Office-to-Housing Conversion in Center City Philadelphia

Of 103 office-linked buildings at least 60 feet tall in Center City Philadelphia, none pencil for residential conversion, with or without a grant from the RESIDE Act, at default assumptions.

PA-2 & PA-3 · Center City Philadelphia, Pennsylvania · Screened from City of Philadelphia open GIS data · Last updated 2026-09-15 · Cite or download the data

Buildings screened

103

≥ 60 ft, office use on the tax roll

Pencil unsubsidized

no grant required

Unlocked by RESIDE

at default assumptions

Worth a study

suitability score ≥ 50

Median gap per home

$175K

score ≥ 50, not already pencilling

Never pencil

103

at default assumptions

Loading building data…

Every assumption in the model is a slider. Change conversion cost, unit size, circulation efficiency or completed value in the Assumptions tab and all 103 buildings re-score and re-rank live. The full analysis continues below.

The gap here is wider than the grant

Center City’s floor plates are workable. What separates Philadelphia from the other two study areas is not geometry but the size of the hole between what a conversion costs and what the finished apartment is worth.

66 of the 103 buildings screened here score at least 50, meaning the model rates them worth a professional feasibility study. The median building has 80% of its floor area within daylight reach and a deepest interior point 57 feet from a window, and 21 are past the 80-foot threshold where conversion needs a carved light well. That is ordinary: better than Downtown San José, not as good as Greater Downtown Denver.

Of 103 office-linked buildings at least 60 feet tall, 0 pencil for conversion unsubsidized and 0 are unlocked by a modeled RESIDE grant. Across the 66 that score at least 50 and do not already pencil, the median financing gap is $175K per home, against a modeled award capped at $60K per home. The grant covers roughly 34% of the gap.

That gap is the widest of the three study areas, and the reason is what a completed home is worth. This model values a converted apartment at $197K, the median price per apartment unit sold across Philadelphia in the first half of 2026 — the lowest of the three cities. Against a conversion cost the model puts at $360 per square foot, charged on the whole floor while only the daylit band earns revenue, the arithmetic does not close.

One thing here is firmer than on the other two pages. Philadelphia records a storey count for every property on its tax roll, so the floor counts behind these numbers are the city’s own rather than a building’s height divided by a nominal floor-to-floor. That matters: the usual estimate is off by roughly a quarter per building in Center City, and Comcast Center alone would come out 81 storeys tall instead of its actual 58. The same records are also the reason 265 buildings that cleared the height and use screens are absent from this page: for those, the city’s own accounts disagree about how many storeys the building has, and this survey withholds them rather than picking one.

Why floor plates decide which buildings are worth studying

Floor-plate geometry decides whether an office floor can hold apartments at all. In Center City Philadelphia most screened buildings clear that bar; what stops them is cost, covered below.

2000 MARKET ST — 66% of each floor sits within daylight reach of a facade. The hatched area is windowless core: 10,007 sq ft per floor that must be renovated but can never be rented as an apartment. Deepest interior point: 74 ft from the nearest window.

Building codes limit how far a habitable room can sit from a window — roughly 25 to 35 feet. This model erodes each real building footprint inward by 35 feet, the generous end of that range. What survives the erosion is windowless dead core. What remains is the daylit band where apartments can legally go.

Across the 103 buildings screened here, the median has 80% of its floor area within daylight reach and a deepest interior point 57 feet from the nearest window. 21 of them are past the 80-foot threshold where conversion requires carving a light well through the building — at which point it effectively never pencils.

Conversion cost is charged on gross floor area while revenue is earned only on the daylit band. That is not an accounting trick — it is the real economics. You must gut, re-plumb and sprinkler the windowless core, but you can never rent an apartment in it. Deep floor plates are penalized twice, which is precisely why they fail in practice.

This is why a subsidy program alone does not produce conversions, and why a list of vacant buildings is not a pipeline. Information was never the bottleneck — cities have published vacancy reports for years. The bottleneck is that establishing which specific buildings are physically convertible is expensive expert work.

Why no building in Center City Philadelphia is unlocked by the RESIDE Act

A building is unlocked when it fails on financing alone and the modeled grant closes the difference. At default assumptions, no building screened here that does not already pencil has a gap small enough.

Of the 103 buildings screened, 66 have a conversion suitability score of at least 50 and do not pencil on their own. Across those buildings the median financing gap before any subsidy is $175K per home, while the modeled RESIDE award is capped at $60K per home. The grant covers part of the gap; it does not close it.

Profiled in detail — the highest-scoring buildings in the survey: 112 N BROAD ST, 115 S BROAD ST, 230 S BROAD ST, 1313 WALNUT ST, 1420 WALNUT ST, 1742 MARKET ST, 1880 JOHN F KENNEDY BLVD, 1601 WALNUT ST, 1800 JOHN F KENNEDY BLVD, 1211 CHESTNUT ST, 736 ARCH ST, 1525 LOCUST ST, 100 S BROAD ST, 1628 JOHN F KENNEDY BLVD, 30 S 15TH ST, 1500 WALNUT ST, 1326 CHESTNUT ST, 213 S BROAD ST, 448 N 10TH ST, 461 N 3RD ST, 901 ARCH ST, 117 N 8TH ST, 1207 CHESTNUT ST, 1033 N 2ND ST and 232 MARKET ST.

All 103 screened buildings are in the survey above, where the completed-value and cost sliders show what would have to change.

What Philadelphia is already doing

Two Center City conversions are under way without any federal conversion grant. PMC Property Group and Dean Adler bought Centre Square at 1500 Market Street for about $94 million, with plans for 250 to 500 apartments, and PMC is converting ten floors of Ten Penn Center at 1801 Market Street into 273 apartments. Both are in the stock this page screens.

That is the most useful fact on this page, and it cuts against the model. If nothing in Center City pencils, the developers converting two of its largest office buildings have not noticed. The likeliest explanation is the completed value: $197K is a city-wide median across trades that skew to smaller, older, lower-basis assets, and a converted apartment on Market Street is not that asset. The survey below lets you raise it and watch the answer change.

Center City’s office vacancy rate was 20% in the Center City District’s State of Center City 2026 report — lower than many peer downtowns and lower than most of Philadelphia’s own suburbs. Vacancy here is a weaker argument for conversion than it is in Denver or San José, and 103 buildings being screened does not mean 103 buildings are empty.

Center City spans two congressional districts almost evenly. Pennsylvania's 3rd District, represented by Dwight Evans since 2019, takes in 53 of the buildings screened here, and the 2nd District, represented by Brendan Boyle, takes in 50. Clipping the study area to one district would divide Center City along a line with no analytical meaning, so both are reported. Evans is not seeking reelection in 2026 and Chris Rabb won the Democratic primary to succeed him on May 19, 2026, so the 3rd District's member of Congress is likely to change in January 2027.

What the RESIDE Act, Section 210 of the ROAD to Housing Act, funds

The RESIDE Act is law, but it has no money yet, its grants go to cities rather than developers, and only vacant and abandoned buildings qualify. All three facts are widely misreported.

The Revitalizing Empty Structures Into Desirable Environments Act was introduced as H.R. 5591 in the 119th Congress and enacted as Section 210 of the 21st Century ROAD to Housing Act, which became law without the President’s signature on July 11, 2026. It authorizes HUD to run a pilot program, in fiscal years 2027 through 2031, of competitive grants to convert vacant and abandoned buildings into attainable housing, with priority for economically distressed communities, Opportunity Zones, needs in a city’s consolidated plan, and cities that have passed ordinances easing conversion.

The program has no money yet. The law authorizes it only “subject to the availability of funds appropriated,” and as of September 9, 2026, Congress had appropriated nothing. In a year Congress provides at least $100 million, each grant is $1 million to $10 million; with less, HUD must spread the money across as many grants as it can. The widely quoted $100 million a year from HOME funding above $1.35 billion comes from the introduced bill, not the law.

Most empty offices would not qualify. The law covers only a vacant and abandoned building: one built for commercial or industrial use that code enforcement has found unsafe, with no corrective action 90 days after the owner was notified, or that is in court-ordered receivership or nuisance abatement, or is abandoned under state law. This survey cannot see code enforcement or court records, so a building shown as unlocked by RESIDE here is one that would pencil with a modeled grant if it qualified. The homes must also be attainable, serving households up to 120% of area median income with most units affordable at 60%, while this model values every home at market completed value, so its grant results are optimistic.

Individual awards are capped at $10.0M, and eligible applicants are HOME participating jurisdictions — states and local governments — not private developers or building owners. That changes what this tool is for. It is not a developer’s capital stack; it is a worksheet for the grant application a city would file, and for the question of which buildings would justify the ask.

Because HUD has not published a Notice of Funding Opportunity, the award formula used here — 30% of eligible conversion cost, capped at $60K per home and $10.0M per award — is modeled on how comparable HUD gap-financing programs are structured. The $10.0M per-award cap is statutory. The rest is an assumption, and 57 of the 103 buildings here hit that statutory ceiling.

More on the law: The ROAD to Housing Act explained · Environmental review changes · CDBG and HOME changes · Opportunity Zones

How this was computed, and what it cannot tell you

Every figure on this page is reproducible from public data. Stating the limits is part of the method, not a disclaimer attached to it.

Building footprints, LiDAR-derived heights, addresses and zoning come from the City of Philadelphia’s open data services, and use type and floor counts from the Office of Property Assessment. Footprints are projected to a local tangent plane in feet, eroded inward by 35 feet to separate daylit band from dead core, and the largest circle that fits inside each footprint gives the distance from the deepest interior point to the nearest facade. Unit yield is the daylit band times a 80% circulation factor divided by a 750 sq ft average home, across every floor above the ground floor. Cost is a base of $260/sq ft plus itemized change-of-occupancy triggers — plumbing risers, operable windows, egress stairs, sprinklers — weighed against completed value, then against the modeled grant.

For Center City Philadelphia the model replaces 2 defaults with local figures. Completed value per home is $197K: the median price per apartment unit sold across Philadelphia in the first half of 2026 (Northmarq, 2026-09-15). The seismic retrofit allowance is $0 per sq ft: Philadelphia's existing-building code requires a seismic upgrade on a change of occupancy only when the building moves to a higher risk category, and office and apartment buildings are both Risk Category II (UpCodes, 2026-09-15).

The geometry math is validated against shapes with known analytic answers, and computed floor areas agree with the city’s own recorded areas to within 0.01%, which confirms the coordinate projection. The browser model that powers the interactive survey above is checked against the Python engine on every build; both must agree on units, cost, grant, gap, tier and score for all 103 buildings.

What this tool does not know

It screens geometry from footprints. It cannot see interior cores, columns, ceiling heights, post-tension slabs or mechanical systems.
It does not know which buildings are vacant. Center City’s office vacancy rate was 20% in 2026; this screen does not assert that any specific building is empty.
Story count is derived from LiDAR height ÷ floor-to-floor, not read from plans.
It does not model the statute’s four priorities — economically distressed communities, Opportunity Zones, needs in the city’s consolidated plan and local ordinances that ease conversion — or Philadelphia’s own tax abatements for conversion.
It cannot tell whether a building would qualify for a RESIDE grant, which requires a code-enforcement finding, receivership or abandonment, and it values every home at market rate although RESIDE-funded housing must be mostly affordable.
HUD has not published an award formula, so every per-project grant here is modeled rather than known.
A high score means worth a professional feasibility study — never “convertible.”
Completed value per home is a Philadelphia-wide median across multifamily trades that the source attributes to smaller, older, lower-basis assets. It is almost certainly low for a Center City conversion, and it is the single assumption this page’s finding rests on. Two Center City conversions are under way while this model says none pencils; that disagreement is the input’s, not the geometry’s.
Parking levels are not modeled. Several buildings here carry a parking-garage account on the tax roll, and the model excludes only the ground floor, so their home counts are upper bounds. A higher home count only improves the economics, so this makes the finding that nothing pencils more conservative, not less.
265 buildings are withheld because Philadelphia’s own records disagree about how many storeys they have, not because they failed the screen. They are excluded rather than published with a guessed floor count.
Party walls are treated as facade. The geometry model treats every footprint edge as exposed, so Center City’s attached stock looks more favourable than it is.

Questions

Can empty office buildings in Center City Philadelphia be converted into housing?

Of 103 office-linked buildings at least 60 feet tall in Center City, this model rates 66 at least worth a professional feasibility study. But at default assumptions none pencils, with or without a RESIDE Act grant. The binding constraint in Philadelphia is money, not the shape of the floor: across the 66 buildings that score at least 50 and do not already pencil, the median financing gap is $175K per home, while the modeled grant is capped at $60K per home.

Why do most office-to-residential conversions fail?

Usually floor-plate geometry. Apartments need light and air, and building codes limit how far a habitable room can sit from a window — roughly 25 to 35 feet. Office floors were built deep on purpose, so the middle of the plate is windowless core that can never legally become a bedroom. In this survey the median building has 80% of its floor area within daylight reach and a deepest interior point 57 feet from the nearest window. 21 of the 103 buildings are past the 80-foot threshold where conversion requires carving a light well, at which point it effectively never pencils. In Center City Philadelphia, though, most floor plates clear that bar; the gap between conversion cost and completed value is what keeps them from penciling.

Why does this page screen fewer buildings than there are office towers in Center City?

Because it only publishes buildings whose floor count it can source. Philadelphia records a storey count for every property on the tax roll, and this survey uses that figure rather than dividing height by a nominal floor-to-floor, which is wrong by roughly 25% per building here. Where a building's records disagree with each other — the Wanamaker Building's accounts report one, three and seven storeys — it is withheld. That removes 265 buildings that otherwise passed the height and use screens. Buildings already converted to apartments are also excluded, since they are not prospective office stock.

What is the RESIDE Act and is it law?

Yes, it is law. The RESIDE Act — Revitalizing Empty Structures Into Desirable Environments — was introduced as H.R. 5591 and enacted as Section 210 of the 21st Century ROAD to Housing Act (Public Law 119-101), which became law without the President's signature on July 11, 2026. It authorizes HUD to run a pilot program, in fiscal years 2027 through 2031, of competitive grants to states and local governments to convert vacant and abandoned commercial and industrial buildings into attainable housing.

Which buildings qualify for a RESIDE Act grant?

Far fewer than "empty offices" suggests. The law covers only a vacant and abandoned building: one built as a warehouse, factory, mall, strip mall or hotel, or for another commercial or industrial use such as offices, that code enforcement has found unsafe, with no corrective action 90 days after the owner was notified, or that is in court-ordered receivership or nuisance abatement, or is abandoned under state law. A building that is merely empty does not qualify. The homes it creates must be attainable housing, serving households earning up to 120% of area median income, with most units affordable at 60%.

What does the ROAD to Housing Act mean for office conversions in Center City Philadelphia?

Several parts of the 21st Century ROAD to Housing Act apply. The RESIDE Act (Section 210) would fund conversions of vacant and abandoned buildings, if Congress appropriates money and a building meets that test. Section 206 gives HUD-funded conversions of existing office buildings a lighter environmental review once HUD writes its rules. Section 204 lets a city spend up to 20% of its Community Development Block Grant on new affordable housing construction. Section 201 lets HUD favor housing grants in Opportunity Zones, and 11 of the 103 buildings screened here sit in a 2018 Opportunity Zone tract.

How much money does the RESIDE Act actually provide?

None yet. The law authorizes the pilot only "subject to the availability of funds appropriated," authorizes no new funding, and as of September 9, 2026, Congress had appropriated nothing for it. In a year Congress provides at least $100 million, each grant is between $1 million and $10 million; with less, HUD must spread the money across as many grants as it can. The often quoted $100 million a year from HOME funding above $1.35 billion comes from the introduced bill and is not in the law.

Who applies for a RESIDE Act grant — the developer or the city?

The city. Eligible applicants are HOME participating jurisdictions — states and local governments — not private developers or building owners. That makes this tool a municipal grant-application worksheet rather than a developer's pro-forma: it estimates what Philadelphia could credibly ask HUD for, and which buildings would justify the ask.

If nothing pencils, why is PMC converting Centre Square and Ten Penn Center?

Because the completed value this model uses is probably too low for Center City. It values a converted home at $197K, the median price per apartment unit sold across all of Philadelphia in the first half of 2026, on sales the source attributes to smaller, older, lower-basis assets. That is the same metric the Denver page uses, which is why it was chosen, but a converted apartment on Market Street is not the asset it describes. The survey on this page has a completed-value slider; raising it is the honest way to see what the model would say with a Center City comparable.

Does this tool know which Philadelphia buildings are actually vacant?

No. Center City's office vacancy rate was 20% in the Center City District's State of Center City 2026 report, but this screen does not assert that any specific building is empty. Ownership, lease status and tenancy are outside what public footprint, zoning and assessment data can show — and the RESIDE Act's vacant-and-abandoned test is a legal finding, not a data lookup.

How accurate is this analysis?

It is a screen, not a feasibility study. The geometry is computed from real city footprints and LiDAR-derived heights, and the floor-plate math is validated against shapes with known analytic answers; computed floor areas agree with the city's own recorded areas to within 0.01%. But the model cannot see interior columns, existing cores, ceiling heights, post-tension slabs, or mechanical systems, though story counts here are the Philadelphia Office of Property Assessment's own figures rather than a number inferred from height. A high score means a building is worth a professional feasibility study — never that it is convertible.

Cite or reuse this analysis

Everything on this page is free to quote, republish and build on, with credit. The scored dataset behind it is one download.

Suggested citation

RESIDE Act Feasibility Engine, “Office-to-Housing Conversion in Center City Philadelphia,” resideact.org/philadelphia, updated 2026-09-15.

Download the scored dataset (GeoJSON)Read the method

The text and dataset are licensed under CC BY 4.0: copy, adapt and republish them, commercially or not, with credit and a link back. Footprints, heights and zoning come from the City of Philadelphia, whose own terms still apply to that source data. See the terms of use.

Sources

Center City Philadelphia's office vacancy rate was 20% in the Center City District's State of Center City 2026 report, lower than many peer downtowns and most of Philadelphia's suburbs. Center City District, reported by The Philadelphia Inquirer, “Remote work still stings, but Center City remains a jobs hub and popular neighborhood, report finds” — verified 2026-09-15.
Two Center City office-to-residential conversions are under way: PMC Property Group and Dean Adler bought Centre Square at 1500 Market Street for about $94M to build 250 to 500 apartments, and PMC is converting ten floors of Ten Penn Center at 1801 Market Street into 273 apartments. Bisnow, “Center City's Largest Office Space Slated For Resi Conversion: The Philadelphia Deal Sheet” — verified 2026-09-15.
The median price per apartment unit sold across Philadelphia in the first half of 2026 was roughly $196,700, on sales Northmarq attributes to smaller, older, lower-basis assets. Northmarq, “Philadelphia multifamily market: rent growth builds during first half, Q2 2026” — verified 2026-09-15.
The RESIDE Act is Section 210 of the 21st Century ROAD to Housing Act (Public Law 119-101), which became law without the President's signature on July 11, 2026. Section 210 authorizes a HUD pilot program, in fiscal years 2027 through 2031 and subject to appropriations, of competitive grants to HOME participating jurisdictions to convert vacant and abandoned buildings into attainable housing; in a year at least $100M is available, each grant is $1M to $10M. U.S. Government Publishing Office, “Public Law 119-101, 21st Century ROAD to Housing Act” — verified 2026-09-14.
As of September 9, 2026, HUD had issued no Notice of Funding Opportunity, guidance or rule for the RESIDE pilot, and no funds had been appropriated for it. Bipartisan Policy Center, “21st Century ROAD to Housing Act Implementation Tracker” — verified 2026-09-14.
The RESIDE Act was introduced as H.R. 5591 in the 119th Congress. As introduced, it would have funded the program with up to $100M a year of HOME appropriations above $1.35B; the enacted law does not. Congress.gov, “H.R.5591 — RESIDE Act” — verified 2026-09-14.
Of the 103 buildings screened in Center City Philadelphia, 53 lie in Pennsylvania's 3rd Congressional District and 50 in the 2nd, checked building by building against the 119th Congress district boundaries, which are identical to the 120th Congress boundaries for these districts. U.S. Census Bureau, “TIGERweb Legislative Map Service: 120th Congressional Districts” — verified 2026-09-15.
Building footprints with heights, address points, zoning and planning district boundaries come from the City of Philadelphia's open data services, and property use, floor counts and year built from the Office of Property Assessment. City of Philadelphia, “OpenDataPhilly: Building Footprints, Address Points, Zoning, Planning Districts, OPA Properties” — verified 2026-09-15.
Completed value per home is $197K: the median price per apartment unit sold across Philadelphia in the first half of 2026. Northmarq, “Philadelphia multifamily market: rent growth builds during first half, Q2 2026” — verified 2026-09-15.
The seismic retrofit allowance is $0 per sq ft: Philadelphia's existing-building code requires a seismic upgrade on a change of occupancy only when the building moves to a higher risk category, and office and apartment buildings are both Risk Category II. UpCodes, “Philadelphia Existing Building Code 2018, Chapter 10, Section 1006.3” — verified 2026-09-15.

The scored dataset behind this page is available as GeoJSON. Findings generated 2026-09-15 from City of Philadelphia open data (Building Footprints, Address Points, Zoning, Planning Districts; OPA property assessments).