4239 21St St
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.
This building has 0 novs (7y), at or below the Eureka Valley/Dolores Heights average of 1.3.
Is 4239 21St 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.
Based on SF Assessor records. Not legal advice — confirm with the SF Rent Board.
| Units | 2 |
|---|---|
| Floors | 2 |
| Year built | 1977 |
| Total area | 3,475 sq ft |
| Property type | Multi-Family Residential |
| Tax status | Home Owners |
| Blocklot | 2767026 |
Registered owner per SF Assessor-Recorder (secured roll).
Landlord portfolio
Other SF properties this owner holds, with risk grades for each.
Unlock complete reportThe two-unit residential building at 4239 21st Street in the Eureka Valley/Dolores Heights neighborhood, owned by Albert Siu-lun, is a two-story flats and duplex structure built in 1977. The property has undergone several significant exterior improvements over the past two decades, with the most recent work completed in August 2023 involving the installation of new vinyl windows and a patio door at the rear of the building, representing a $6,130 investment. In September 2020, the building underwent substantial exterior maintenance, with weather-damaged siding replaced and new James Hardie lap siding installed at both the back and side of the structure at a cost of $8,800. An earlier exterior repair project from May 2005 addressed both siding issues and repairs to the rear exterior stairs, costing $4,500.
AI-generated · may contain errors · check the source data tables below
How 4239 21St 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.
Out of 1278 buildings in this neighborhood, 358 are predicted to be safer.
violation
likely
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.
4239 21St 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…
Compare nearby alternatives
This building and nearby alternatives, color-coded by risk level. Click any marker to explore.
4239 21St St event timeline
Violations, complaints, fire incidents, permits, and buyouts — most recent records in order.
See all 2 events
Full history back to 2020 — violations, complaints, permits, buyouts, and fire incidents.
Unlock complete timelineFull data for 4239 21St St apartments
13 SF public datasets for this parcel — permits, violations, complaints, fire records, 311 calls, planning records, and buyouts.
What this is
Permits issued by the SF Department of Building Inspection for new construction, alterations, and repairs. Includes estimated cost and current permit status.
| Permit # | Description | Cost | Filed | Status |
|---|---|---|---|---|
| Loading… | ||||
What this is
Plumbing permit applications filed with the SF Department of Building Inspection. Covers plumbing installation, repair, and replacement work.
| Permit # | Description | Filed | Status |
|---|---|---|---|
| Loading… | |||
What this is
Electrical permit applications filed with the SF Department of Building Inspection. Covers electrical wiring, panel upgrades, and related work.
| Permit # | Description | Filed | Status |
|---|---|---|---|
| Loading… | |||
What this is
Notices of Violation issued by the SF Department of Building Inspection for code violations. Unresolved notices can escalate to legal action.
| Date Filed | Complaint # | Description | Item | Category | Status |
|---|---|---|---|---|---|
| Loading… | |||||
What this is
Complaints filed with the SF Department of Building Inspection about code violations. Tracks the complaint lifecycle from filing through abatement or referral.
| Complaint # | Date Filed | Date Abated | Division | Status | Description |
|---|---|---|---|---|---|
| Loading… | |||||
What this is
Planning Department project entitlements — discretionary review, conditional use, variances, and environmental review for this parcel.
| Address | Opened | Closed | Status | Description | Applicant |
|---|---|---|---|---|---|
| Loading… | |||||
What this is
Planning Department administrative and compliance records that are not full project entitlements — pre-application meetings, code violations, and referrals.
| Address | Opened | Closed | Status | Description | Applicant |
|---|---|---|---|---|---|
| Loading… | |||||
What this is
SFFD fire incidents geo-joined to this parcel. Covers structure fires, alarms, and emergency responses with injury and fatality counts.
| Date | Situation | Civilian Injuries | Civilian Fatalities |
|---|---|---|---|
| Loading… | |||
What this is
Fire code violations issued by the SFFD. Tracks corrective actions required and resolution status for fire safety code enforcement.
| Violation Date | Description | Corrective Action | Status | Close Date |
|---|---|---|---|---|
| Loading… | ||||
What this is
Fire code complaints received by the SF Fire Department geo-joined to this parcel. Includes complaint type, disposition, and outcome.
| Received | Description | Disposition Date | Disposition |
|---|---|---|---|
| Loading… | |||
What this is
SF 311 service requests geo-joined to this parcel. Includes maintenance complaints, street/sidewalk issues, and quality-of-life requests.
| Opened | Type | Agency | Category | Details | Status |
|---|---|---|---|---|---|
| Loading… | |||||
What this is
Buildings subject to SF's mandatory soft-story seismic retrofit program. Unreinforced multi-story wood-frame buildings must meet compliance tiers.
| Tier | Status |
|---|---|
| Loading… | |
What this is
Tenant buyout (Ellis Act pre-cursor) agreements recorded with the SF Rent Board. Tracks amounts paid to tenants to vacate rent-controlled units.
| Disclosure Date | Buyout Date | Amount | Tenants |
|---|---|---|---|
| Loading… | |||
Look up the next apartment before you sign
Search any SF address free — no account needed to see the risk rating.
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)
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)
Renter
For the weeks when the stakes are highest
$10/mo
Billed $120/year — save $24 vs monthly
- Unlimited basic reports
- 5 premium AI reports per month
- Download PDF & Excel reports
- Full public records (200 rows per dataset)
- Full event timeline — every year of history
- Landlord portfolio & ownership insights
Less than $0.34/day. Cancel anytime.
Cancel anytime · Data sourced from SF Open Data, DBI, SFFD, SF Rent Board & Planning