245 Post St

245 Post St is a 6-story building in Downtown San Francisco with 100% of its floor area within daylight reach of a facade. This screen estimates 35 homes and scores it 89 out of 100 for office-to-residential conversion suitability.

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

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Also addressed as 251 Post St and 253 Post St: San Francisco’s address records place all 3 on this one footprint.

Where 245 Post St is

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

Suitability score

0–29

30–49

50–69

70–100

Already housing
Not screened
245 Post St

245 Post 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. 245 Post 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.

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, 29 ft from the nearest window. A–A is where the section beside it is cut.

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 245 Post St, 2026-10-12.

Suitability scoreStrong candidate	89 / 100
Storiesfrom 85 ft LiDAR (2010) height ÷ 12 ft floor-to-floor	6
Floor plateper floor, from the city footprint	6,654 sq ft
Daylight efficiencyshare within 35 ft of a facade	100%
Deepest interior pointviability threshold is 80 ft	29 ft
Windowless coreper floor — renovated but never rentable	0 sq ft
Estimated homesat 750 sq ft average	35
Conversion cost$405/sq ft all-in on 33,269 sq ft	$13.5M
Gap before grantshortfall against completed value	$664K
Modeled RESIDE grantbelow the statutory cap	$2.1M
BuiltSan Francisco's own record of the construction year	1908
ZoningFinancial District/South Beach	C-3-R
Opportunity Zonenot in a 2018 designated tract	No

The plan: window line, shape and floor rhythm

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

The typical floor has 441 ft of exterior wall, and across 5 residential floors the building carries 2,205 ft of it in total, divided among the 35 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 7.0 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.

Why 245 Post St scores 89 out of 100

Daylight efficiency 100, Interior depth 100, Scale 23, Finance 100 — each out of 100, then weighted.

Score components for 245 Post St. Points are the subscore times its weight.

Component	Subscore	Weight	Points
Daylight efficiency100% of the floor area within 35 ft of a facade, scored from 40% up to 90%	100	45%	45.0
Interior depthdeepest interior point 29 ft from a facade, scored from 80 ft down to 40 ft	100	25%	25.0
Scale35 estimated homes, scored from 0 up to 150	23	15%	3.5
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 23 out of 100: 35 estimated homes, scored from 0 up to 150.

Built in 1908

San Francisco records this building as going up in 1908, 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 100% daylight figure above deserves.

What the conversion would cost

$405 per square foot all-in across 33,269 sq ft of converted floor, or $13.5M in total — about $385K for each of the 35 homes.

All-in cost per square foot for 245 Post 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 35 homes is $12.8M.

What would have to be true

A $664K gap before any grant, which the modeled $2.1M closes. What would reopen it soonest: circulation efficiency 10% down.

The shortfall before any grant is $664K. Closing it from the value side means each of the 35 homes finishing at $385K rather than the $366K the model assumes — 5% more. Closing it from the cost side means getting all-in cost down from $405 to $385 per square foot.

A modeled RESIDE grant of $2.1M moves that threshold to $325K 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 245 Post St:

Single-assumption flip points for 245 Post 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	11% downto $325K
Conversion cost per square foot	17% upto $303/sq ft

All four are sliders in the survey, where 245 Post St re-scores against your own numbers.

How it compares in Downtown San Francisco

245 Post St ranks 91st 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 86% of them at its deepest interior point. On size it is the 195th 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-R zone

76th of 165 in Financial District/South Beach, 17th of 25 zoned C-3-R — the comparison that shares its rules, rents and streets.

San Francisco places 165 of the screened buildings in Financial District/South Beach. 245 Post St ranks 76th 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 29 ft, and together they would hold an estimated 40,456 homes. The group’s top scorer is 870 Market St, at 100.

25 of the screened buildings are zoned C-3-R. 245 Post St ranks 17th of them against a median score of 90. 21 score 70 or more, their median deepest interior point is 32 ft from a facade against this building’s 29 ft, and together they would hold an estimated 2,773 homes. The group’s top scorer is 870 Market St, at 100.

Its nearest match in size: 312 Sutter St

The screened building closest to 245 Post St in converted floor area is 312 Sutter St: 34,151 sq ft over 6 stories, against 33,269 sq ft over 6 here.

The two land within a few points of each other — 89 here, 89 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 500 ft apart.

Would it qualify for a RESIDE Act grant?

The model awards 245 Post St $2.1M, 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.