736 Arch St

Where 736 Arch 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

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

The typical floor has 722 ft of exterior wall, and across 6 residential floors the building carries 4,333 ft of it in total, divided among the 129 homes this screen estimates.

Its plate is moderately compact at 0.50: 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 21.5 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.

Why 736 Arch St scores 91 out of 100

Daylight efficiency 100, Interior depth 100, Scale 86, Finance 56 — each out of 100, then weighted.

Most of what it earns comes from daylight efficiency, and what holds it back most is finance, at 56 out of 100: remaining gap is 27% of conversion cost, scored from 60% down to 0%.

Built in 1881

Philadelphia records this building as going up in 1881, which puts it in the pre-1920 stock.

As a rule, the era that converts most readily: load-bearing masonry, small floor plates laid out before deep-plan offices were possible, operable windows and generous floor-to-floor heights. The usual obstacles are not daylight but hazardous materials, lifts and bringing structure up to current code. 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 97% daylight figure above deserves.

What the conversion would cost

$360 per square foot all-in across 125,191 sq ft of converted floor, or $45.1M in total — about $349K for each of the 129 homes.

That cost is charged across every converted square foot, including the 3,841 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 129 homes is $25.4M.

What would have to be true

A $19.7M gap before any grant, $12.0M after the modeled one. The smallest single change that would close it: average unit size 28% down.

The shortfall before any grant is $19.7M. Closing it from the value side means each of the 129 homes finishing at $349K rather than the $197K the model assumes — 78% more. Closing it from the cost side means getting all-in cost down from $360 to $203 per square foot.

A modeled RESIDE grant of $7.7M moves that threshold to $289K a home. That is still above the $197K assumed, leaving $12.0M uncovered, which is why the grant does not unlock this one.

Nor do all four levers have to move. For 736 Arch St, one alone would close the gap at:

All four are sliders in the survey, where 736 Arch St re-scores against your own numbers.

How it compares in Center City Philadelphia

736 Arch St ranks 11th of the 100 buildings screened here, against a median score of 67.

Its floor plate is better lit than 78% of them, and shallower than 76% of them at its deepest interior point. On size it is the 63rd largest by estimated homes. The full survey of all 100 buildings ranks and maps every one of them, and the list by address links each to its own page.

Within the CMX5 zone

11th of 63 zoned CMX5 — the comparison that shares its rules, rents and streets.

63 of the screened buildings are zoned CMX5. 736 Arch St ranks 11th of them against a median score of 67. 28 score 70 or more, their median deepest interior point is 57 ft from a facade against this building’s 39 ft, and together they would hold an estimated 30,185 homes. The group’s top scorer is 112 N Broad St, at 93.

Its nearest match in size: 990 Spring Garden St

The screened building closest to 736 Arch St in converted floor area is 990 Spring Garden St: 134,550 sq ft over 7 stories, against 125,191 sq ft over 7 here.

736 Arch St scores 91 to its 63, and with the size held roughly equal most of that lead comes from daylight efficiency: 100 out of 100 here, 72 there (76% of the floor area within 35 ft of a facade, scored from 40% up to 90%). On the money they sit in the same place: each falls short even with the modeled grant. The two stand about 3,200 ft apart.

Would it qualify for a RESIDE Act grant?

The model awards 736 Arch St $7.7M, 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 736 Arch St

The 4 closest the screen also covers, from 360 ft away. They are the colored outlines on the plan at the top of this page.

• 701 Market St
  5 stories · 40% daylit · 247 estimated homes · scores 15/100 (Unlikely)
  about 360 ft away
• 117 N 8th St
  8 stories · 95% daylit · 63 estimated homes · scores 84/100 (Strong candidate)
  about 420 ft away
• 801 Arch St
  6 stories · 71% daylit · 133 estimated homes · scores 56/100 (Worth a feasibility study)
  about 440 ft away
• 150 N Independence Mall W
  8 stories · 52% daylit · 407 estimated homes · scores 25/100 (Unlikely)
  about 580 ft away