210 S 1st St

210 S 1st St is a 7-story building in Downtown San Jose with 62% of its floor area within daylight reach of a facade. This screen estimates 166 homes and scores it 50 out of 100 for office-to-residential conversion suitability.

CA-18 · Screened 2026-09-12 · Marginal

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Also addressed as 201 S 2nd St: San Jose’s address records place both on this one footprint.

Where 210 S 1st St is

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

Suitability score

0–29

30–49

50–69

70–100

Already housing
Not screened
210 S 1st St

210 S 1st St and the 1,000 ft of Downtown San Jose 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. 210 S 1st St is outlined in its own score color at the outline it covers at ground level. Its windowless core is hatched. The inset places it among every building the screen covers.

Floor plan: 62% of each floor sits within daylight reach of a facade. The shading is daylight, darkest at the windows and gone 35 ft in. The hatched area is windowless core: 15,620 sq ft per floor that must be renovated but can never be rented as an apartment. The dimension marks the deepest interior point, 73 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, fading as it goes, and the hatched stripe left between the lit edges is floor that gets converted and can never be rented: 15,620 sq ft on the floor the screen scores, and 93,719 sq ft over 6 residential floors. The shaded ground floor is converted like the rest and counted as no homes.

This building does not pencil at default assumptions, even with a modeled RESIDE Act grant.

Every floor carries 15,620 sq ft of windowless core — area that must be gutted, seismically braced and sprinklered but can never be rented as an apartment. Across 6 residential floors that is 93,719 sq ft of cost carrying no revenue.

Part of this building is already homes. San Jose's rental housing and condominium records list 35 apartments here, fewer than half the homes this model estimates the building could hold. The figures here treat the whole building as convertible, so read them as an upper bound and check which floors are already housing.

Modeled conversion metrics for 210 S 1st St, 2026-09-12.

Suitability scoreMarginal	50 / 100
Storiesfrom 83 ft LiDAR height ÷ 12 ft floor-to-floor	7
Floor plateper floor, from the city footprint	41,575 sq ft
Daylight efficiencyshare within 35 ft of a facade	62%
Deepest interior pointviability threshold is 80 ft	73 ft
Windowless coreper floor — renovated but never rentable	15,620 sq ft
Estimated homesat 750 sq ft average	166
Conversion cost$405/sq ft all-in on 249,451 sq ft	$101.0M
Gap before grantshortfall against completed value	$30.5M
Modeled RESIDE grantbelow the statutory cap	$10.0M
BuiltSan Jose does not publish a construction year with this data	—
ZoningDowntown San Jose	DC
Opportunity Zonecensus tract 06085500901, 2018 designation	Yes

The plan: window line, shape and floor rhythm

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

The typical floor has 959 ft of exterior wall, and across 6 residential floors the building carries 5,753 ft of it in total, divided among the 166 homes this screen estimates.

Its plate is moderately compact at 0.57: 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 27.7 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.

Why 210 S 1st St scores 50 out of 100

Daylight efficiency 45, Interior depth 18, Scale 100, Finance 66 — each out of 100, then weighted.

Score components for 210 S 1st St. Points are the subscore times its weight.

Component	Subscore	Weight	Points
Daylight efficiency62% of the floor area within 35 ft of a facade, scored from 40% up to 90%	45	45%	20.2
Interior depthdeepest interior point 73 ft from a facade, scored from 80 ft down to 40 ft	18	25%	4.6
Scale166 estimated homes, scored from 0 up to 150	100	15%	15.0
Financeremaining gap is 20% of conversion cost, scored from 60% down to 0%	66	15%	9.9

Most of what it earns comes from daylight efficiency, and what holds it back most is interior depth, at 18 out of 100: deepest interior point 73 ft from a facade, scored from 80 ft down to 40 ft.

What the conversion would cost

$405 per square foot all-in across 249,451 sq ft of converted floor, or $101.0M in total — about $609K for each of the 166 homes.

All-in cost per square foot for 210 S 1st 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 93,719 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 $425K a home, which for 166 homes is $70.5M.

What would have to be true

A $30.5M gap before any grant, $20.5M after the modeled one. The smallest single change that would close it: average unit size 23% down.

The shortfall before any grant is $30.5M. Closing it from the value side means each of the 166 homes finishing at $609K rather than the $425K the model assumes — 43% more. Closing it from the cost side means getting all-in cost down from $405 to $283 per square foot.

A modeled RESIDE grant of $10.0M moves that threshold to $549K a home. That is still above the $425K assumed, leaving $20.5M uncovered, which is why the grant does not unlock this one.

Nor do all four levers have to move. For 210 S 1st St, one alone would close the gap at:

Single-assumption flip points for 210 S 1st St, each holding the other three at their defaults.

Average unit sizethe binding constraint — the least this building would need	23% downto 579 sq ft
Completed value per home	29% upto $549K
Conversion cost per square foot	32% downto $178/sq ft

All four are sliders in the survey, where 210 S 1st St re-scores against your own numbers.

How it compares in Downtown San Jose

210 S 1st St ranks 55th of the 82 buildings screened here, against a median score of 64.

Its floor plate is better lit than 30% of them, and shallower than 39% of them at its deepest interior point. On size it is the 51st largest by estimated homes. The full survey of all 82 buildings ranks and maps every one of them, and the list by address links each to its own page.

Within the DC zone

46th of 72 zoned DC — the comparison that shares its rules, rents and streets.

72 of the screened buildings are zoned DC. 210 S 1st St ranks 46th of them against a median score of 61. 31 score 70 or more, their median deepest interior point is 68 ft from a facade against this building’s 73 ft, and together they would hold an estimated 23,276 homes. The group’s top scorer is 1 Almaden Blvd, at 100.

Its nearest match in size: 95 S Market St

The screened building closest to 210 S 1st St in converted floor area is 95 S Market St: 257,934 sq ft over 8 stories, against 249,451 sq ft over 7 here.

210 S 1st St scores 50 and 95 S Market St only 35, and the difference is a hard fail rather than a matter of degree: the lower one is capped at 35 because its deepest interior point is 95 ft from a facade, past the 80 ft threshold beyond which conversion requires carving a light well. On the money they sit in the same place: each falls short even with the modeled grant. The two stand about 1,200 ft apart.

Would it qualify for a RESIDE Act grant?

The model awards 210 S 1st 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.

This building does sit in census tract 06085500901, a 2018 designated Opportunity Zone, which Section 201 lets HUD favor — one of the few statutory priorities this screen can actually check.

Other buildings screened near 210 S 1st St

The 4 closest the screen also covers, from 310 ft away. They are the colored outlines on the plan at the top of this page.

94 E San Carlos St
8 stories · 52% daylit · 261 estimated homes · scores 31/100 (Marginal)
about 310 ft away
200 S Market St
5 stories · 79% daylit · 57 estimated homes · scores 69/100 (Worth a feasibility study)
about 330 ft away
172 S Market St
14 stories · 81% daylit · 575 estimated homes · scores 75/100 (Strong candidate)
about 400 ft away
101 Paseo De San Antonio
7 stories · 69% daylit · 128 estimated homes · scores 52/100 (Worth a feasibility study)
about 420 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.