House report
623 Mountain St
3 bd · 1 ba · 2 stories · 810 sqft · RSA5 · built 1920
Owner-occupied · assessed $248K · sold 2×. On the 600 block of Mountain St.
Reading this house's deeds, permits and assessments…
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
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.
Single-family rowhouse (the classic Philly row). Converting to a duplex or apartments needs a use variance the zoning board rarely grants — Pennsylvania courts require a physical hardship of the lot itself, and economics alone do not qualify.
If you own it
This home reads owner-occupied but shows no Homestead Exemption, which removes $100,000 from the taxable assessment (worth up to $1,399/yr). Applying through the City is free and takes minutes.
Interest and penalties keep compounding until a Revenue payment agreement is in place, and a lien is already filed — an owner-occupant agreement also stops the sheriff-sale track.
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 house 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 analyst below to dig into any number.
Value vs. the block, over time — sales, permits & L&I events marked on the line
Bought for $25K in 1999. Owner pulled a plumbing permit in 2013.
- 1999 $25KSold
- 2007 L&I violationL&I
- 2008 L&I violationL&I
- 2010 10 L&I violationsL&I$300KSold
- 2013 PlumbingPermit
Flags: $2K back taxes (2015–2016, $50 of it interest & penalties, lien filed). 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.
OPA field-assessment attributes. Condition and grade are the assessor's codes, not an inspection.
Run the numbers
What owning 623 Mountain St takes, at your price and your rate. Taxes are this house's actual bill from the city record; rent starts at the area median. Assessed value is not an asking price — set the price slider to the real one.
When this house last sold (2010) a 30-year mortgage ran about 4.69% — Freddie Mac's average that year.
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.
Next door: 621 Mountain St · 625 Mountain St
Where this comes from
- Assessment, spec sheet & owner — OPA Property Assessments, Office of Property Assessment
- Sales & deed history — Realty Transfer Tax records, Recorder of Deeds
- Permits, violations & inspections — L&I Property History · Atlas
- Back taxes & liens — Real Estate Tax Balances, Dept. of Revenue
- Zoning appeals — L&I & Zoning Board appeals
- Neighborhood income & rents — US Census ACS 5-year estimates
- Historical mortgage rates — Freddie Mac Primary Mortgage Market Survey, annual averages
- Imagery — Street photo © Google · Aerial © Esri, Maxar
City datasets are fetched live from OpenDataPhilly (phl.carto.com) and cached briefly. AI-written passages are generated from these records only and rejected if they state a number the record doesn't hold.
First time here?
This is 623 Mountain St,
on paper.
Built 1920. Every deed, permit, L&I visit, tax bill and sale for this house — plus its whole block.
No signup, no teaser
The whole record is free.
Who owns what, what they paid, what they built, what they owe. Scroll and it's all here — the paid part is not the data.
Three taps, you're oriented
What to catch on the way down.
On the way down: the story of the house, its paper trail drawn on the value chart, and run-the-numbers, a calculator seeded with this house's actual tax bill.
Official city record ↗ · L&I history ↗ · See the whole block · Download this record (JSON)