1435 Walnut St

Where 1435 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

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

The typical floor has 347 ft of exterior wall, and across 5 residential floors the building carries 1,735 ft of it in total, divided among the 38 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 7.6 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.

Why 1435 Walnut St scores 82 out of 100

Daylight efficiency 100, Interior depth 100, Scale 25, Finance 57 — each out of 100, then weighted.

Most of what it earns comes from daylight efficiency, and what holds it back most is scale, at 25 out of 100: 38 estimated homes, scored from 0 up to 150.

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 99% daylight figure above deserves.

What the conversion would cost

$360 per square foot all-in across 36,522 sq ft of converted floor, or $13.1M in total — about $346K for each of the 38 homes.

That cost is charged across every converted square foot, including the 296 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 38 homes is $7.5M.

What would have to be true

A $5.7M gap before any grant, $3.4M after the modeled one. The smallest single change that would close it: average unit size 26% down.

The shortfall before any grant is $5.7M. Closing it from the value side means each of the 38 homes finishing at $346K rather than the $197K the model assumes — 76% more. Closing it from the cost side means getting all-in cost down from $360 to $205 per square foot.

A modeled RESIDE grant of $2.3M moves that threshold to $286K a home. That is still above the $197K assumed, leaving $3.4M uncovered, which is why the grant does not unlock this one.

Nor do all four levers have to move. For 1435 Walnut St, one alone would close the gap at:

All four are sliders in the survey, where 1435 Walnut St re-scores against your own numbers.

How it compares in Center City Philadelphia

1435 Walnut St ranks 27th of the 103 buildings screened here, against a median score of 67.

Its floor plate is better lit than 83% of them, and shallower than 83% of them at its deepest interior point. On size it is the 97th 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

21st of 65 zoned CMX5 — the comparison that shares its rules, rents and streets.

65 of the screened buildings are zoned CMX5. 1435 Walnut St ranks 21st 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 36 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: 232 Market St

The screened building closest to 1435 Walnut St in converted floor area is 232 Market St: 37,164 sq ft over 5 stories, against 36,522 sq ft over 6 here.

The two land within a few points of each other — 82 here, 83 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 5,700 ft apart.

Would it qualify for a RESIDE Act grant?

The model awards 1435 Walnut St $2.3M, 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 1435 Walnut St

The 4 closest the screen also covers, from 210 ft away. They are the colored outlines on the plan at the top of this page.

• 1420 Walnut St
  15 stories · 95% daylit · 210 estimated homes · scores 92/100 (Strong candidate)
  about 210 ft away
• 1500 Walnut St
  22 stories · 91% daylit · 537 estimated homes · scores 87/100 (Strong candidate)
  about 280 ft away
• 100 S Broad St
  22 stories · 97% daylit · 610 estimated homes · scores 90/100 (Strong candidate)
  about 460 ft away
• 1524 Walnut St
  21 stories · 86% daylit · 249 estimated homes · scores 81/100 (Strong candidate)
  about 460 ft away