636 California St

Where 636 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

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 510 ft of exterior wall, and across 32 residential floors the building carries 16,317 ft of it in total, divided among the 444 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 13.9 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.

Why 636 California St scores 71 out of 100

Daylight efficiency 79, Interior depth 41, Scale 100, Finance 69 — 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 41 out of 100: deepest interior point 64 ft from a facade, scored from 80 ft down to 40 ft.

Built in 1963

San Francisco records this building as going up in 1963, which puts it in the post-war stock.

As a rule, the period when plates got deep and facades became curtain wall: sealed glazing, lower floor-to-floor heights, and mechanical systems designed around a sealed box. Conversions here usually turn on whether the windows can be made to open and whether ceilings survive new plumbing. 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 79% daylight figure above deserves.

What the conversion would cost

$405 per square foot all-in across 524,939 sq ft of converted floor, or $212.6M in total — about $479K for each of the 444 homes.

That cost is charged across every converted square foot, including the 108,140 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 444 homes is $162.5M.

What would have to be true

A $50.1M gap before any grant, $40.1M after the modeled one. The smallest single change that would close it: average unit size 20% down.

The shortfall before any grant is $50.1M. Closing it from the value side means each of the 444 homes finishing at $479K rather than the $366K the model assumes — 31% more. Closing it from the cost side means getting all-in cost down from $405 to $310 per square foot.

A modeled RESIDE grant of $10.0M moves that threshold to $456K a home. That is still above the $366K assumed, leaving $40.1M uncovered, which is why the grant does not unlock this one.

Nor do all four levers have to move. For 636 California St, one alone would close the gap at:

All four are sliders in the survey, where 636 California St re-scores against your own numbers.

How it compares in Downtown San Francisco

636 California St ranks 145th of the 205 buildings screened here, against a median score of 87.

Its floor plate is better lit than 31% of them, and shallower than 18% of them at its deepest interior point. On size it is the 26th 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

11th of 12 in Chinatown, 75th 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. 636 California St ranks 11th 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 64 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. 636 California St ranks 75th 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 64 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: 340 Mission St

The screened building closest to 636 California St in converted floor area is 340 Mission St: 560,386 sq ft over 30 stories, against 524,939 sq ft over 33 here.

636 California St scores 71 to its 63, and with the size held roughly equal most of that lead comes from daylight efficiency: 79 out of 100 here, 71 there (75% 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 2,600 ft apart.

Would it qualify for a RESIDE Act grant?

The model awards 636 California St $10.0M, 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 636 California St

The 4 closest the screen also covers, from 240 ft away. They are the colored outlines on the plan at the top of this page.

• 601 California St
  22 stories · 83% daylit · 265 estimated homes · scores 81/100 (Strong candidate)
  about 240 ft away
• 580 California St
  23 stories · 80% daylit · 304 estimated homes · scores 72/100 (Strong candidate)
  about 310 ft away
• 530 Kearny St
  10 stories · 78% daylit · 134 estimated homes · scores 71/100 (Strong candidate)
  about 340 ft away
• 401 Kearny St
  5 stories · 78% daylit · 62 estimated homes · scores 68/100 (Worth a feasibility study)
  about 370 ft away