15 E Santa Clara St
15 E Santa Clara St is a 12-story building in Downtown San Jose with 53% of its floor area within daylight reach of a facade. This screen estimates 867 homes and scores it 32 out of 100 for office-to-residential conversion suitability.
CA-18 · Screened 2026-09-12 · Marginal
Also addressed as 17 E Santa Clara St, 27 E Santa Clara St, 35 E Santa Clara St and 39 E Santa Clara St: San Jose’s address records place all 5 on this one footprint.
Where 15 E 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
- 15 E Santa Clara St
This building does not pencil at default assumptions, even with a modeled RESIDE Act grant.
Every floor carries 66,199 sq ft of windowless core — area that must be gutted, seismically braced and sprinklered but can never be rented as an apartment. Across 11 residential floors that is 728,191 sq ft of cost carrying no revenue.
Part of this building is already homes. San Jose's rental housing and condominium records list 191 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.
Read with caution. This footprint carries 18 street addresses across 140,094 sq ft, which usually means the city’s GIS has merged a block or complex into a single polygon rather than describing one convertible building.
Modeled conversion metrics for 15 E Santa Clara St, 2026-09-12.
| Suitability scoreMarginal | 32 / 100 |
|---|---|
| Storiesfrom 142 ft LiDAR height ÷ 12 ft floor-to-floor | 12 |
| Floor plateper floor, from the city footprint | 140,094 sq ft |
| Daylight efficiencyshare within 35 ft of a facade | 53% |
| Deepest interior pointviability threshold is 80 ft | 119 ft |
| Windowless coreper floor — renovated but never rentable | 66,199 sq ft |
| Estimated homesat 750 sq ft average | 867 |
| Conversion cost$405/sq ft all-in on 1,541,037 sq ft | $624.1M |
| Gap before grantshortfall against completed value | $255.6M |
| Modeled RESIDE grantat the statutory per-award cap | $10.0M |
| BuiltSan Jose does not publish a construction year with this data | — |
| ZoningDowntown San Jose | DC |
| Opportunity Zonecensus tract 06085501000, 2018 designation | Yes |
The plan: window line, shape and floor rhythm
34 ft of exterior wall for each home the screen estimates — enough for two- and three-bedroom homes across the plan.
The typical floor has 2,676 ft of exterior wall, and across 11 residential floors the building carries 29,441 ft of it in total, divided among the 867 homes this screen estimates.
Its plate is highly articulated at 0.25: a long, notched or wing-shaped outline with far more facade than its area needs — wasteful as an office envelope, and close to ideal for apartments. How window line and plate shape are measured.
At the model’s 750 sq ft average, the plan works out at about 78.8 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.
Why 15 E Santa Clara St scores 32 out of 100
Daylight efficiency 25, Interior depth 0, Scale 100, Finance 34 — each out of 100, then weighted.
Score components for 15 E Santa Clara St. Points are the subscore times its weight.
| Component | Subscore | Weight | Points |
|---|---|---|---|
| Daylight efficiency53% of the floor area within 35 ft of a facade, scored from 40% up to 90% | 25 | 45% | 11.5 |
| Interior depthdeepest interior point 119 ft from a facade, scored from 80 ft down to 40 ft | 0 | 25% | 0.0 |
| Scale867 estimated homes, scored from 0 up to 150 | 100 | 15% | 15.0 |
| Financeremaining gap is 39% of conversion cost, scored from 60% down to 0% | 34 | 15% | 5.2 |
Most of what it earns comes from scale, and what holds it back most is interior depth, at 0 out of 100: deepest interior point 119 ft from a facade, scored from 80 ft down to 40 ft.
What the conversion would cost
$405 per square foot all-in across 1,541,037 sq ft of converted floor, or $624.1M in total — about $720K for each of the 867 homes.
All-in cost per square foot for 15 E 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 728,191 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 867 homes is $368.5M.
What would have to be true
A $255.6M gap before any grant, $245.6M after the modeled one. The smallest single change that would close it: average unit size 40% down.
The shortfall before any grant is $255.6M. Closing it from the value side means each of the 867 homes finishing at $720K rather than the $425K the model assumes — 69% more. Closing it from the cost side means getting all-in cost down from $405 to $239 per square foot.
A modeled RESIDE grant of $10.0M moves that threshold to $708K a home. That is still above the $425K assumed, leaving $245.6M uncovered, which is why the grant does not unlock this one.
Nor do all four levers have to move. For 15 E Santa Clara St, one alone would close the gap at:
Single-assumption flip points for 15 E Santa Clara St, each holding the other three at their defaults.
| Average unit sizethe binding constraint — the least this building would need | 40% downto 450 sq ft |
|---|---|
| Conversion cost per square foot | 61% downto $101/sq ft |
| Completed value per home | 67% upto $708K |
All four are sliders in the survey, where 15 E Santa Clara St re-scores against your own numbers.
How it compares in Downtown San Jose
15 E Santa Clara St ranks 70th of the 82 buildings screened here, against a median score of 64.
Its floor plate is better lit than 16% of them, and shallower than 7% of them at its deepest interior point. On size it is the 4th 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
60th of 72 zoned DC — the comparison that shares its rules, rents and streets.
72 of the screened buildings are zoned DC. 15 E Santa Clara St ranks 60th 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 119 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: 333 W San Fernando St
The screened building closest to 15 E Santa Clara St in converted floor area is 333 W San Fernando St: 1,646,447 sq ft over 21 stories, against 1,541,037 sq ft over 12 here.
15 E Santa Clara St scores 32 to its 23, and with the size held roughly equal most of that lead comes from daylight efficiency: 25 out of 100 here, 11 there (46% of the floor area within 35 ft of a facade, scored from 40% up to 90%). On the money they sit in the same place: each falls short even with the modeled grant. The two stand about 2,400 ft apart.
Would it qualify for a RESIDE Act grant?
The model awards 15 E Santa Clara 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 06085501000, 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 15 E Santa Clara St
The 4 closest the screen also covers, from 290 ft away. They are the colored outlines on the plan at the top of this page.
- 4 N 2nd St15 stories · 76% daylit · 212 estimated homes · scores 71/100 (Strong candidate)about 290 ft away
- 75 E Santa Clara St16 stories · 79% daylit · 210 estimated homes · scores 78/100 (Strong candidate)about 350 ft away
- 1 W Santa Clara St6 stories · 63% daylit · 126 estimated homes · scores 47/100 (Marginal)about 390 ft away
- 50 E St John St5 stories · 74% daylit · 213 estimated homes · scores 68/100 (Worth a feasibility study)about 410 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.