The Block Report

Mixed-use report

509 S 4th St

3 stories · 1,992 sqft · RM1 · built 1920

Owner-occupied · assessed $428K · sold 1×. On the 500 block of S 4th St.

Street view of 509 S 4th St
From the street — imagery © Google
From above — imagery © Esri, Maxar

Property summary

Assessment$428KCity assessed value Last sale$210KRecorded 2001 Est. annual tax$5K/yearAssessment × 1.3998% Tax delinquency—Snapshot unavailable Permits0Shown in this report ViolationsNone openNo open L&I cases

What stands out

From the public record

What the record is signaling

Early patterns mined across this property's dated public records. Each flag shows what triggered it and where the inference stops.

watch signalAssessment/permit mismatch

The assessment jumped 40% in 2023, but no matching permit appears in the property timeline.

Evidence: assessment moved from $342,100 to $479,300 · no permit shown in 2022-2024

Limit: Not proof of unpermitted work; reassessment, corrected data, or a permit under another parcel can also explain it.

Transparent record rules, not a machine-learning forecast. A signal is a prompt to verify the cited record, not a prediction or allegation.

What to do with this

The record, translated into moves — what a buyer, the owner, and a landlord would each want to check next under Philadelphia's actual rules.

If you’re buying

Built 1920: lead rules apply

Federal law requires a lead-paint disclosure at sale for any pre-1978 home. If it will be rented, Philadelphia also requires a lead-safe or lead-free certificate before a rental license can issue.

The last transfer was not a sale

The most recent recorded deed moved for nominal consideration, within one family. That is where tangled-title problems live — budget a real title search. (Occupants untangling an inherited deed can get help from the city's Tangled Title Fund.)

If you’re the landlord

Lead certificate is not optional

Built 1920: every rental unit needs a lead-safe or lead-free certificate on file with the City. Without one: fines up to $2,000/day per unit, tenants may withhold rent, courts can order rent refunded — and no eviction will stand.

Licensed rental — keep it that way

Renewal requires city tax clearance and zero open L&I violations on the property. A lapsed license suspends the right to collect rent or evict.

Derived from this house's public records and the city's rules as of 2026 (abatement ordinance, Homestead, rental licensing, lead certification, L&I process, excavation protections). Informational only — not legal, tax, or investment advice.

The investment read

How this building has moved and where it's pointed: the city's assessed value (not a listing price) over 12 years, charted against its block; appreciation is that history's pace, and the 5-year figure simply extends it. Yield estimates rent-vs-price from area rents. Ask the record to dig into any number.

Assessed value
$428K
built 1920
Price / sq ft
$215
block $236 · below block
Appreciation
+23%
+2%/yr, city 6.5%
In 5 years (~2031)
~$429K
+2%/yr own pace held 5 yrs — extrapolation, not a forecast
Est. tax / yr
$5K
1.07% effective
Jun 2022 tax snapshot
—
Gross yield
6.9%
≈$2K/mo rent
Times sold
1
kept in the family

Value vs. the block, over time — sales, permits & L&I events marked on the line

$0$500K$1.0MBefore this chart — 2001: Sold $210K 2008: 6 L&I violations 2008: L&I: 1 failed, 1 passed$428K201620222027
This houseBlock median & rangePermit

The paper trail

History

sold $210K (2001); 6 L&I violations (2008); L&I: 1 failed, 1 passed (2008).

  1. 2001 $210KSold
  2. 2008 6 L&I violationsL&IL&I: 1 failed, 1 passedL&I visit

Flags: active rental license · long-held within one family. Informational only — not investment advice or a consumer report (FCRA).

The house, on paper

The city assessor's field record — the physical spec sheet behind the assessed number.

Stories
3
Interior
1,992 sqft
livable area
Lot
875 sqft
Exterior condition
Average
city code 4
Interior condition
Average
city code 4
Quality grade
C
assessor's grade
Zoning
RM1
city zoning code

OPA field-assessment attributes. Condition and grade are the assessor's codes, not an inspection.

Run the numbers

What owning 509 S 4th St takes, at your price and your rate. Taxes start with an annual estimate from the City’s taxable assessment, not a current bill or balance; rent starts at the area median. Assessed value is not an asking price — set the price slider to the real one.

$428K
20%
6.875%
$2K/mo
Mortgage
—
P&I · 30-yr fixed
All-in monthly
—
+ taxes & insurance
Cash to close
—
down + ~4% costs
Cash flow
—
rent − all costs · /mo
Cap rate
—
NOI ÷ price
Cash-on-cash
—
year-1 return on cash in

Estimates for orientation, not advice. Assumes a 30-year fixed loan, $1,400/yr insurance, 1% of price/yr maintenance; taxes from this parcel's record.

Block context

509 S 4th St sits on the 500 block of S 4th St. Open the block report to compare its parcels, ownership and public-record history.

See the whole block →

Next door: 507 S 4th St  ·  511 S 4th St

Where this comes from

Methodology & freshness

Available City datasets are queried from OpenDataPhilly (phl.carto.com), then reports are cached and refreshed on a rolling schedule. Source dates vary: the parcel-level tax-delinquency snapshot is June 2022 and the separate detailed tax ledger ends in 2016, so neither establishes today’s balance. Other dossiers re-pull on view once stale, and citywide benchmarks recompute weekly. AI-written passages are generated from these records only and rejected if they state a number the record doesn't hold.

Official city record ↗  ·  L&I history ↗  ·  See the whole block  ·  Download this record (JSON)