221 Main St

Where 221 Main 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

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

The typical floor has 822 ft of exterior wall, and across 15 residential floors the building carries 12,323 ft of it in total, divided among the 363 homes this screen estimates.

Its plate is moderately compact at 0.64: 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 24.2 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.

Why 221 Main St scores 51 out of 100

Daylight efficiency 52, Interior depth 22, Scale 100, Finance 47 — 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 22 out of 100: deepest interior point 71 ft from a facade, scored from 80 ft down to 40 ft.

Built in 1973

San Francisco records this building as going up in 1973, 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 66% daylight figure above deserves.

What the conversion would cost

$405 per square foot all-in across 515,532 sq ft of converted floor, or $208.8M in total — about $575K for each of the 363 homes.

That cost is charged across every converted square foot, including the 174,902 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 363 homes is $132.9M.

What would have to be true

A $75.9M gap before any grant, $65.9M after the modeled one. The smallest single change that would close it: average unit size 33% down.

The shortfall before any grant is $75.9M. Closing it from the value side means each of the 363 homes finishing at $575K rather than the $366K the model assumes — 57% more. Closing it from the cost side means getting all-in cost down from $405 to $258 per square foot.

A modeled RESIDE grant of $10.0M moves that threshold to $548K a home. That is still above the $366K assumed, leaving $65.9M uncovered, which is why the grant does not unlock this one.

Nor do all four levers have to move. For 221 Main St, one alone would close the gap at:

All four are sliders in the survey, where 221 Main St re-scores against your own numbers.

How it compares in Downtown San Francisco

221 Main St ranks 191st of the 205 buildings screened here, against a median score of 87.

Its floor plate is better lit than 6% of them, and shallower than 10% of them at its deepest interior point. On size it is the 41st 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 Financial District/South Beach and the C-3-O(SD) zone

157th of 165 in Financial District/South Beach, 60th of 66 zoned C-3-O(SD) — the comparison that shares its rules, rents and streets.

San Francisco places 165 of the screened buildings in Financial District/South Beach. 221 Main St ranks 157th of them against a median score of 88. 121 score 70 or more, their median deepest interior point is 47 ft from a facade against this building’s 71 ft, and together they would hold an estimated 40,456 homes. The group’s top scorer is 870 Market St, at 100.

66 of the screened buildings are zoned C-3-O(SD). 221 Main St ranks 60th of them against a median score of 72. 37 score 70 or more, their median deepest interior point is 59 ft from a facade against this building’s 71 ft, and together they would hold an estimated 18,546 homes. The group’s top scorer is 140 New Montgomery St, at 100.

Its nearest match in size: 1275 Market St

The screened building closest to 221 Main St in converted floor area is 1275 Market St: 508,290 sq ft over 17 stories, against 515,532 sq ft over 16 here.

The two land within a few points of each other — 51 here, 52 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 8,200 ft apart.

Would it qualify for a RESIDE Act grant?

The model awards 221 Main 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 221 Main St

The 4 closest the screen also covers, from 200 ft away. They are the colored outlines on the plan at the top of this page.

• 211 Main St
  17 stories · 70% daylit · 286 estimated homes · scores 53/100 (Worth a feasibility study)
  about 200 ft away
• 101 Howard St
  5 stories · 78% daylit · 57 estimated homes · scores 62/100 (Worth a feasibility study)
  about 200 ft away
• 201 Spear St
  18 stories · 87% daylit · 268 estimated homes · scores 92/100 (Strong candidate)
  about 310 ft away
• 180 Howard St
  13 stories · 77% daylit · 178 estimated homes · scores 67/100 (Worth a feasibility study)
  about 420 ft away