1845 Walnut St

Where 1845 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

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 761 ft of exterior wall, and across 19 residential floors the building carries 14,468 ft of it in total, divided among the 439 homes this screen estimates.

Its plate is compact at 0.75: 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 23.1 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.

Why 1845 Walnut St scores 38 out of 100

Daylight efficiency 45, Interior depth 11, 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 1968

Philadelphia records this building as going up in 1968, which puts it in the post-war stock.

As a rule, the period when plates got deep and facades became curtain wall: sealed glazing, lower floor-to-floor heights, and mechanical systems designed around a sealed box. Conversions here usually turn on whether the windows can be made to open and whether ceilings survive new plumbing. 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 63% daylight figure above deserves.

What the conversion would cost

$360 per square foot all-in across 659,840 sq ft of converted floor, or $237.5M in total — about $541K for each of the 439 homes.

That cost is charged across every converted square foot, including the 247,411 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 439 homes is $86.4M.

What would have to be true

A $151.2M gap before any grant, $141.2M after the modeled one. The smallest single change that would close it: average unit size 62% down.

The shortfall before any grant is $151.2M. Closing it from the value side means each of the 439 homes finishing at $541K rather than the $197K the model assumes — 175% 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 $518K a home. That is still above the $197K assumed, leaving $141.2M uncovered, which is why the grant does not unlock this one.

Nor do all four levers have to move. For 1845 Walnut St, one alone would close the gap at:

All four are sliders in the survey, where 1845 Walnut St re-scores against your own numbers.

How it compares in Center City Philadelphia

1845 Walnut St ranks 78th 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 25% of them at its deepest interior point. On size it is the 30th 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

46th of 65 zoned CMX5 — the comparison that shares its rules, rents and streets.

65 of the screened buildings are zoned CMX5. 1845 Walnut St ranks 46th 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 76 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: 22 S 17th St

The screened building closest to 1845 Walnut St in converted floor area is 22 S 17th St: 630,177 sq ft over 20 stories, against 659,840 sq ft over 20 here.

1845 Walnut St scores 38 to its 45, and with the size held roughly equal most of that shortfall comes from interior depth: 11 out of 100 here, 27 there (deepest interior point 69 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 800 ft apart.

Would it qualify for a RESIDE Act grant?

The model awards 1845 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 1845 Walnut St

The 4 closest the screen also covers, from 800 ft away. They are the colored outlines on the plan at the top of this page.

• 22 S 17th St
  20 stories · 65% daylit · 437 estimated homes · scores 45/100 (Marginal)
  about 800 ft away
• 1818 Market St
  40 stories · 62% daylit · 852 estimated homes · scores 35/100 (Marginal)
  about 840 ft away
• 1742 Market St
  14 stories · 100% daylit · 131 estimated homes · scores 92/100 (Strong candidate)
  about 900 ft away
• 1619 Walnut St
  6 stories · 100% daylit · 33 estimated homes · scores 82/100 (Strong candidate)
  about 900 ft away