138 Minna St
138 Minna St is a 9-story building in Downtown San Francisco with 99% of its floor area within daylight reach of a facade. This screen estimates 133 homes and scores it 98 out of 100 for office-to-residential conversion suitability.
CA-11 · Screened 2026-10-12 · Strong candidate
Also addressed as 643 Mission St, 100 New Montgomery St, 114 New Montgomery St, 116 New Montgomery St, 118 New Montgomery St, 122 New Montgomery St and 126 New Montgomery St: San Francisco’s address records place all 8 on this one footprint.
Where 138 Minna St is
Its block in Downtown San Francisco, drawn from San Francisco's own building outlines and street centerlines.
- Already housing
- Not screened
- 138 Minna St
This building does not pencil on its own, but a modeled RESIDE Act grant would close the gap if the building qualified for one.
Every floor carries 121 sq ft of windowless core — area that must be gutted, seismically braced and sprinklered but can never be rented as an apartment. Across 8 residential floors that is 969 sq ft of cost carrying no revenue.
Modeled conversion metrics for 138 Minna St, 2026-10-12.
| Suitability scoreStrong candidate | 98 / 100 |
|---|---|
| Storiesfrom 111 ft LiDAR (2010) height ÷ 12 ft floor-to-floor | 9 |
| Floor plateper floor, from the city footprint | 15,721 sq ft |
| Daylight efficiencyshare within 35 ft of a facade | 99% |
| Deepest interior pointviability threshold is 80 ft | 38 ft |
| Windowless coreper floor — renovated but never rentable | 121 sq ft |
| Estimated homesat 750 sq ft average | 133 |
| Conversion cost$405/sq ft all-in on 125,768 sq ft | $50.9M |
| Gap before grantshortfall against completed value | $2.3M |
| Modeled RESIDE grantbelow the statutory cap | $8.0M |
| BuiltSan Francisco's own record of the construction year | 1901 |
| ZoningFinancial District/South Beach | C-3-O(SD) |
| Opportunity Zonenot in a 2018 designated tract | No |
The plan: window line, shape and floor rhythm
41 ft of exterior wall for each home the screen estimates — enough for two- and three-bedroom homes across the plan.
The typical floor has 675 ft of exterior wall, and across 8 residential floors the building carries 5,402 ft of it in total, divided among the 133 homes this screen estimates.
Its plate is elongated at 0.43: a slab or an L, which is why so much of the floor lies within reach of a window: the outline buys daylight that a square plan of the same area would not. How window line and plate shape are measured.
At the model’s 750 sq ft average, the plan works out at about 16.6 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.
Why 138 Minna St scores 98 out of 100
Daylight efficiency 100, Interior depth 100, Scale 89, Finance 100 — each out of 100, then weighted.
Score components for 138 Minna St. Points are the subscore times its weight.
| Component | Subscore | Weight | Points |
|---|---|---|---|
| Daylight efficiency99% of the floor area within 35 ft of a facade, scored from 40% up to 90% | 100 | 45% | 45.0 |
| Interior depthdeepest interior point 38 ft from a facade, scored from 80 ft down to 40 ft | 100 | 25% | 25.0 |
| Scale133 estimated homes, scored from 0 up to 150 | 89 | 15% | 13.3 |
| Financecompleted value covers conversion cost with 11% to spare, which tops out the component | 100 | 15% | 15.0 |
Most of what it earns comes from daylight efficiency, and what holds it back most is scale, at 89 out of 100: 133 estimated homes, scored from 0 up to 150.
Built in 1901
San Francisco records this building as going up in 1901, which puts it in the pre-1920 stock.
As a rule, the era that converts most readily: load-bearing masonry, small floor plates laid out before deep-plan offices were possible, operable windows and generous floor-to-floor heights. The usual obstacles are not daylight but hazardous materials, lifts and bringing structure up to current code. 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 99% daylight figure above deserves.
What the conversion would cost
$405 per square foot all-in across 125,768 sq ft of converted floor, or $50.9M in total — about $383K for each of the 133 homes.
All-in cost per square foot for 138 Minna 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 969 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 $2.3M gap before any grant, which the modeled $8.0M closes. What would reopen it soonest: circulation efficiency 10% down.
The shortfall before any grant is $2.3M. Closing it from the value side means each of the 133 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 $8.0M 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 138 Minna St:
Single-assumption flip points for 138 Minna St, each holding the other three at their defaults.
| Circulation efficiencythe binding constraint — the least this building would need | 10% downto 72% |
|---|---|
| Average unit size | 11% upto 832 sq ft |
| Completed value per home | 12% downto $323K |
| Conversion cost per square foot | 17% upto $305/sq ft |
All four are sliders in the survey, where 138 Minna St re-scores against your own numbers.
How it compares in Downtown San Francisco
138 Minna St ranks 29th of the 205 buildings screened here, against a median score of 87.
Its floor plate is better lit than 69% of them, and shallower than 66% 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 Financial District/South Beach and the C-3-O(SD) zone
27th of 165 in Financial District/South Beach, 5th 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. 138 Minna St ranks 27th 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 38 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). 138 Minna St ranks 5th 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 38 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: 1 Claude Ln
The screened building closest to 138 Minna St in converted floor area is 1 Claude Ln: 128,142 sq ft over 9 stories, against 125,768 sq ft over 9 here.
138 Minna St scores 98 to its 76, and with the size held roughly equal most of that lead comes from interior depth: 100 out of 100 here, 59 there (deepest interior point 57 ft from a facade, scored from 80 ft down to 40 ft). On the money they part ways: 1 Claude Ln falls short even with the modeled grant, while 138 Minna St pencils only with the modeled RESIDE grant. The two stand about 1,600 ft apart.
Would it qualify for a RESIDE Act grant?
The model awards 138 Minna 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 138 Minna St
The 4 closest the screen also covers, from 110 ft away. They are the colored outlines on the plan at the top of this page.
- 647 Mission St5 stories · 100% daylit · 26 estimated homes · scores 88/100 (Strong candidate)about 110 ft away
- 150 Minna St6 stories · 88% daylit · 67 estimated homes · scores 86/100 (Strong candidate)about 170 ft away
- 617 Mission St6 stories · 96% daylit · 62 estimated homes · scores 90/100 (Strong candidate)about 170 ft away
- 140 New Montgomery St26 stories · 100% daylit · 368 estimated homes · scores 100/100 (Strong candidate)about 180 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.