734 Sansom St

Where 734 Sansom 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

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

The typical floor has 379 ft of exterior wall, and across 5 residential floors the building carries 1,897 ft of it in total, divided among the 42 homes this screen estimates.

Its plate is compact at 0.73: 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 8.4 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.

Why 734 Sansom St scores 79 out of 100

Daylight efficiency 100, Interior depth 87, Scale 28, Finance 52 — each out of 100, then weighted.

Most of what it earns comes from daylight efficiency, and what holds it back most is scale, at 28 out of 100: 42 estimated homes, scored from 0 up to 150.

Built in 1925

Philadelphia records this building as going up in 1925, 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 95% daylight figure above deserves.

What the conversion would cost

$360 per square foot all-in across 42,043 sq ft of converted floor, or $15.1M in total — about $360K for each of the 42 homes.

That cost is charged across every converted square foot, including the 2,156 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 42 homes is $8.3M.

What would have to be true

A $6.9M gap before any grant, $4.4M after the modeled one. The smallest single change that would close it: average unit size 28% down.

The shortfall before any grant is $6.9M. Closing it from the value side means each of the 42 homes finishing at $360K rather than the $197K the model assumes — 83% more. Closing it from the cost side means getting all-in cost down from $360 to $196 per square foot.

A modeled RESIDE grant of $2.5M moves that threshold to $300K a home. That is still above the $197K assumed, leaving $4.4M uncovered, which is why the grant does not unlock this one.

Nor do all four levers have to move. For 734 Sansom St, one alone would close the gap at:

All four are sliders in the survey, where 734 Sansom St re-scores against your own numbers.

How it compares in Center City Philadelphia

734 Sansom St ranks 38th of the 103 buildings screened here, against a median score of 67.

Its floor plate is better lit than 74% of them, and shallower than 68% of them at its deepest interior point. On size it is the 90th 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

28th of 65 zoned CMX5 — the comparison that shares its rules, rents and streets.

65 of the screened buildings are zoned CMX5. 734 Sansom St ranks 28th 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 45 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: 319 N 11th St

The screened building closest to 734 Sansom St in converted floor area is 319 N 11th St: 44,302 sq ft over 6 stories, against 42,043 sq ft over 6 here.

734 Sansom St scores 79 to its 82, and with the size held roughly equal most of that shortfall comes from interior depth: 87 out of 100 here, 99 there (deepest interior point 40 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 3,600 ft apart.

Would it qualify for a RESIDE Act grant?

The model awards 734 Sansom St $2.5M, 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 734 Sansom St

The 4 closest the screen also covers, from 440 ft away. They are the colored outlines on the plan at the top of this page.

• 700 Chestnut St
  6 stories · 100% daylit · 36 estimated homes · scores 83/100 (Strong candidate)
  about 440 ft away
• 105 S 7th St
  4 stories · 63% daylit · 66 estimated homes · scores 33/100 (Marginal)
  about 550 ft away
• 170 S Independence Mall W
  12 stories · 43% daylit · 476 estimated homes · scores 18/100 (Unlikely)
  about 600 ft away
• 819 Chestnut St
  12 stories · 58% daylit · 282 estimated homes · scores 32/100 (Marginal)
  about 620 ft away