1524 Walnut St

Where 1524 Walnut St is

Its block in Center City Philadelphia, drawn from Philadelphia's own building outlines and street centerlines.

The plan: window line, shape and floor rhythm

38 ft of exterior wall for each home the screen estimates — enough for two- and three-bedroom homes across the plan.

The typical floor has 474 ft of exterior wall, and across 20 residential floors the building carries 9,473 ft of it in total, divided among the 249 homes this screen estimates.

Its plate is compact at 0.76: close to a square or a circle, the most efficient envelope an office can have and the least generous one for apartments: little perimeter to divide among homes. How window line and plate shape are measured.

At the model’s 750 sq ft average, the plan works out at about 12.4 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.

Why 1524 Walnut St scores 81 out of 100

Daylight efficiency 92, Interior depth 78, Scale 100, Finance 34 — each out of 100, then weighted.

Most of what it earns comes from daylight efficiency, and what holds it back most is finance, at 34 out of 100: remaining gap is 40% of conversion cost, scored from 60% down to 0%.

Built in 1928

Philadelphia records this building as going up in 1928, which puts it in the interwar stock.

As a rule, steel or concrete frames with punched windows and plates still narrow enough for daylight to reach the middle, often with high ceilings. Among the most convertible stock there is, and the reason so many early conversions were of buildings this age. That is the era’s general tendency rather than a finding about this building — the model reads an outline and a height, and can see nothing inside — but it is the first thing an architect would want to know, and it colours how much confidence the 86% daylight figure above deserves.

What the conversion would cost

$360 per square foot all-in across 271,959 sq ft of converted floor, or $97.9M in total — about $393K for each of the 249 homes.

That cost is charged across every converted square foot, including the 38,393 sq ft of windowless core, which has to be gutted, re-plumbed and sprinklered like the rest of the building and then earns nothing. Against it the model sets a completed value of $197K a home, which for 249 homes is $49.0M.

What would have to be true

A $48.9M gap before any grant, $38.9M after the modeled one. The smallest single change that would close it: average unit size 44% down.

The shortfall before any grant is $48.9M. Closing it from the value side means each of the 249 homes finishing at $393K rather than the $197K the model assumes — 100% more. Closing it from the cost side means getting all-in cost down from $360 to $180 per square foot.

A modeled RESIDE grant of $10.0M moves that threshold to $353K a home. That is still above the $197K assumed, leaving $38.9M uncovered, which is why the grant does not unlock this one.

Nor do all four levers have to move. For 1524 Walnut St, one alone would close the gap at:

All four are sliders in the survey, where 1524 Walnut St re-scores against your own numbers.

How it compares in Center City Philadelphia

1524 Walnut St ranks 34th of the 103 buildings screened here, against a median score of 67.

Its floor plate is better lit than 59% of them, and shallower than 62% of them at its deepest interior point. On size it is the 47th largest by estimated homes. The full survey of all 103 buildings ranks and maps every one of them, and the list by address links each to its own page.

Within the CMX5 zone

25th of 65 zoned CMX5 — the comparison that shares its rules, rents and streets.

65 of the screened buildings are zoned CMX5. 1524 Walnut St ranks 25th of them against a median score of 67. 28 score 70 or more, their median deepest interior point is 58 ft from a facade against this building’s 49 ft, and together they would hold an estimated 30,650 homes. The group’s top scorer is 112 N Broad St, at 93.

Its nearest match in size: 1800 John F Kennedy Blvd

The screened building closest to 1524 Walnut St in converted floor area is 1800 John F Kennedy Blvd: 265,987 sq ft over 20 stories, against 271,959 sq ft over 21 here.

1524 Walnut St scores 81 to its 92, and with the size held roughly equal most of that shortfall comes from interior depth: 78 out of 100 here, 100 there (deepest interior point 38 ft from a facade, scored from 80 ft down to 40 ft). On the money they sit in the same place: each falls short even with the modeled grant. The two stand about 1,800 ft apart.

Would it qualify for a RESIDE Act grant?

The model awards 1524 Walnut St $10.0M, on the assumption it qualifies. Whether it does, no published dataset can say.

That figure assumes the building meets the Act’s vacant-and-abandoned test, which turns on code-enforcement and receivership records no city publishes.

It does not sit in a 2018 designated Opportunity Zone, so it would not draw that Section 201 priority.

Other buildings screened near 1524 Walnut St

The 4 closest the screen also covers, from 230 ft away. They are the colored outlines on the plan at the top of this page.

• 1601 Walnut St
  15 stories · 95% daylit · 140 estimated homes · scores 92/100 (Strong candidate)
  about 230 ft away
• 1525 Locust St
  18 stories · 100% daylit · 121 estimated homes · scores 91/100 (Strong candidate)
  about 260 ft away
• 1500 Walnut St
  22 stories · 91% daylit · 537 estimated homes · scores 87/100 (Strong candidate)
  about 300 ft away
• 1619 Walnut St
  6 stories · 100% daylit · 33 estimated homes · scores 82/100 (Strong candidate)
  about 380 ft away