100 S Broad St

Where 100 S Broad 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

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

The typical floor has 1,031 ft of exterior wall, and across 21 residential floors the building carries 21,644 ft of it in total, divided among the 610 homes this screen estimates.

Its plate is elongated at 0.33: a slab or an L, which is why so much of the floor lies within reach of a window: the outline buys daylight that a square plan of the same area would not. How window line and plate shape are measured.

At the model’s 750 sq ft average, the plan works out at about 29.0 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.

Why 100 S Broad St scores 90 out of 100

Daylight efficiency 100, Interior depth 97, Scale 100, Finance 35 — each out of 100, then weighted.

Most of what it earns comes from daylight efficiency, and what holds it back most is finance, at 35 out of 100: remaining gap is 39% of conversion cost, scored from 60% down to 0%.

Built in 1898

Philadelphia records this building as going up in 1898, which puts it in the pre-1920 stock.

As a rule, the era that converts most readily: load-bearing masonry, small floor plates laid out before deep-plan offices were possible, operable windows and generous floor-to-floor heights. The usual obstacles are not daylight but hazardous materials, lifts and bringing structure up to current code. 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 97% daylight figure above deserves.

What the conversion would cost

$360 per square foot all-in across 592,747 sq ft of converted floor, or $213.4M in total — about $350K for each of the 610 homes.

That cost is charged across every converted square foot, including the 20,159 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 610 homes is $120.0M.

What would have to be true

A $93.4M gap before any grant, $83.4M after the modeled one. The smallest single change that would close it: average unit size 41% down.

The shortfall before any grant is $93.4M. Closing it from the value side means each of the 610 homes finishing at $350K rather than the $197K the model assumes — 78% more. Closing it from the cost side means getting all-in cost down from $360 to $202 per square foot.

A modeled RESIDE grant of $10.0M moves that threshold to $333K a home. That is still above the $197K assumed, leaving $83.4M uncovered, which is why the grant does not unlock this one.

Nor do all four levers have to move. For 100 S Broad St, one alone would close the gap at:

All four are sliders in the survey, where 100 S Broad St re-scores against your own numbers.

How it compares in Center City Philadelphia

100 S Broad St ranks 13th of the 100 buildings screened here, against a median score of 67.

Its floor plate is better lit than 77% of them, and shallower than 73% of them at its deepest interior point. On size it is the 18th largest by estimated homes. The full survey of all 100 buildings ranks and maps every one of them, and the list by address links each to its own page.

Within the CMX5 zone

13th of 63 zoned CMX5 — the comparison that shares its rules, rents and streets.

63 of the screened buildings are zoned CMX5. 100 S Broad St ranks 13th of them against a median score of 67. 28 score 70 or more, their median deepest interior point is 57 ft from a facade against this building’s 41 ft, and together they would hold an estimated 30,185 homes. The group’s top scorer is 112 N Broad St, at 93.

Its nearest match in size: 1500 Walnut St

The screened building closest to 100 S Broad St in converted floor area is 1500 Walnut St: 556,113 sq ft over 22 stories, against 592,747 sq ft over 22 here.

The two land within a few points of each other — 90 here, 87 there — so at this size the screen reads them as much the same prospect. On the money they sit in the same place: each falls short even with the modeled grant. The two stand about 700 ft apart.

Would it qualify for a RESIDE Act grant?

The model awards 100 S Broad 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 100 S Broad St

The 4 closest the screen also covers, from 240 ft away. They are the colored outlines on the plan at the top of this page.

• 115 S Broad St
  21 stories · 96% daylit · 180 estimated homes · scores 93/100 (Strong candidate)
  about 240 ft away
• 1 S Broad St
  26 stories · 86% daylit · 509 estimated homes · scores 81/100 (Strong candidate)
  about 340 ft away
• 1326 Chestnut St
  8 stories · 100% daylit · 76 estimated homes · scores 87/100 (Strong candidate)
  about 400 ft away
• 1327 Chestnut St
  18 stories · 63% daylit · 386 estimated homes · scores 39/100 (Marginal)
  about 430 ft away