50 N 4th St
50 N 4th St is a 7-story building in Downtown San Jose with 56% of its floor area within daylight reach of a facade. This screen estimates 178 homes and scores it 35 out of 100 for office-to-residential conversion suitability.
CA-18 · Screened 2026-09-12 · Marginal
Also addressed as 60 N 4th St, 70 N 4th St, 55 N 5th St and 63 N 5th St: San Jose’s address records place all 5 on this one footprint.
Where 50 N 4th St is
Its block in Downtown San Jose, drawn from San Jose's own building outlines and street centerlines.
- Already housing
- Not screened
- 50 N 4th St
This building does not pencil at default assumptions, even with a modeled RESIDE Act grant.
Every floor carries 22,233 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 133,400 sq ft of cost carrying no revenue.
Read with caution. This footprint carries 6 street addresses across 50,148 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 50 N 4th St, 2026-09-12.
| Suitability scoreMarginal | 35 / 100 |
|---|---|
| Storiesfrom 87 ft LiDAR height ÷ 12 ft floor-to-floor | 7 |
| Floor plateper floor, from the city footprint | 50,148 sq ft |
| Daylight efficiencyshare within 35 ft of a facade | 56% |
| Deepest interior pointviability threshold is 80 ft | 90 ft |
| Windowless coreper floor — renovated but never rentable | 22,233 sq ft |
| Estimated homesat 750 sq ft average | 178 |
| Conversion cost$405/sq ft all-in on 300,887 sq ft | $121.9M |
| Gap before grantshortfall against completed value | $46.2M |
| 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
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 968 ft of exterior wall, and across 6 residential floors the building carries 5,808 ft of it in total, divided among the 178 homes this screen estimates.
Its plate is moderately compact at 0.67: 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 29.7 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.
Why 50 N 4th St scores 35 out of 100
The weighted components add to 37, but the score is capped at 35 because its deepest interior point is 90 ft from a facade, past the 80 ft threshold beyond which conversion requires carving a light well.
Score components for 50 N 4th St. Points are the subscore times its weight.
| Component | Subscore | Weight | Points |
|---|---|---|---|
| Daylight efficiency56% of the floor area within 35 ft of a facade, scored from 40% up to 90% | 31 | 45% | 14.1 |
| Interior depthdeepest interior point 90 ft from a facade, scored from 80 ft down to 40 ft | 0 | 25% | 0.0 |
| Scale178 estimated homes, scored from 0 up to 150 | 100 | 15% | 15.0 |
| Financeremaining gap is 30% of conversion cost, scored from 60% down to 0% | 50 | 15% | 7.6 |
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 90 ft from a facade, scored from 80 ft down to 40 ft.
What the conversion would cost
$405 per square foot all-in across 300,887 sq ft of converted floor, or $121.9M in total — about $685K for each of the 178 homes.
All-in cost per square foot for 50 N 4th 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 133,400 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 178 homes is $75.7M.
What would have to be true
A $46.2M gap before any grant, $36.2M after the modeled one. The smallest single change that would close it: average unit size 32% down.
The shortfall before any grant is $46.2M. Closing it from the value side means each of the 178 homes finishing at $685K rather than the $425K the model assumes — 61% more. Closing it from the cost side means getting all-in cost down from $405 to $251 per square foot.
A modeled RESIDE grant of $10.0M moves that threshold to $628K a home. That is still above the $425K assumed, leaving $36.2M uncovered, which is why the grant does not unlock this one.
Nor do all four levers have to move. For 50 N 4th St, one alone would close the gap at:
Single-assumption flip points for 50 N 4th St, each holding the other three at their defaults.
| Average unit sizethe binding constraint — the least this building would need | 32% downto 508 sq ft |
|---|---|
| Conversion cost per square foot | 46% downto $140/sq ft |
| Completed value per home | 48% upto $628K |
All four are sliders in the survey, where 50 N 4th St re-scores against your own numbers.
How it compares in Downtown San Jose
50 N 4th St ranks 59th of the 82 buildings screened here, against a median score of 64.
Its floor plate is better lit than 18% of them, and shallower than 26% of them at its deepest interior point. On size it is the 48th 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
50th of 72 zoned DC — the comparison that shares its rules, rents and streets.
72 of the screened buildings are zoned DC. 50 N 4th St ranks 50th 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 90 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: 1 E San Fernando St
The screened building closest to 50 N 4th St in converted floor area is 1 E San Fernando St: 311,020 sq ft over 6 stories, against 300,887 sq ft over 7 here.
1 E San Fernando St scores 56 and 50 N 4th 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 90 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 1,400 ft apart.
Would it qualify for a RESIDE Act grant?
The model awards 50 N 4th 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 50 N 4th St
The 4 closest the screen also covers, from 160 ft away. They are the colored outlines on the plan at the top of this page.
- 156 E St John St7 stories · 83% daylit · already an apartment buildingabout 160 ft away
- 181 E Santa Clara St25 stories · 57% daylit · 819 estimated homes · scores 35/100 (Marginal)about 210 ft away
- 26 N 5th St7 stories · 80% daylit · already an apartment buildingabout 340 ft away
- 225 E Santa Clara St (south)13 stories · 87% daylit · 257 estimated homes · scores 90/100 (Strong candidate)about 440 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.