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509-511 18Th Ave

Central Richmond, SF 94121 1561001B 2 units · 2 fl · 1917

This building has a higher-than-average number of open problems nearby. Few open issues; problems get fixed quickly. A reasonable bet for a smooth tenancy.

NOVs (7y) vs. neighborhood
Compared to a typical building in Central Richmond
At or below average
avg 0.5
0
FewerMore

This building has 0 novs (7y), at or below the Central Richmond average of 0.5.

Rent & eviction protection

Is 509-511 18Th 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 1917
2 or more units
2 units
Property type
Multi-Family Residential
Zoning
RH2
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 built1917
Total area2,090 sq ft
Property typeMulti-Family Residential
Tax statusNone
Blocklot1561001B
Ownership

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

Owner name
Xu Donghua & Qin Caihua
Mailing address
Xu Kevin 511 18Th Ave San Francisco CA 94121
Last sale
112503

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.

509 18th Ave, San Francisco, CA 94121
511 18th Ave, San Francisco, CA 94121
Augrented Insights
Initial analysis

The two-unit residential building at 509-511 18th Avenue in San Francisco's Central Richmond neighborhood is a two-story flats and duplex structure built in 1917, currently owned by Xu Donghua and Qin Caihua. The property has undergone several significant maintenance and improvement projects over the past three decades, including a comprehensive kitchen renovation in 1999 that involved new cabinets, sink, stove, electrical work, and countertop installation. More critically, in 1990, the building underwent important structural work that included bolting the mudsill to the foundation and repairing stairs and landing areas affected by dry rot. An attempt to secure the roof was documented in 1994 through a permitted reroofing project, though this permit ultimately expired.

In recent months (April to May 2024), the property has experienced multiple maintenance and parking-related issues. Notably, there was a sewage backup incident reported in late May 2024, which was subsequently resolved by PUC Sewer Operations. The property is also currently experiencing an unresolved issue with tree roots lifting the sidewalk, which was reported in May 2024. There has been a notable pattern of parking enforcement calls, with multiple reports of vehicles blocking driveways between April and May 2024, though most of these cases were either resolved with citations or officers being unable to locate the offending vehicles. Other municipal service calls during this period included reports of street defects and one case of an abandoned vehicle, which was towed on May 1, 2024. While these recent issues primarily relate to parking concerns and routine municipal services, the building's historical permits indicate previous attention to both cosmetic improvements and structural integrity maintenance.

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

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Risk rating

How 509-511 18Th 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
63th percentile

Out of 2250 buildings in this neighborhood, 832 are predicted to be safer.

RiskiestSafest
Predicted 12-month outcome
86%
No DBI
violation
14%
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.

Construction spend, owner's portfolio

Estimated permit value across all of this owner's buildings.

Building permits, owner's portfolio

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

Estimated permit spend (past 7 years)

Dollar value of permits pulled at this address — large recent spend can signal deferred-maintenance catch-up.

12-Month severity forecast
No violation 82.1%
Moderate concern 12.5%
Severe concern 5.3%
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

509-511 18Th Ave event timeline

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

2026
311 Request Mar 09
Blocking driveway cite tow
Parking Enforcement

See all 2 events

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

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Every record we have

Full data for 509-511 18Th Ave apartments

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

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