100 N 18th St

Where 100 N 18th 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

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

The typical floor has 799 ft of exterior wall, and across 33 residential floors the building carries 26,381 ft of it in total, divided among the 803 homes this screen estimates.

Its plate is moderately compact at 0.69: a squarish plan, with enough perimeter for a conventional double-loaded corridor. How window line and plate shape are measured.

At the model’s 750 sq ft average, the plan works out at about 24.3 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.

Why 100 N 18th St scores 48 out of 100

Daylight efficiency 51, Interior depth 38, Scale 100, Finance 1 — each out of 100, then weighted.

Most of what it earns comes from daylight efficiency, and what holds it back most is finance, at 1 out of 100: remaining gap is 59% of conversion cost, scored from 60% down to 0%.

Built in 1985

Philadelphia records this building as going up in 1985, which puts it in the late-modern stock.

As a rule, typically the hardest to convert: the deepest plates of any era, large central cores, and floor-to-floor heights tight enough that running residential drainage under a ceiling can be the thing that ends a project. 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 65% daylight figure above deserves.

What the conversion would cost

$360 per square foot all-in across 1,150,615 sq ft of converted floor, or $414.2M in total — about $516K for each of the 803 homes.

That cost is charged across every converted square foot, including the 396,996 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 803 homes is $158.0M.

What would have to be true

A $256.3M gap before any grant, $246.3M after the modeled one. The smallest single change that would close it: average unit size 61% down.

The shortfall before any grant is $256.3M. Closing it from the value side means each of the 803 homes finishing at $516K rather than the $197K the model assumes — 162% more. Closing it from the cost side means getting all-in cost down from $360 to $137 per square foot.

A modeled RESIDE grant of $10.0M moves that threshold to $503K a home. That is still above the $197K assumed, leaving $246.3M uncovered, which is why the grant does not unlock this one.

Nor do all four levers have to move. For 100 N 18th St, one alone would close the gap at:

All four are sliders in the survey, where 100 N 18th St re-scores against your own numbers.

How it compares in Center City Philadelphia

100 N 18th St ranks 68th of the 103 buildings screened here, against a median score of 67.

Its floor plate is better lit than 25% of them, and shallower than 37% of them at its deepest interior point. On size it is the 13th 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

41st of 65 zoned CMX5 — the comparison that shares its rules, rents and streets.

65 of the screened buildings are zoned CMX5. 100 N 18th St ranks 41st 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 65 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: 1101 Market St

The screened building closest to 100 N 18th St in converted floor area is 1101 Market St: 1,192,353 sq ft over 32 stories, against 1,150,615 sq ft over 34 here.

The two land within a few points of each other — 48 here, 50 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 3,400 ft apart.

Would it qualify for a RESIDE Act grant?

The model awards 100 N 18th 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 N 18th 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.

• 1717 Arch St
  51 stories · 67% daylit · 1,072 estimated homes · scores 47/100 (Marginal)
  about 240 ft away
• 130 N 18th St
  30 stories · 85% daylit · 691 estimated homes · scores 80/100 (Strong candidate)
  about 290 ft away
• 1701 John F Kennedy Blvd
  58 stories · 64% daylit · 1,885 estimated homes · scores 35/100 (Marginal)
  about 490 ft away
• 1800 John F Kennedy Blvd
  20 stories · 98% daylit · 278 estimated homes · scores 92/100 (Strong candidate)
  about 630 ft away