, landlord portfolio, and PDF & Excel exports.

Pay once

Report Bundle

For the buildings you're deciding on right now

$10one time

3premium reports

$3.33 per report · charged once, never renews

Each credit unlocks one building's premium report for 30 days.

  • 3 premium reports — AI executive summary included
  • Live data across all 27 public record types
  • 200 records per dataset
  • PDF & Excel exports included
  • Compare up to 10 buildings side-by-side
  • Credits never expire until you use them
Pay once

Apartment Hunter

For a wide search across many buildings

$39one time

30premium reports

$1.30 per report · charged once, never renews

Each credit unlocks one building's premium report for 30 days.

  • 30 premium reports — AI executive summary included
  • Live data across all 27 public record types
  • 200 records per dataset
  • PDF & Excel exports included
  • Compare up to 10 buildings side-by-side
  • Credits never expire until you use them

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

Watch 125 Mason St
Get alerted the moment a new violation or complaint is filed.