720 California St

Where 720 California 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

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

The typical floor has 464 ft of exterior wall, and across 6 residential floors the building carries 2,786 ft of it in total, divided among the 72 homes this screen estimates.

Its plate is compact at 0.79: 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 12.0 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.

Why 720 California St scores 74 out of 100

Daylight efficiency 88, Interior depth 56, Scale 48, Finance 89 — each out of 100, then weighted.

Most of what it earns comes from daylight efficiency, and what holds it back most is scale, at 48 out of 100: 72 estimated homes, scored from 0 up to 150.

Built in 1926

San Francisco records this building as going up in 1926, 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 84% daylight figure above deserves.

What the conversion would cost

$405 per square foot all-in across 81,283 sq ft of converted floor, or $32.9M in total — about $457K for each of the 72 homes.

That cost is charged across every converted square foot, including the 12,945 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 72 homes is $26.4M.

What would have to be true

A $6.6M gap before any grant, $2.2M after the modeled one. The smallest single change that would close it: average unit size 7% down.

The shortfall before any grant is $6.6M. Closing it from the value side means each of the 72 homes finishing at $457K rather than the $366K the model assumes — 25% more. Closing it from the cost side means getting all-in cost down from $405 to $324 per square foot.

A modeled RESIDE grant of $4.3M moves that threshold to $397K a home. That is still above the $366K assumed, leaving $2.2M uncovered, which is why the grant does not unlock this one.

Nor do all four levers have to move. For 720 California St, one alone would close the gap at:

All four are sliders in the survey, where 720 California St re-scores against your own numbers.

How it compares in Downtown San Francisco

720 California St ranks 135th of the 205 buildings screened here, against a median score of 87.

Its floor plate is better lit than 42% of them, and shallower than 34% of them at its deepest interior point. On size it is the 145th 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-G zone

8th of 12 in Chinatown, 13th of 22 zoned C-3-G — the comparison that shares its rules, rents and streets.

San Francisco places 12 of the screened buildings in Chinatown. 720 California St ranks 8th 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 57 ft, and together they would hold an estimated 2,335 homes. The group’s top scorer is 505 Sansome St, at 99.

22 of the screened buildings are zoned C-3-G. 720 California St ranks 13th of them against a median score of 76. 13 score 70 or more, their median deepest interior point is 51 ft from a facade against this building’s 57 ft, and together they would hold an estimated 2,588 homes. The group’s top scorer is 40 Leavenworth St, at 92.

Its nearest match in size: 234 1st St

The screened building closest to 720 California St in converted floor area is 234 1st St: 81,356 sq ft over 7 stories, against 81,283 sq ft over 7 here.

720 California St scores 74 to its 93, and with the size held roughly equal most of that shortfall comes from interior depth: 56 out of 100 here, 100 there (deepest interior point 37 ft from a facade, scored from 80 ft down to 40 ft). On the money they part ways: 234 1st St pencils only with the modeled RESIDE grant, while 720 California St 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 720 California St $4.3M, 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 720 California St

The 4 closest the screen also covers, from 390 ft away. They are the colored outlines on the plan at the top of this page.

• 636 California St
  33 stories · 79% daylit · 444 estimated homes · scores 71/100 (Strong candidate)
  about 390 ft away
• 601 California St
  22 stories · 83% daylit · 265 estimated homes · scores 81/100 (Strong candidate)
  about 540 ft away
• 401 Kearny St
  5 stories · 78% daylit · 62 estimated homes · scores 68/100 (Worth a feasibility study)
  about 610 ft away
• 580 California St
  23 stories · 80% daylit · 304 estimated homes · scores 72/100 (Strong candidate)
  about 700 ft away