301 S 1st St
301 S 1st St is a 22-story building in Downtown San Jose with 45% of its floor area within daylight reach of a facade. This screen estimates 1,549 homes and scores it 23 out of 100 for office-to-residential conversion suitability.
CA-18 · Screened 2026-09-12 · Unlikely
Also addressed as 315 S 1st St, 321 S 1st St, 325 S 1st St and 329 S 1st St: San Jose’s address records place all 5 on this one footprint.
Where 301 S 1st St is
Its block in Downtown San Jose, drawn from San Jose's own building outlines and street centerlines.
- Already housing
- Not screened
- 301 S 1st St
This building does not pencil at default assumptions, even with a modeled RESIDE Act grant.
Every floor carries 82,949 sq ft of windowless core — area that must be gutted, seismically braced and sprinklered but can never be rented as an apartment. Across 21 residential floors that is 1,741,929 sq ft of cost carrying no revenue.
Part of this building is already homes. San Jose's rental housing and condominium records list 37 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 19 street addresses across 152,128 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 301 S 1st St, 2026-09-12.
| Suitability scoreUnlikely | 23 / 100 |
|---|---|
| Storiesfrom 262 ft LiDAR height ÷ 12 ft floor-to-floor | 22 |
| Floor plateper floor, from the city footprint | 152,128 sq ft |
| Daylight efficiencyshare within 35 ft of a facade | 45% |
| Deepest interior pointviability threshold is 80 ft | 132 ft |
| Windowless coreper floor — renovated but never rentable | 82,949 sq ft |
| Estimated homesat 750 sq ft average | 1,549 |
| Conversion cost$405/sq ft all-in on 3,194,693 sq ft | $1.29B |
| Gap before grantshortfall against completed value | $635.5M |
| 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 06085500800, 2018 designation | Yes |
The plan: window line, shape and floor rhythm
31 ft of exterior wall for each home the screen estimates — enough for two- and three-bedroom homes across the plan.
The typical floor has 2,291 ft of exterior wall, and across 21 residential floors the building carries 48,106 ft of it in total, divided among the 1,549 homes this screen estimates.
Its plate is elongated at 0.36: a slab or an L, which is why so much of the floor lies within reach of a window: the outline buys daylight that a square plan of the same area would not. How window line and plate shape are measured.
At the model’s 750 sq ft average, the plan works out at about 73.8 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.
Why 301 S 1st St scores 23 out of 100
Daylight efficiency 11, Interior depth 0, Scale 100, Finance 19 — each out of 100, then weighted.
Score components for 301 S 1st St. Points are the subscore times its weight.
| Component | Subscore | Weight | Points |
|---|---|---|---|
| Daylight efficiency45% of the floor area within 35 ft of a facade, scored from 40% up to 90% | 11 | 45% | 4.9 |
| Interior depthdeepest interior point 132 ft from a facade, scored from 80 ft down to 40 ft | 0 | 25% | 0.0 |
| Scale1549 estimated homes, scored from 0 up to 150 | 100 | 15% | 15.0 |
| Financeremaining gap is 48% of conversion cost, scored from 60% down to 0% | 19 | 15% | 2.9 |
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 132 ft from a facade, scored from 80 ft down to 40 ft.
What the conversion would cost
$405 per square foot all-in across 3,194,693 sq ft of converted floor, or $1.29B in total — about $835K for each of the 1,549 homes.
All-in cost per square foot for 301 S 1st 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 1,741,929 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 1,549 homes is $658.3M.
What would have to be true
A $635.5M gap before any grant, $625.5M after the modeled one. The smallest single change that would close it: average unit size 49% down.
The shortfall before any grant is $635.5M. Closing it from the value side means each of the 1,549 homes finishing at $835K rather than the $425K the model assumes — 97% more. Closing it from the cost side means getting all-in cost down from $405 to $206 per square foot.
A modeled RESIDE grant of $10.0M moves that threshold to $829K a home. That is still above the $425K assumed, leaving $625.5M uncovered, which is why the grant does not unlock this one.
Nor do all four levers have to move. For 301 S 1st St, one alone would close the gap at:
Single-assumption flip points for 301 S 1st St, each holding the other three at their defaults.
| Average unit sizethe binding constraint — the least this building would need | 49% downto 385 sq ft |
|---|---|
| Conversion cost per square foot | 75% downto $64/sq ft |
| Completed value per home | 95% upto $829K |
All four are sliders in the survey, where 301 S 1st St re-scores against your own numbers.
How it compares in Downtown San Jose
301 S 1st St ranks 80th of the 82 buildings screened here, against a median score of 64.
Its floor plate is better lit than 4% of them, and shallower than 4% of them at its deepest interior point. On size it is the 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
70th of 72 zoned DC — the comparison that shares its rules, rents and streets.
72 of the screened buildings are zoned DC. 301 S 1st St ranks 70th 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 132 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: 151 Almaden Blvd
The screened building closest to 301 S 1st St in converted floor area is 151 Almaden Blvd: 3,641,188 sq ft over 22 stories, against 3,194,693 sq ft over 22 here.
301 S 1st St scores 23 to its 16, and with the size held roughly equal most of that lead comes from daylight efficiency: 11 out of 100 here, 0 there (39% 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 2,000 ft apart.
Would it qualify for a RESIDE Act grant?
The model awards 301 S 1st 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 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 301 S 1st St
The 4 closest the screen also covers, from 340 ft away. They are the colored outlines on the plan at the top of this page.
- 300 S 1st St7 stories · 75% daylit · 101 estimated homes · scores 62/100 (Worth a feasibility study)about 340 ft away
- 94 E San Carlos St8 stories · 52% daylit · 261 estimated homes · scores 31/100 (Marginal)about 610 ft away
- 200 S Market St5 stories · 79% daylit · 57 estimated homes · scores 69/100 (Worth a feasibility study)about 630 ft away
- 88 E San Carlos St17 stories · 49% daylit · already an apartment buildingabout 730 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.