Philadelphia multifamily underwriting operates differently from everywhere else in Pennsylvania, and differently from most other US markets. The Office of Property Assessment (OPA) reassesses annually like a Sun Belt market, not on the cycle-based system most other PA counties use. The Department of Licenses and Inspections (L&I) requires every rental unit to have a separate Rental License. The 10-year tax abatement program (now in modified form) shapes the new-construction landscape. Old housing stock means more lead, more lead disclosure obligations, and more deferred maintenance.
If you're buying multifamily in Philly, four things matter most.
Philadelphia OPA reassesses every year
Pennsylvania state law lets each county set its own reassessment cycle. Bucks, Chester, Montgomery, and most other PA counties have base years going back decades (Bucks: 1972; Chester: 1998; Montgomery: 1998). The assessed value is locked to that base year and the STEB Common-Level Ratio is used to compute the FMV-equivalent for appeals and statistics.
Philadelphia is the exception. OPA reassesses every year, and your purchase price becomes a primary input to next year's assessment. The post-sale tax bump that doesn't exist in Bucks or Chester DOES exist in Philly.
Combined millage in Philly is 1.4% of assessed value (roughly half goes to the city, half to the School District of Philadelphia). The math:
- Year 1 tax: current OPA assessed × 1.4%
- Year 2+ tax: OPA-reassessed value (likely catches up to purchase price) × 1.4%
For a $500K purchase where the current OPA assessed is $350K, the year-1 tax is around $4,900 (at current assessment) and the year-2 tax can be $7,000 (at re-assessed value). Full tax modeling guide.
The 10-year tax abatement: properties that received a tax abatement (on new construction, conversion, or major rehab) have their improvement value excluded from the tax bill for 10 years. Land value is taxed normally; building value is what's abated.
Reform via Bill 200366 (passed late 2019, effective for residential applications filed on or after January 1, 2022) phased down the residential abatement. The structure:
- Residential applications filed before January 1, 2022: full 100% abatement for the entire 10 years (grandfathered).
- Residential applications filed on or after January 1, 2022: phased structure. 100% abated in year 1, 90% in year 2, declining 10% per year, ending at 10% in year 10.
- Commercial (non-residential) applications: not affected by the reform. Still 100% abatement for 10 years.
- Conversion and rehabilitation abatements: separate program rules; check the specific abatement type filed for the property.
Practical implication: a property with an abatement from 2019 is more valuable to underwrite than one with a 2023 application, even at the same purchase price. Check OPA's parcel record for the abatement type and the filing year.
L&I rental licensing: every unit needs one
Philadelphia requires every rental unit to have a current Rental License from L&I. The license must be renewed annually. Properties without current licenses cannot legally collect rent, and the city has been increasingly aggressive about enforcement.
Before you bid, check whether the property has current Rental Licenses for each unit. The eCLIPSE portal shows license status. Missing or expired licenses are not just a clerical issue: they trigger inspection requirements, lead disclosure obligations, and in some cases certificate of rental suitability requirements before re-licensing.
A property where the prior owner let licenses lapse can be a substantial post-close project. Build the cost of re-licensing (inspections, repairs to pass, paperwork) into your offer.
Certificate of Rental Suitability and lead disclosure
For pre-1978 buildings (which is the vast majority of Philadelphia multifamily), federal lead-paint disclosure laws apply. Philly enforces additionally:
- Certificate of Rental Suitability is required when changing tenants or transferring ownership. It includes a lead-safe certification process for pre-1978 housing.
- Lead Safe Certification for properties with children under 6: requires lead-safe certification by a certified inspector.
- Lead disclosure to tenants at lease signing: mandatory federal-level disclosure that Philly enforces strictly.
The compliance is meaningful for older buildings. Plan for $500-$2,000 per unit on lead-safe certification work, plus ongoing inspection fees. Buildings with documented lead remediation pass through compliance more smoothly.
ROW certificate (Owner-Occupied or Investor)
The City requires a Right of Way certificate for any property change of ownership, including the sale of an investment property. This is a relatively routine filing but is something that needs to happen between contract and close. Most title companies handle it; just know it's part of the process.
L&I permits through eCLIPSE
eCLIPSE is the canonical source for Philly permits, licenses, and code violations. It's free to search without registering. Pull permit history, code violations, and rental license status for any property before bidding.
Cross-reference broker renovation claims against permit records. Philly has been aggressive about retroactive permit enforcement on visible work, and the city's L&I has authority to require retroactive permitting plus fines. See the full guide to checking permit history.
Older housing stock: the underwriting wildcards
Philadelphia's housing stock skews older than almost any major metro: 50%+ of single-family and multifamily housing was built before 1940. The underwriting implications:
- Knob-and-tube wiring: still in active service in many older buildings. Insurance carriers may require remediation. Costs $3,000-$15,000+ per unit to replace.
- Galvanized or lead plumbing supply lines: common in pre-1950 buildings. Replacement is recommended and sometimes mandatory.
- Asbestos: common in pre-1980 buildings (pipe insulation, floor tile, popcorn ceiling). Abatement during renovation triggers strict compliance.
- Lead paint: nearly universal in pre-1978 buildings. Disclosure and remediation requirements.
- Original wood-frame or brick rowhouse construction: durable but capex-intensive (roof, façade, party wall maintenance, basement waterproofing).
For value-add deals, plan capex generously. The all-in cost to bring a 1920s rowhouse triplex to modern rental standards is often $40,000-$100,000+ per unit when done properly.
Insurance considerations
Philadelphia insurance has hardened with the national trend but is materially cheaper than Florida or coastal Texas. Plan for $700-$1,400 per door per year on standard multifamily, more on buildings with knob-and-tube electrical or unaddressed deferred maintenance.
The standard checklist still applies
The Philadelphia-specific items above sit on top of the general pre-offer due diligence checklist. Permit history, code violations, demographics trajectory, debt service stress test, FEMA flood zone all still matter.
OPA annual reassessment, L&I rental license status, and the older housing stock are the dominant Philly-specific items. Get these right and the standard checklist takes care of the rest.
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