1818 Market St

Where 1818 Market 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 726 ft of exterior wall, and across 39 residential floors the building carries 28,300 ft of it in total, divided among the 852 homes this screen estimates.

Its plate is compact at 0.79: 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 21.8 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.

Why 1818 Market St scores 35 out of 100

The weighted components add to 35, but the score is capped at 35 because its deepest interior point is 89 ft from a facade, past the 80 ft threshold beyond which conversion requires carving a light well.

Most of what it earns comes from daylight efficiency, and what holds it back most is interior depth, at 0 out of 100: deepest interior point 89 ft from a facade, scored from 80 ft down to 40 ft.

Built in 1976

Philadelphia records this building as going up in 1976, 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 62% daylight figure above deserves.

What the conversion would cost

$360 per square foot all-in across 1,283,267 sq ft of converted floor, or $462.0M in total — about $542K for each of the 852 homes.

That cost is charged across every converted square foot, including the 483,820 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 852 homes is $167.6M.

What would have to be true

A $294.4M gap before any grant, $284.4M after the modeled one. The smallest single change that would close it: average unit size 63% down.

The shortfall before any grant is $294.4M. Closing it from the value side means each of the 852 homes finishing at $542K rather than the $197K the model assumes — 176% more. Closing it from the cost side means getting all-in cost down from $360 to $131 per square foot.

A modeled RESIDE grant of $10.0M moves that threshold to $530K a home. That is still above the $197K assumed, leaving $284.4M uncovered, which is why the grant does not unlock this one.

Nor do all four levers have to move. For 1818 Market St, one alone would close the gap at:

All four are sliders in the survey, where 1818 Market St re-scores against your own numbers.

How it compares in Center City Philadelphia

1818 Market St ranks 82nd of the 103 buildings screened here, against a median score of 67.

Its floor plate is better lit than 17% of them, and shallower than 11% of them at its deepest interior point. On size it is the 11th 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

50th of 65 zoned CMX5 — the comparison that shares its rules, rents and streets.

65 of the screened buildings are zoned CMX5. 1818 Market St ranks 50th 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 89 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: 1901 Market St

The screened building closest to 1818 Market St in converted floor area is 1901 Market St: 1,357,416 sq ft over 45 stories, against 1,283,267 sq ft over 40 here.

The two land within a few points of each other — 35 here, 35 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 400 ft apart.

Would it qualify for a RESIDE Act grant?

The model awards 1818 Market 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 1818 Market St

The 4 closest the screen also covers, from 270 ft away. They are the colored outlines on the plan at the top of this page.

• 1835 Market St
  29 stories · 63% daylit · 565 estimated homes · scores 36/100 (Marginal)
  about 270 ft away
• 1801 Market St
  27 stories · 66% daylit · 527 estimated homes · scores 40/100 (Marginal)
  about 300 ft away
• 1742 Market St
  14 stories · 100% daylit · 131 estimated homes · scores 92/100 (Strong candidate)
  about 320 ft away
• 1901 Market St
  45 stories · 70% daylit · 1,009 estimated homes · scores 35/100 (Marginal)
  about 400 ft away