Free SF apartment background check

4171 23Rd St

Noe Valley, SF 94114 2804035 2 units · 2 fl · 1910

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 Noe Valley
At or below average
avg 1.2
0
FewerMore

This building has 0 novs (7y), at or below the Noe Valley average of 1.2.

Rent & eviction protection

Is 4171 23Rd 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 1910
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 built1910
Total area2,260 sq ft
Property typeMulti-Family Residential
Tax statusNone
Blocklot2804035
Ownership

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

Owner name
David Brodwin & Debra Niema
Mailing address
David Broewin & Debra Niema 4171 23Rd St San Francisco CA 94114
Last sale
042796

Landlord portfolio

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

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Augrented Insights
Initial analysis

The property at 4171 23rd Street in Noe Valley is a two-unit, two-story multi-family residential building constructed in 1910, currently owned by David Brodwin and Debra Niema. The building has undergone several significant improvements over the years, with major renovations including a complete reroofing in 2014 costing approximately $12,880, and substantial mid-level improvements in 1992 that added a half-bath and included a minor kitchen remodel. The late 1980s saw numerous interior and exterior enhancements, including the installation of a new fireplace, window replacements, bathroom remodeling, electrical upgrades, and repairs to various structural elements such as stairs, decks, and the porch. A street space permit was issued in 2018, though the cost was listed as $0.00.

Recent records from 2024-2025 indicate some maintenance issues and external incidents affecting the property, including two sewage backup incidents in February 2024 (one of which was ultimately cancelled as a duplicate) and concerns about a damaged tree that was reported as "about to fall" in February 2024. The building's external environment has experienced recurring parking issues, with multiple reports of illegal parking and abandoned vehicles between 2021 and 2025. Two instances of tree-related incidents were noted, including a fallen tree in August 2023. While some recent maintenance issues have been resolved, including a damaged tree case, the property has had limited internal building complaints or violations on record, with most recent issues being related to external factors such as parking and tree maintenance.

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

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Risk rating

How 4171 23Rd 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
71th percentile

Out of 1879 buildings in this neighborhood, 545 are predicted to be safer.

RiskiestSafest
Predicted 12-month outcome
85%
No DBI
violation
15%
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.

Neighborhood location

Precise location is a proxy for neighborhood-level risk — some SF blocks have systematically higher DBI activity.

Building age

Older buildings tend to have more maintenance challenges; SF's pre-1906 earthquake housing stock carries distinct risk.

Construction spend, owner's portfolio

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

12-Month severity forecast
No violation 77.5%
Moderate concern 12.7%
Severe concern 9.8%
Estimated probability of receiving a DBI Notice of Violation in the next 12 months at each severity level. Model: full_hgb_balanced.
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The story over time

4171 23Rd St event timeline

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

No dated public records on file yet.
Every record we have

Full data for 4171 23Rd 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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