540 Montgomery St

540 Montgomery St is a 10-story building in Downtown San Francisco with 100% of its floor area within daylight reach of a facade. This screen estimates 62 homes and scores it 91 out of 100 for office-to-residential conversion suitability.

CA-11 · Screened 2026-10-12 · Strong candidate

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Also addressed as 550 Montgomery St: San Francisco’s address records place both on this one footprint.

Where 540 Montgomery St is

Its block in Downtown San Francisco, drawn from San Francisco's own building outlines and street centerlines.

505 Sansome St: scores 99 out of 100456 Montgomery St: scores 96 out of 100450 Sansome St: scores 94 out of 100417 Montgomery St: scores 93 out of 100545 Sansome St: scores 91 out of 100483 Sacramento St: scores 90 out of 100555 Montgomery St: scores 84 out of 100601 Montgomery St: scores 83 out of 100464 California St: scores 82 out of 100603 Commercial St: scores 77 out of 100350 California St: scores 77 out of 100475 Sansome St: scores 74 out of 100500 Sansome St: scores 72 out of 100530 Kearny St: scores 71 out of 100301 Battery St: scores 68 out of 100537 Sacramento St: scores 64 out of 1009996908483827774686491COMMERCIAL STCLAY STMERCHANT STSACRAMENTO STLEIDESDORFF STMONTGOMERY STSANSOME STN100 ftDowntown San Francisco
Suitability score
0–29
30–49
50–69
70–100
  • Already housing
  • Not screened
  • 540 Montgomery St
540 Montgomery St and the 1,000 ft of Downtown San Francisco around it. The streets are drawn at the width of the right-of-way they run down, sidewalks included, and named, and every building on these blocks is drawn. What is left open and stippled is neither: a surface lot, a plaza or a vacant parcel. The screened buildings are colored by the ramp above, the same one the district map uses, carry their score, and each is a link to its own page. Each casts a shadow as long as its measured height lets it, so towers stand out from the low buildings around them; the unscreened buildings have no measured height and cast none. 540 Montgomery St is outlined in its own score color at the outline it covers at ground level. The inset places it among every building the screen covers.
31 ftAA50 ftDaylit 100%
Floor plan: 100% of each floor sits within daylight reach of a facade, with no dead core at all. The shading is daylight, darkest at the windows and gone 35 ft in. The dimension marks the deepest interior point, 31 ft from the nearest window. A–A is where the section beside it is cut.
Ground floor · no homesDaylit10 floors25 ft
Section A–A: cut across the depth of the plate, through the middle of the core. Daylight reaches 35 ft in from every facade, and here it meets in the middle: the plate is thin enough that no floor is left windowless. The shaded ground floor is converted like the rest and counted as no homes.

This building does not pencil on its own, but a modeled RESIDE Act grant would close the gap if the building qualified for one.

This footprint has no windowless core at all: every point on the floor plate is within 35 ft of a facade, which is unusual and is the main reason it scores as well as it does.

Modeled conversion metrics for 540 Montgomery St, 2026-10-12.

Suitability scoreStrong candidate91 / 100
Storiesfrom 127 ft LiDAR (2010) height ÷ 12 ft floor-to-floor10
Floor plateper floor, from the city footprint6,513 sq ft
Daylight efficiencyshare within 35 ft of a facade100%
Deepest interior pointviability threshold is 80 ft31 ft
Windowless coreper floor — renovated but never rentable0 sq ft
Estimated homesat 750 sq ft average62
Conversion cost$405/sq ft all-in on 58,619 sq ft$23.7M
Gap before grantshortfall against completed value$1.0M
Modeled RESIDE grantbelow the statutory cap$3.7M
BuiltSan Francisco's own record of the construction year1931
ZoningChinatownC-3-O
Opportunity Zonenot in a 2018 designated tractNo

The plan: window line, shape and floor rhythm

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

The typical floor has 341 ft of exterior wall, and across 9 residential floors the building carries 3,068 ft of it in total, divided among the 62 homes this screen estimates.

Its plate is moderately compact at 0.70: 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 6.9 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.

Why 540 Montgomery St scores 91 out of 100

Daylight efficiency 100, Interior depth 100, Scale 41, Finance 100 — each out of 100, then weighted.

Score components for 540 Montgomery St. Points are the subscore times its weight.

ComponentSubscoreWeightPoints
Daylight efficiency100% of the floor area within 35 ft of a facade, scored from 40% up to 90%10045%45.0
Interior depthdeepest interior point 31 ft from a facade, scored from 80 ft down to 40 ft10025%25.0
Scale62 estimated homes, scored from 0 up to 1504115%6.2
Financecompleted value covers conversion cost with 11% to spare, which tops out the component10015%15.0

Most of what it earns comes from daylight efficiency, and what holds it back most is scale, at 41 out of 100: 62 estimated homes, scored from 0 up to 150.

Built in 1931

San Francisco records this building as going up in 1931, which puts it in the interwar stock.

As a rule, steel or concrete frames with punched windows and plates still narrow enough for daylight to reach the middle, often with high ceilings. Among the most convertible stock there is, and the reason so many early conversions were of buildings this age. 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 100% daylight figure above deserves.

What the conversion would cost

$405 per square foot all-in across 58,619 sq ft of converted floor, or $23.7M in total — about $383K for each of the 62 homes.

All-in cost per square foot for 540 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 circulation and service area that earns nothing directly. Against it the model sets a completed value of $366K a home, which for 62 homes is $22.7M.

What would have to be true

A $1.0M gap before any grant, which the modeled $3.7M closes. What would reopen it soonest: circulation efficiency 10% down.

The shortfall before any grant is $1.0M. Closing it from the value side means each of the 62 homes finishing at $383K rather than the $366K the model assumes — 5% more. Closing it from the cost side means getting all-in cost down from $405 to $387 per square foot.

A modeled RESIDE grant of $3.7M moves that threshold to $323K 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 540 Montgomery St:

Single-assumption flip points for 540 Montgomery St, each holding the other three at their defaults.

Circulation efficiencythe binding constraint — the least this building would need10% downto 72%
Average unit size12% upto 837 sq ft
Completed value per home12% downto $323K
Conversion cost per square foot18% upto $306/sq ft

All four are sliders in the survey, where 540 Montgomery St re-scores against your own numbers.

How it compares in Downtown San Francisco

540 Montgomery St ranks 56th of the 205 buildings screened here, against a median score of 87.

Its floor plate is better lit than 100% of them, and shallower than 80% of them at its deepest interior point. On size it is the 159th 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

3rd of 12 in Chinatown, 33rd 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. 540 Montgomery St ranks 3rd 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 31 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. 540 Montgomery St ranks 33rd 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 31 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: 60 Maiden Ln

The screened building closest to 540 Montgomery St in converted floor area is 60 Maiden Ln: 55,943 sq ft over 10 stories, against 58,619 sq ft over 10 here.

The two land within a few points of each other — 91 here, 91 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 2,200 ft apart.

Would it qualify for a RESIDE Act grant?

The model awards 540 Montgomery St $3.7M, 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 540 Montgomery St

The 4 closest the screen also covers, from 180 ft away. They are the colored outlines on the plan at the top of this page.

  • 555 Montgomery St
    20 stories · 84% daylit · 238 estimated homes · scores 84/100 (Strong candidate)
    about 180 ft away
  • 603 Commercial St
    24 stories · 81% daylit · 303 estimated homes · scores 77/100 (Strong candidate)
    about 220 ft away
  • 475 Sansome St
    20 stories · 76% daylit · 336 estimated homes · scores 74/100 (Strong candidate)
    about 260 ft away
  • 601 Montgomery St
    20 stories · 83% daylit · 240 estimated homes · scores 83/100 (Strong candidate)
    about 260 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.