500 Sansome St

Where 500 Sansome St is

Its block in Downtown San Francisco, drawn from San Francisco's own building outlines and street centerlines.

The plan: window line, shape and floor rhythm

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

The typical floor has 519 ft of exterior wall, and across 7 residential floors the building carries 3,633 ft of it in total, divided among the 97 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 13.9 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.

Why 500 Sansome St scores 72 out of 100

Daylight efficiency 81, Interior depth 51, Scale 65, Finance 83 — each out of 100, then weighted.

Most of what it earns comes from daylight efficiency, and what holds it back most is interior depth, at 51 out of 100: deepest interior point 60 ft from a facade, scored from 80 ft down to 40 ft.

Built in 1929

San Francisco records this building as going up in 1929, 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 81% daylight figure above deserves.

What the conversion would cost

$405 per square foot all-in across 113,296 sq ft of converted floor, or $45.9M in total — about $473K for each of the 97 homes.

That cost is charged across every converted square foot, including the 21,876 sq ft of windowless core, which has to be gutted, seismically braced and sprinklered like the rest of the building and then earns nothing. Against it the model sets a completed value of $366K a home, which for 97 homes is $35.5M.

What would have to be true

A $10.4M gap before any grant, $4.6M after the modeled one. The smallest single change that would close it: average unit size 10% down.

The shortfall before any grant is $10.4M. Closing it from the value side means each of the 97 homes finishing at $473K rather than the $366K the model assumes — 29% more. Closing it from the cost side means getting all-in cost down from $405 to $313 per square foot.

A modeled RESIDE grant of $5.8M moves that threshold to $413K a home. That is still above the $366K assumed, leaving $4.6M uncovered, which is why the grant does not unlock this one.

Nor do all four levers have to move. For 500 Sansome St, one alone would close the gap at:

All four are sliders in the survey, where 500 Sansome St re-scores against your own numbers.

How it compares in Downtown San Francisco

500 Sansome St ranks 144th of the 205 buildings screened here, against a median score of 87.

Its floor plate is better lit than 33% of them, and shallower than 31% of them at its deepest interior point. On size it is the 127th largest by estimated homes. The full survey of all 205 buildings ranks and maps every one of them, and the list by address links each to its own page.

Within Chinatown and the C-3-O zone

10th of 12 in Chinatown, 74th of 88 zoned C-3-O — the comparison that shares its rules, rents and streets.

San Francisco places 12 of the screened buildings in Chinatown. 500 Sansome St ranks 10th of them against a median score of 80. 11 score 70 or more, their median deepest interior point is 54 ft from a facade against this building’s 60 ft, and together they would hold an estimated 2,335 homes. The group’s top scorer is 505 Sansome St, at 99.

88 of the screened buildings are zoned C-3-O. 500 Sansome St ranks 74th of them against a median score of 89. 76 score 70 or more, their median deepest interior point is 44 ft from a facade against this building’s 60 ft, and together they would hold an estimated 21,444 homes. The group’s top scorer is 266 Bush St, at 100.

Its nearest match in size: 255 Battery St

The screened building closest to 500 Sansome St in converted floor area is 255 Battery St: 100,774 sq ft over 8 stories, against 113,296 sq ft over 8 here.

The two land within a few points of each other — 72 here, 73 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 700 ft apart.

Would it qualify for a RESIDE Act grant?

The model awards 500 Sansome St $5.8M, 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 500 Sansome St

The 4 closest the screen also covers, from 180 ft away. They are the colored outlines on the plan at the top of this page.

• 505 Sansome St
  20 stories · 93% daylit · 194 estimated homes · scores 99/100 (Strong candidate)
  about 180 ft away
• 450 Sansome St
  16 stories · 93% daylit · 133 estimated homes · scores 94/100 (Strong candidate)
  about 180 ft away
• 545 Sansome St
  9 stories · 97% daylit · 68 estimated homes · scores 91/100 (Strong candidate)
  about 230 ft away
• 475 Sansome St
  20 stories · 76% daylit · 336 estimated homes · scores 74/100 (Strong candidate)
  about 290 ft away