450 Sansome St

Where 450 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

43 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 15 residential floors the building carries 5,685 ft of it in total, divided among the 133 homes this screen estimates.

Its plate is compact at 0.78: 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 8.9 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.

Why 450 Sansome St scores 94 out of 100

Daylight efficiency 100, Interior depth 84, Scale 89, Finance 100 — 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 84 out of 100: deepest interior point 46 ft from a facade, scored from 80 ft down to 40 ft.

Built in 1967

San Francisco records this building as going up in 1967, 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 93% daylight figure above deserves.

What the conversion would cost

$405 per square foot all-in across 134,407 sq ft of converted floor, or $54.4M in total — about $409K for each of the 133 homes.

That cost is charged across every converted square foot, including the 9,095 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 133 homes is $48.7M.

What would have to be true

A $5.8M gap before any grant, which the modeled $8.0M closes. What would reopen it soonest: circulation efficiency 4% down.

The shortfall before any grant is $5.8M. Closing it from the value side means each of the 133 homes finishing at $409K rather than the $366K the model assumes — 12% more. Closing it from the cost side means getting all-in cost down from $405 to $362 per square foot.

A modeled RESIDE grant of $8.0M moves that threshold to $349K a home. That is below the assumed value, which is why this building counts as unlocked by the grant — subject to it qualifying under the law's vacant-and-abandoned test, which this data cannot show.

Each of these, moved on its own, would be enough to undo that for 450 Sansome St:

All four are sliders in the survey, where 450 Sansome St re-scores against your own numbers.

How it compares in Downtown San Francisco

450 Sansome St ranks 38th of the 205 buildings screened here, against a median score of 87.

Its floor plate is better lit than 58% of them, and shallower than 53% of them at its deepest interior point. On size it is the 113th 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

2nd of 12 in Chinatown, 26th 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. 450 Sansome St ranks 2nd 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 46 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. 450 Sansome St ranks 26th 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 46 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: 240 Montgomery St

The screened building closest to 450 Sansome St in converted floor area is 240 Montgomery St: 131,965 sq ft over 17 stories, against 134,407 sq ft over 16 here.

450 Sansome St scores 94 to its 99, and with the size held roughly equal most of that shortfall comes from interior depth: 84 out of 100 here, 100 there (deepest interior point 36 ft from a facade, scored from 80 ft down to 40 ft). On the money they sit in the same place: each pencils only with the modeled RESIDE grant. The two stand about 1,100 ft apart.

Would it qualify for a RESIDE Act grant?

The model awards 450 Sansome St $8.0M, 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 450 Sansome St

The 4 closest the screen also covers, from 160 ft away. They are the colored outlines on the plan at the top of this page.

• 301 Battery St
  8 stories · 72% daylit · 148 estimated homes · scores 68/100 (Worth a feasibility study)
  about 160 ft away
• 500 Sansome St
  8 stories · 81% daylit · 97 estimated homes · scores 72/100 (Strong candidate)
  about 180 ft away
• 475 Sansome St
  20 stories · 76% daylit · 336 estimated homes · scores 74/100 (Strong candidate)
  about 230 ft away
• 505 Sansome St
  20 stories · 93% daylit · 194 estimated homes · scores 99/100 (Strong candidate)
  about 250 ft away