555 Montgomery St
555 Montgomery St is a 20-story building in Downtown San Francisco with 84% of its floor area within daylight reach of a facade. This screen estimates 238 homes and scores it 84 out of 100 for office-to-residential conversion suitability.
CA-11 · Screened 2026-10-12 · Strong candidate
Where 555 Montgomery St is
Its block in Downtown San Francisco, drawn from San Francisco's own building outlines and street centerlines.
- Already housing
- Not screened
- 555 Montgomery St
This building does not pencil at default assumptions, even with a modeled RESIDE Act grant.
Every floor carries 2,238 sq ft of windowless core — area that must be gutted, seismically braced and sprinklered but can never be rented as an apartment. Across 19 residential floors that is 42,519 sq ft of cost carrying no revenue.
Modeled conversion metrics for 555 Montgomery St, 2026-10-12.
| Suitability scoreStrong candidate | 84 / 100 |
|---|---|
| Storiesfrom 274 ft LiDAR (2010) height ÷ 12 ft floor-to-floor | 20 |
| Floor plateper floor, from the city footprint | 13,992 sq ft |
| Daylight efficiencyshare within 35 ft of a facade | 84% |
| Deepest interior pointviability threshold is 80 ft | 53 ft |
| Windowless coreper floor — renovated but never rentable | 2,238 sq ft |
| Estimated homesat 750 sq ft average | 238 |
| Conversion cost$405/sq ft all-in on 265,851 sq ft | $107.7M |
| Gap before grantshortfall against completed value | $20.6M |
| Modeled RESIDE grantat the statutory per-award cap | $10.0M |
| BuiltSan Francisco's own record of the construction year | 1985 |
| ZoningChinatown | C-3-O |
| Opportunity Zonenot in a 2018 designated tract | No |
The plan: window line, shape and floor rhythm
38 ft of exterior wall for each home the screen estimates — enough for two- and three-bedroom homes across the plan.
The typical floor has 476 ft of exterior wall, and across 19 residential floors the building carries 9,047 ft of it in total, divided among the 238 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 12.5 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.
Why 555 Montgomery St scores 84 out of 100
Daylight efficiency 88, Interior depth 67, Scale 100, Finance 84 — each out of 100, then weighted.
Score components for 555 Montgomery St. Points are the subscore times its weight.
| Component | Subscore | Weight | Points |
|---|---|---|---|
| Daylight efficiency84% of the floor area within 35 ft of a facade, scored from 40% up to 90% | 88 | 45% | 39.6 |
| Interior depthdeepest interior point 53 ft from a facade, scored from 80 ft down to 40 ft | 67 | 25% | 16.8 |
| Scale238 estimated homes, scored from 0 up to 150 | 100 | 15% | 15.0 |
| Financeremaining gap is 10% of conversion cost, scored from 60% down to 0% | 84 | 15% | 12.5 |
Most of what it earns comes from daylight efficiency, and what holds it back most is interior depth, at 67 out of 100: deepest interior point 53 ft from a facade, scored from 80 ft down to 40 ft.
Built in 1985
San Francisco records this building as going up in 1985, 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 84% daylight figure above deserves.
What the conversion would cost
$405 per square foot all-in across 265,851 sq ft of converted floor, or $107.7M in total — about $452K for each of the 238 homes.
All-in cost per square foot for 555 Montgomery St: base cost plus the code work a change of use triggers.
| Base conversion cost | $260/sq ft |
|---|---|
| Seismic retrofit (change of use) | $45/sq ft |
| Plumbing risers to every unit | $40/sq ft |
| Operable windows and glazing | $30/sq ft |
| Additional egress stair | $18/sq ft |
| Fire sprinklers (NFPA 13R) | $12/sq ft |
| All-in | $405/sq ft |
That cost is charged across every converted square foot, including the 42,519 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 238 homes is $87.1M.
What would have to be true
A $20.6M gap before any grant, $10.6M after the modeled one. The smallest single change that would close it: average unit size 11% down.
The shortfall before any grant is $20.6M. Closing it from the value side means each of the 238 homes finishing at $452K rather than the $366K the model assumes — 24% more. Closing it from the cost side means getting all-in cost down from $405 to $328 per square foot.
A modeled RESIDE grant of $10.0M moves that threshold to $410K a home. That is still above the $366K assumed, leaving $10.6M uncovered, which is why the grant does not unlock this one.
Nor do all four levers have to move. For 555 Montgomery St, one alone would close the gap at:
Single-assumption flip points for 555 Montgomery St, each holding the other three at their defaults.
| Average unit sizethe binding constraint — the least this building would need | 11% downto 669 sq ft |
|---|---|
| Circulation efficiency | 12% upto 90% |
| Completed value per home | 12% upto $410K |
| Conversion cost per square foot | 15% downto $220/sq ft |
All four are sliders in the survey, where 555 Montgomery St re-scores against your own numbers.
How it compares in Downtown San Francisco
555 Montgomery St ranks 110th 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 43% of them at its deepest interior point. On size it is the 73rd 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
5th of 12 in Chinatown, 56th 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. 555 Montgomery St ranks 5th 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 53 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. 555 Montgomery St ranks 56th 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 53 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: 615 Market St
The screened building closest to 555 Montgomery St in converted floor area is 615 Market St: 262,062 sq ft over 20 stories, against 265,851 sq ft over 20 here.
555 Montgomery St scores 84 to its 100, and with the size held roughly equal most of that shortfall comes from interior depth: 67 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: 615 Market St pencils only with the modeled RESIDE grant, while 555 Montgomery St falls short even with the modeled grant. The two stand about 2,200 ft apart.
Would it qualify for a RESIDE Act grant?
The model awards 555 Montgomery 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 555 Montgomery 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.
- 601 Montgomery St20 stories · 83% daylit · 240 estimated homes · scores 83/100 (Strong candidate)about 160 ft away
- 603 Commercial St24 stories · 81% daylit · 303 estimated homes · scores 77/100 (Strong candidate)about 160 ft away
- 540 Montgomery St10 stories · 100% daylit · 62 estimated homes · scores 91/100 (Strong candidate)about 180 ft away
- 417 Montgomery St10 stories · 100% daylit · 80 estimated homes · scores 93/100 (Strong candidate)about 380 ft away
A screen, not a feasibility study, from outlines and heights rather than plans: the method and how to correct a figure. If you know this building’s interior, you know what this model cannot see.