505 Sansome St

Where 505 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 438 ft of exterior wall, and across 19 residential floors the building carries 8,325 ft of it in total, divided among the 194 homes this screen estimates.

Its plate is moderately compact at 0.67: 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 10.2 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.

Why 505 Sansome St scores 99 out of 100

Daylight efficiency 100, Interior depth 95, Scale 100, Finance 100 — each out of 100, then weighted.

Every component scores at or near full marks, so nothing in the geometry or the pro-forma is holding this one back — daylight efficiency carries the most weight of the four.

Built in 1981

San Francisco records this building as going up in 1981, which puts it in the late-modern stock.

As a rule, typically the hardest to convert: the deepest plates of any era, large central cores, and floor-to-floor heights tight enough that running residential drainage under a ceiling can be the thing that ends a project. 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 195,271 sq ft of converted floor, or $79.1M in total — about $408K for each of the 194 homes.

That cost is charged across every converted square foot, including the 12,914 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 194 homes is $71.0M.

What would have to be true

A $8.1M gap before any grant, which the modeled $10.0M closes. What would reopen it soonest: completed value per home 3% down.

The shortfall before any grant is $8.1M. Closing it from the value side means each of the 194 homes finishing at $408K rather than the $366K the model assumes — 11% more. Closing it from the cost side means getting all-in cost down from $405 to $364 per square foot.

A modeled RESIDE grant of $10.0M moves that threshold to $356K 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 505 Sansome St:

All four are sliders in the survey, where 505 Sansome St re-scores against your own numbers.

How it compares in Downtown San Francisco

505 Sansome St ranks 25th of the 205 buildings screened here, against a median score of 87.

Its floor plate is better lit than 59% of them, and shallower than 58% of them at its deepest interior point. On size it is the 88th 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

1st of 12 in Chinatown, 18th 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. 505 Sansome St ranks 1st of them against a median score of 80, the top score in the group. 11 score 70 or more, their median deepest interior point is 54 ft from a facade against this building’s 42 ft, and together they would hold an estimated 2,335 homes.

88 of the screened buildings are zoned C-3-O. 505 Sansome St ranks 18th 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 42 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: 88 Kearny St

The screened building closest to 505 Sansome St in converted floor area is 88 Kearny St: 221,903 sq ft over 21 stories, against 195,271 sq ft over 20 here.

The two land within a few points of each other — 99 here, 100 there — so at this size the screen reads them as much the same prospect. On the money they sit in the same place: each pencils only with the modeled RESIDE grant. The two stand about 2,400 ft apart.

Would it qualify for a RESIDE Act grant?

The model awards 505 Sansome 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 505 Sansome St

The 4 closest the screen also covers, from 140 ft away. They are the colored outlines on the plan at the top of this page.

• 545 Sansome St
  9 stories · 97% daylit · 68 estimated homes · scores 91/100 (Strong candidate)
  about 140 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 180 ft away
• 450 Sansome St
  16 stories · 93% daylit · 133 estimated homes · scores 94/100 (Strong candidate)
  about 250 ft away