90 S Market St

90 S Market St is a 6-story building in Downtown San Jose with 94% of its floor area within daylight reach of a facade. This screen estimates 86 homes and scores it 87 out of 100 for office-to-residential conversion suitability.

CA-18 · Screened 2026-10-20 · Strong candidate

Also addressed as 55 W San Fernando St: San Jose’s address records place both on this one footprint.

Where 90 S Market 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
90 S Market St

90 S Market 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. 90 S Market 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: 94% 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: 1,089 sq ft per floor that must be renovated but can never be rented as an apartment. The dimension marks the deepest interior point, 51 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: 1,089 sq ft on the floor the screen scores, and 5,443 sq ft over 5 residential floors. The shaded ground floor is converted like the rest and counted as no homes.

OpenStreetMap maps it as a place of worship. Downtown zoning permits it alongside offices, which is why it is on the map, but it is not office space, so this site does not count it as a conversion candidate.

Every floor carries 1,089 sq ft of windowless core — area that must be gutted, seismically braced and sprinklered but can never be rented as an apartment. Across 5 residential floors that is 5,443 sq ft of cost carrying no revenue.

Separated from its neighbors. The city’s map draws this building and the ones beside it as one outline with one height. This outline comes from OpenStreetMap, which maps them separately, and its height is OpenStreetMap’s.

Modeled conversion metrics for 90 S Market St, 2026-10-20.

Suitability scoreStrong candidate	87 / 100
Storiesfrom OpenStreetMap, “Cathedral Basilica of Saint Joseph, way 39018560”, in place of the 90 ft LiDAR height ÷ 12 ft floor-to-floor	6
Floor plateper floor, from the city footprint	17,318 sq ft
Daylight efficiencyshare within 35 ft of a facade	94%
Deepest interior pointviability threshold is 80 ft	51 ft
Windowless coreper floor — renovated but never rentable	1,089 sq ft
BuiltSan Jose does not publish a construction year with this data	—
ZoningDowntown San Jose	DC
Opportunity Zonecensus tract 06085500800, 2018 designation	Yes

The plan: window line, shape and floor rhythm

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

The typical floor has 690 ft of exterior wall, and across 5 residential floors the building carries 3,451 ft of it in total, divided among the 86 homes this screen estimates.

Its plate is moderately compact at 0.46: 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 17.2 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.

Why 90 S Market St scores 87 out of 100

Daylight efficiency 100, Interior depth 72, Scale 57, Finance 100 — each out of 100, then weighted.

Score components for 90 S Market St. Points are the subscore times its weight.

Component	Subscore	Weight	Points
Daylight efficiency94% of the floor area within 35 ft of a facade, scored from 40% up to 90%	100	45%	45.0
Interior depthdeepest interior point 51 ft from a facade, scored from 80 ft down to 40 ft	72	25%	18.1
Scale86 estimated homes, scored from 0 up to 150	57	15%	8.6
Financecompleted value covers conversion cost with 19% 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 57 out of 100: 86 estimated homes, scored from 0 up to 150.

Other buildings screened near 90 S Market St

The 4 closest the screen also covers, from 190 ft away. They are the colored outlines on the plan at the top of this page.

104 S Market St
3 stories · 86% daylit · 47 estimated homes · scores 76/100 (Strong candidate)
about 190 ft away
60 S Market St
15 stories · 79% daylit · 198 estimated homes · scores 78/100 (Strong candidate)
about 210 ft away
95 S Market St
8 stories · 59% daylit · 163 estimated homes · scores 35/100 (Marginal)
about 290 ft away
50 W San Fernando St
17 stories · 70% daylit · 279 estimated homes · scores 55/100 (Worth a feasibility study)
about 340 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.