55 Hawthorne St
55 Hawthorne St is a 11-story building in Downtown San Francisco with 89% of its floor area within daylight reach of a facade. This screen estimates 163 homes and scores it 94 out of 100 for office-to-residential conversion suitability.
CA-11 · Screened 2026-10-12 · Strong candidate
Where 55 Hawthorne St is
Its block in Downtown San Francisco, drawn from San Francisco's own building outlines and street centerlines.
- Already housing
- Not screened
- 55 Hawthorne St
This building does not pencil at default assumptions, even with a modeled RESIDE Act grant.
Every floor carries 1,928 sq ft of windowless core — area that must be gutted, seismically braced and sprinklered but can never be rented as an apartment. Across 10 residential floors that is 19,276 sq ft of cost carrying no revenue.
Modeled conversion metrics for 55 Hawthorne St, 2026-10-12.
| Suitability scoreStrong candidate | 94 / 100 |
|---|---|
| Storiesfrom 133 ft LiDAR (2010) height ÷ 12 ft floor-to-floor | 11 |
| Floor plateper floor, from the city footprint | 17,230 sq ft |
| Daylight efficiencyshare within 35 ft of a facade | 89% |
| Deepest interior pointviability threshold is 80 ft | 48 ft |
| Windowless coreper floor — renovated but never rentable | 1,928 sq ft |
| Estimated homesat 750 sq ft average | 163 |
| Conversion cost$405/sq ft all-in on 172,300 sq ft | $69.8M |
| Gap before grantshortfall against completed value | $10.1M |
| Modeled RESIDE grantbelow the statutory cap | $9.8M |
| BuiltSan Francisco's own record of the construction year | 1970 |
| ZoningFinancial District/South Beach | C-3-O(SD) |
| Opportunity Zonenot in a 2018 designated tract | No |
The plan: window line, shape and floor rhythm
37 ft of exterior wall for each home the screen estimates — enough for two- and three-bedroom homes across the plan.
The typical floor has 601 ft of exterior wall, and across 10 residential floors the building carries 6,010 ft of it in total, divided among the 163 homes this screen estimates.
Its plate is moderately compact at 0.60: 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 16.3 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.
Why 55 Hawthorne St scores 94 out of 100
Daylight efficiency 98, Interior depth 80, Scale 100, Finance 99 — each out of 100, then weighted.
Score components for 55 Hawthorne St. Points are the subscore times its weight.
| Component | Subscore | Weight | Points |
|---|---|---|---|
| Daylight efficiency89% of the floor area within 35 ft of a facade, scored from 40% up to 90% | 98 | 45% | 43.9 |
| Interior depthdeepest interior point 48 ft from a facade, scored from 80 ft down to 40 ft | 80 | 25% | 20.1 |
| Scale163 estimated homes, scored from 0 up to 150 | 100 | 15% | 15.0 |
| Financeremaining gap is 0% of conversion cost, scored from 60% down to 0% | 99 | 15% | 14.9 |
Most of what it earns comes from daylight efficiency, and what holds it back most is interior depth, at 80 out of 100: deepest interior point 48 ft from a facade, scored from 80 ft down to 40 ft.
Built in 1970
San Francisco records this building as going up in 1970, 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 89% daylight figure above deserves.
What the conversion would cost
$405 per square foot all-in across 172,300 sq ft of converted floor, or $69.8M in total — about $428K for each of the 163 homes.
All-in cost per square foot for 55 Hawthorne 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 19,276 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 163 homes is $59.7M.
What would have to be true
A $10.1M gap before any grant, $344K after the modeled one. The smallest single change that would close it: average unit size under 1% down.
The shortfall before any grant is $10.1M. Closing it from the value side means each of the 163 homes finishing at $428K rather than the $366K the model assumes — 17% more. Closing it from the cost side means getting all-in cost down from $405 to $346 per square foot.
A modeled RESIDE grant of $9.8M moves that threshold to $368K a home. That is still above the $366K assumed, leaving $344K uncovered, which is why the grant does not unlock this one.
Nor do all four levers have to move. For 55 Hawthorne St, one alone would close the gap at:
Single-assumption flip points for 55 Hawthorne St, each holding the other three at their defaults.
| Average unit sizethe binding constraint — the least this building would need | under 1% downto 746 sq ft |
|---|---|
| Circulation efficiency | under 1% upto 80% |
| Completed value per home | 1% upto $368K |
| Conversion cost per square foot | 1% downto $258/sq ft |
All four are sliders in the survey, where 55 Hawthorne St re-scores against your own numbers.
How it compares in Downtown San Francisco
55 Hawthorne St ranks 40th of the 205 buildings screened here, against a median score of 87.
Its floor plate is better lit than 50% of them, and shallower than 51% of them at its deepest interior point. On size it is the 97th 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
37th of 165 in Financial District/South Beach, 10th 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. 55 Hawthorne St ranks 37th 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 48 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). 55 Hawthorne St ranks 10th 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 48 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: 20 Annie St
The screened building closest to 55 Hawthorne St in converted floor area is 20 Annie St: 174,013 sq ft over 10 stories, against 172,300 sq ft over 11 here.
55 Hawthorne St scores 94 to its 100, and with the size held roughly equal most of that shortfall comes from interior depth: 80 out of 100 here, 100 there (deepest interior point 28 ft from a facade, scored from 80 ft down to 40 ft). On the money they part ways: 20 Annie St pencils only with the modeled RESIDE grant, while 55 Hawthorne St falls short even with the modeled grant. The two stand about 1,400 ft apart.
Would it qualify for a RESIDE Act grant?
The model awards 55 Hawthorne St $9.8M, 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 55 Hawthorne 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.
- 75 Hawthorne St20 stories · 72% daylit · 330 estimated homes · scores 61/100 (Worth a feasibility study)about 140 ft away
- 222 2nd St26 stories · 73% daylit · 425 estimated homes · scores 63/100 (Worth a feasibility study)about 260 ft away
- 95 Hawthorne St5 stories · 81% daylit · 57 estimated homes · scores 70/100 (Strong candidate)about 270 ft away
- 170 New Montgomery St8 stories · 74% daylit · 119 estimated homes · scores 62/100 (Worth a feasibility study)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.