81 W Santa Clara St
81 W Santa Clara St is a 6-story building in Downtown San Jose with 100% of its floor area within daylight reach of a facade. This screen estimates 32 homes and scores it 88 out of 100 for office-to-residential conversion suitability.
CA-18 · Screened 2026-09-12 · Strong candidate
Where 81 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
- 81 W Santa Clara St
This building's conversion pencils at default assumptions without any subsidy.
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 81 W Santa Clara St, 2026-09-12.
| Suitability scoreStrong candidate | 88 / 100 |
|---|---|
| Storiesfrom 70 ft LiDAR height ÷ 12 ft floor-to-floor | 6 |
| Floor plateper floor, from the city footprint | 6,173 sq ft |
| Daylight efficiencyshare within 35 ft of a facade | 100% |
| Deepest interior pointviability threshold is 80 ft | 27 ft |
| Windowless coreper floor — renovated but never rentable | 0 sq ft |
| Estimated homesat 750 sq ft average | 32 |
| Conversion cost$405/sq ft all-in on 30,863 sq ft | $12.5M |
| Gap before grantpencils unsubsidized | -$1.1M |
| Modeled RESIDE grantbelow the statutory cap | $1.9M |
| 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
62 ft of exterior wall for each home the screen estimates — enough for two- and three-bedroom homes across the plan.
The typical floor has 400 ft of exterior wall, and across 5 residential floors the building carries 1,999 ft of it in total, divided among the 32 homes this screen estimates.
Its plate is moderately compact at 0.49: 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 6.4 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.
Why 81 W Santa Clara St scores 88 out of 100
Daylight efficiency 100, Interior depth 100, Scale 21, Finance 100 — each out of 100, then weighted.
Score components for 81 W Santa Clara 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 27 ft from a facade, scored from 80 ft down to 40 ft | 100 | 25% | 25.0 |
| Scale32 estimated homes, scored from 0 up to 150 | 21 | 15% | 3.2 |
| Financecompleted value covers conversion cost with 24% 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 21 out of 100: 32 estimated homes, scored from 0 up to 150.
What the conversion would cost
$405 per square foot all-in across 30,863 sq ft of converted floor, or $12.5M in total — about $391K for each of the 32 homes.
All-in cost per square foot for 81 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 circulation and service area that earns nothing directly. Against it the model sets a completed value of $425K a home, which for 32 homes is $13.6M.
What would have to be true
This one already clears the bar. The question is how much room it has before it stops.
At $425K a home, completed value covers the $12.5M of work with $1.1M to spare. Value per home would have to fall to $391K — 8% below the assumption — before the conversion stopped penciling, or all-in cost would have to rise from $405 to $441 per square foot. Neither is a wide margin in a market that moves, but this building does not need a grant to work.
Each of these, moved on its own, would be enough to undo that for 81 W Santa Clara St:
Single-assumption flip points for 81 W Santa Clara St, each holding the other three at their defaults.
| Circulation efficiencythe binding constraint — the least this building would need | 21% downto 63% |
|---|---|
| Completed value per home | 22% downto $331K |
| Average unit size | 27% upto 950 sq ft |
| Conversion cost per square foot | 38% upto $358/sq ft |
All four are sliders in the survey, where 81 W Santa Clara St re-scores against your own numbers.
How it compares in Downtown San Jose
81 W Santa Clara St ranks 16th of the 82 buildings screened here, against a median score of 64.
Its floor plate is better lit than 100% of them, and shallower than 100% of them at its deepest interior point. On size it is the 80th 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
13th of 72 zoned DC — the comparison that shares its rules, rents and streets.
72 of the screened buildings are zoned DC. 81 W Santa Clara St ranks 13th 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 27 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: 630 S 1st St
The screened building closest to 81 W Santa Clara St in converted floor area is 630 S 1st St: 30,904 sq ft over 5 stories, against 30,863 sq ft over 6 here.
The two land within a few points of each other — 88 here, 88 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 without a subsidy. The two stand about 4,200 ft apart.
Would it qualify for a RESIDE Act grant?
The model awards 81 W Santa Clara St $1.9M, 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 81 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.
- 1 W Santa Clara St6 stories · 63% daylit · 126 estimated homes · scores 47/100 (Marginal)about 200 ft away
- 84 W Santa Clara St11 stories · 92% daylit · 126 estimated homes · scores 97/100 (Strong candidate)about 260 ft away
- 25 Post St12 stories · 49% daylit · 460 estimated homes · scores 28/100 (Unlikely)about 360 ft away
- 127 Post St20 stories · 62% daylit · 687 estimated homes · scores 35/100 (Marginal)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.