Free SF apartment background check

336-340 12Th Ave

Inner Richmond, SF 94118 1443033 2 units · 2 fl · 1914

This building has significantly more problems than most nearby buildings. Few open issues; problems get fixed quickly. A reasonable bet for a smooth tenancy.

NOVs (7y) vs. neighborhood
Compared to a typical building in Inner Richmond
At or below average
avg 0.9
0
FewerMore

This building has 0 novs (7y), at or below the Inner Richmond average of 0.9.

Rent & eviction protection

Is 336-340 12Th Ave 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 1914
2 or more units
2 units
Property type
Multi-Family Residential
Zoning
RM1
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
Units2
Floors2
Year built1914
Total area1,243 sq ft
Property typeMulti-Family Residential
Tax statusHome Owners
Blocklot1443033
Ownership

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

Owner name
Lam Calvin Chun Mau
Mailing address
338 12th Ave San Francisco CA 94118
Last sale
081004

Landlord portfolio

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

Unlock complete report
Multiple entrances & addresses

Included addresses

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

340 12th Ave, San Francisco, CA 94118
336 12th Ave, San Francisco, CA 94118
338 12th Ave, San Francisco, CA 94118
Augrented Insights
Initial analysis

The property at 336-340 12th Avenue is a 2-unit, 2-story multi-family residential building constructed in 1914, currently owned by Calvin Chun Mau Lam. The building has undergone several significant modifications and improvements over the years, with the most recent being a completed rear yard stair installation to the second floor in June 2023, costing $6,000. Notable safety improvements include the 2009 installation of fire sprinklers in the rear building ($3,500), and the building underwent soundproofing enhancements in 2015 with the addition of resilient channels and new sheetrock ($2,800). The property has a concerning pattern of unauthorized modifications, particularly regarding a disputed roof deck installation, with multiple complaints filed between 2020 and 2024 about work being conducted without proper permits or inspections. The building's history includes one major compliance issue from 2000-2004 regarding an unauthorized conversion of ground floor spaces into living areas, though this violation was eventually abated.

The property has experienced periodic maintenance issues typical of older buildings, including multiple sewage backup incidents (recorded in 2010 and 2021), as well as exterior maintenance concerns such as a collapsed sidewalk (2012) and various reports of loose garbage (2015, 2020). Historical records indicate attempts to convert the garage space into a childcare center and the addition of exterior stairs, though it's unclear if these projects were fully realized. The most recent planning records show ongoing interest in expanding the building envelope, with previous proposals for significant additions including a new two-story-over-garage structure with roof deck, though it's important to note that such proposals were only informational and not confirmed as executed. The building also retains some historical commercial use, having housed "Dong Dong Day Care" in 2012, though this operation appears to have been addressed and resolved.

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 336-340 12Th Ave'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
20th percentile

Out of 1723 buildings in this neighborhood, 1378 are predicted to be safer.

RiskiestSafest
Predicted 12-month outcome
68%
No DBI
violation
32%
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.

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 47.6%
Moderate concern 35.8%
Severe concern 16.6%
Estimated probability of receiving a DBI Notice of Violation in the next 12 months at each severity level. Model: full_hgb_balanced.
Apartment reviews

336-340 12Th Ave 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.

Buildings nearby
Loading…
The story over time

336-340 12Th Ave event timeline

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

2025
Planning Record Sep 14
1. CONVERT A PORTION OF THE FIRST-FLOOR GARAGE INTO LIVING SPACE. 2. CONVERT THE EXISTING FIRST-FLOOR LAUNDRY ROOM INTO A HALF BATH. 3. RELOCATE THE GAS TANKLESS WATER HEATER FROM THE FIRST-FLOOR GARAGE TO THE CORRIDOR. 4. CONVERT A PORTION OF THE EXISTING FOURTH-FLOOR FAMILY ROOM INTO A NEW DEN. 5. REMODEL THE FOURTH-FLOOR BEDROOM WITH A REVISED LAYOUT.
Under Review
Building PermitAug 20
Convert part of the 1st floor garage into living space; convert existing 1st floor laundry room into a half bath; gas tankless water heater relocation from 1st floor garage to corridor; convert part of the existing 4th floor family rm into a new den; 4th fl. bedroom remodel with layout change.

See all 8 events

Full history back to 2020 — violations, complaints, permits, buyouts, and fire incidents.

Unlock complete timeline
Every record we have

Full data for 336-340 12Th Ave apartments

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

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.

Report Bundle

For the buildings you're deciding on right now

$10 one-time

~$3.33 per building. No subscription ever. Each credit unlocks one building's premium report for 30 days.

  • 3 full AI-powered reports
  • Download PDF reports
  • Advanced safety analysis
  • Compare multiple buildings
  • Credits never expire until you use them
  • Full public records (200 rows per dataset)
Buy 3 Reports — $10

Apartment Hunter

For a wide search across many buildings

$39 one-time

30 reports — ~$1.30 each. No subscription ever.

  • 30 full AI-powered reports
  • Download PDF reports
  • Advanced safety analysis
  • Compare multiple buildings
  • Credits never expire until you use them
  • Full public records (200 rows per dataset)
Buy 30 Reports — $39

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

Watch 336-340 12Th Ave
Get alerted the moment a new violation or complaint is filed.