1 W Santa Clara St
1 W Santa Clara St is a 6-story building in Downtown San Jose with 63% of its floor area within daylight reach of a facade. This screen estimates 126 homes and scores it 47 out of 100 for office-to-residential conversion suitability.
CA-18 · Screened 2026-09-12 · Marginal
Also addressed as 55 W Santa Clara St: San Jose’s address records place both on this one footprint.
Where 1 W Santa Clara St is
Its block in Downtown San Jose, drawn from San Jose's own building outlines and street centerlines.
- Already housing
- Not screened
- 1 W Santa Clara St
This building does not pencil at default assumptions, even with a modeled RESIDE Act grant.
Every floor carries 13,836 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 69,182 sq ft of cost carrying no revenue.
Modeled conversion metrics for 1 W Santa Clara St, 2026-09-12.
| Suitability scoreMarginal | 47 / 100 |
|---|---|
| Storiesfrom 66 ft LiDAR height ÷ 12 ft floor-to-floor | 6 |
| Floor plateper floor, from the city footprint | 37,573 sq ft |
| Daylight efficiencyshare within 35 ft of a facade | 63% |
| Deepest interior pointviability threshold is 80 ft | 75 ft |
| Windowless coreper floor — renovated but never rentable | 13,836 sq ft |
| Estimated homesat 750 sq ft average | 126 |
| Conversion cost$405/sq ft all-in on 187,866 sq ft | $76.1M |
| Gap before grantshortfall against completed value | $22.5M |
| Modeled RESIDE grantbelow the statutory cap | $7.6M |
| 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
33 ft of exterior wall for each home the screen estimates — enough for two- and three-bedroom homes across the plan.
The typical floor has 830 ft of exterior wall, and across 5 residential floors the building carries 4,150 ft of it in total, divided among the 126 homes this screen estimates.
Its plate is moderately compact at 0.69: 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 25.2 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.
Why 1 W Santa Clara St scores 47 out of 100
Daylight efficiency 46, Interior depth 12, Scale 84, Finance 67 — each out of 100, then weighted.
Score components for 1 W Santa Clara St. Points are the subscore times its weight.
| Component | Subscore | Weight | Points |
|---|---|---|---|
| Daylight efficiency63% of the floor area within 35 ft of a facade, scored from 40% up to 90% | 46 | 45% | 20.9 |
| Interior depthdeepest interior point 75 ft from a facade, scored from 80 ft down to 40 ft | 12 | 25% | 3.1 |
| Scale126 estimated homes, scored from 0 up to 150 | 84 | 15% | 12.6 |
| Financeremaining gap is 20% of conversion cost, scored from 60% down to 0% | 67 | 15% | 10.1 |
Most of what it earns comes from daylight efficiency, and what holds it back most is interior depth, at 12 out of 100: deepest interior point 75 ft from a facade, scored from 80 ft down to 40 ft.
What the conversion would cost
$405 per square foot all-in across 187,866 sq ft of converted floor, or $76.1M in total — about $604K for each of the 126 homes.
All-in cost per square foot for 1 W Santa Clara 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 69,182 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 126 homes is $53.5M.
What would have to be true
A $22.5M gap before any grant, $15.0M after the modeled one. The smallest single change that would close it: average unit size 19% down.
The shortfall before any grant is $22.5M. Closing it from the value side means each of the 126 homes finishing at $604K rather than the $425K the model assumes — 42% more. Closing it from the cost side means getting all-in cost down from $405 to $285 per square foot.
A modeled RESIDE grant of $7.6M moves that threshold to $544K a home. That is still above the $425K assumed, leaving $15.0M uncovered, which is why the grant does not unlock this one.
Nor do all four levers have to move. For 1 W Santa Clara St, one alone would close the gap at:
Single-assumption flip points for 1 W Santa Clara St, each holding the other three at their defaults.
| Average unit sizethe binding constraint — the least this building would need | 19% downto 605 sq ft |
|---|---|
| Circulation efficiency | 24% upto 99% |
| Completed value per home | 28% upto $544K |
| Conversion cost per square foot | 31% downto $180/sq ft |
All four are sliders in the survey, where 1 W Santa Clara St re-scores against your own numbers.
How it compares in Downtown San Jose
1 W Santa Clara St ranks 58th of the 82 buildings screened here, against a median score of 64.
Its floor plate is better lit than 34% of them, and shallower than 37% of them at its deepest interior point. On size it is the 64th 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
49th of 72 zoned DC — the comparison that shares its rules, rents and streets.
72 of the screened buildings are zoned DC. 1 W Santa Clara St ranks 49th 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 75 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: 100 W San Fernando St
The screened building closest to 1 W Santa Clara St in converted floor area is 100 W San Fernando St: 186,490 sq ft over 7 stories, against 187,866 sq ft over 6 here.
1 W Santa Clara St scores 47 to its 79, and with the size held roughly equal most of that shortfall comes from interior depth: 12 out of 100 here, 68 there (deepest interior point 53 ft from a facade, scored from 80 ft down to 40 ft). On the money they sit in the same place: each falls short even with the modeled grant. The two stand about 1,300 ft apart.
Would it qualify for a RESIDE Act grant?
The model awards 1 W Santa Clara St $7.6M, 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 06085500800, 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 1 W Santa Clara St
The 4 closest the screen also covers, from 200 ft away. They are the colored outlines on the plan at the top of this page.
- 81 W Santa Clara St6 stories · 100% daylit · 32 estimated homes · scores 88/100 (Strong candidate)about 200 ft away
- 25 Post St12 stories · 49% daylit · 460 estimated homes · scores 28/100 (Unlikely)about 320 ft away
- 84 W Santa Clara St11 stories · 92% daylit · 126 estimated homes · scores 97/100 (Strong candidate)about 350 ft away
- 15 E Santa Clara St12 stories · 53% daylit · 867 estimated homes · scores 32/100 (Marginal)about 390 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.