170 S Market St
170 S Market St is a 20-story building in Downtown San Jose with 43% of its floor area within daylight reach of a facade. This screen estimates 797 homes and scores it 20 out of 100 for office-to-residential conversion suitability.
CA-18 · Screened 2026-09-12 · Unlikely
Where 170 S Market St is
Its block in Downtown San Jose, drawn from San Jose's own building outlines and street centerlines.
- Already housing
- Not screened
- 170 S Market St
This building does not pencil at default assumptions, even with a modeled RESIDE Act grant.
Every floor carries 52,155 sq ft of windowless core — area that must be gutted, seismically braced and sprinklered but can never be rented as an apartment. Across 19 residential floors that is 990,953 sq ft of cost carrying no revenue.
Modeled conversion metrics for 170 S Market St, 2026-09-12.
| Suitability scoreUnlikely | 20 / 100 |
|---|---|
| Storiesfrom 244 ft LiDAR height ÷ 12 ft floor-to-floor | 20 |
| Floor plateper floor, from the city footprint | 91,486 sq ft |
| Daylight efficiencyshare within 35 ft of a facade | 43% |
| Deepest interior pointviability threshold is 80 ft | 140 ft |
| Windowless coreper floor — renovated but never rentable | 52,155 sq ft |
| Estimated homesat 750 sq ft average | 797 |
| Conversion cost$405/sq ft all-in on 1,738,231 sq ft | $704.0M |
| Gap before grantshortfall against completed value | $365.3M |
| 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
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 1,444 ft of exterior wall, and across 19 residential floors the building carries 27,440 ft of it in total, divided among the 797 homes this screen estimates.
Its plate is moderately compact at 0.55: 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 41.9 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.
Why 170 S Market St scores 20 out of 100
Daylight efficiency 6, Interior depth 0, Scale 100, Finance 16 — each out of 100, then weighted.
Score components for 170 S Market St. Points are the subscore times its weight.
| Component | Subscore | Weight | Points |
|---|---|---|---|
| Daylight efficiency43% of the floor area within 35 ft of a facade, scored from 40% up to 90% | 6 | 45% | 2.7 |
| Interior depthdeepest interior point 140 ft from a facade, scored from 80 ft down to 40 ft | 0 | 25% | 0.0 |
| Scale797 estimated homes, scored from 0 up to 150 | 100 | 15% | 15.0 |
| Financeremaining gap is 50% of conversion cost, scored from 60% down to 0% | 16 | 15% | 2.4 |
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 140 ft from a facade, scored from 80 ft down to 40 ft.
What the conversion would cost
$405 per square foot all-in across 1,738,231 sq ft of converted floor, or $704.0M in total — about $883K for each of the 797 homes.
All-in cost per square foot for 170 S Market 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 990,953 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 797 homes is $338.7M.
What would have to be true
A $365.3M gap before any grant, $355.3M after the modeled one. The smallest single change that would close it: average unit size 51% down.
The shortfall before any grant is $365.3M. Closing it from the value side means each of the 797 homes finishing at $883K rather than the $425K the model assumes — 108% more. Closing it from the cost side means getting all-in cost down from $405 to $195 per square foot.
A modeled RESIDE grant of $10.0M moves that threshold to $871K a home. That is still above the $425K assumed, leaving $355.3M uncovered, which is why the grant does not unlock this one.
Nor do all four levers have to move. For 170 S Market St, one alone would close the gap at:
Single-assumption flip points for 170 S Market St, each holding the other three at their defaults.
| Average unit sizethe binding constraint — the least this building would need | 51% downto 366 sq ft |
|---|---|
| Conversion cost per square foot | 79% downto $56/sq ft |
| Completed value per home | 105% upto $871K |
All four are sliders in the survey, where 170 S Market St re-scores against your own numbers.
How it compares in Downtown San Jose
170 S Market St ranks 81st of the 82 buildings screened here, against a median score of 64.
Its floor plate is better lit than 2% of them, and shallower than 2% of them at its deepest interior point. On size it is the 7th 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
71st of 72 zoned DC — the comparison that shares its rules, rents and streets.
72 of the screened buildings are zoned DC. 170 S Market St ranks 71st 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 140 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: 300 Park Ave
The screened building closest to 170 S Market St in converted floor area is 300 Park Ave: 1,742,580 sq ft over 19 stories, against 1,738,231 sq ft over 20 here.
170 S Market St scores 20 to its 35, and with the size held roughly equal most of that shortfall comes from daylight efficiency: 6 out of 100 here, 40 there (60% 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 2,100 ft apart.
Would it qualify for a RESIDE Act grant?
The model awards 170 S Market 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 170 S Market St
The 4 closest the screen also covers, from 320 ft away. They are the colored outlines on the plan at the top of this page.
- 50 W San Fernando St22 stories · 70% daylit · 366 estimated homes · scores 54/100 (Worth a feasibility study)about 320 ft away
- 172 S Market St14 stories · 81% daylit · 575 estimated homes · scores 75/100 (Strong candidate)about 320 ft away
- 104 S Market St8 stories · 86% daylit · 164 estimated homes · scores 87/100 (Strong candidate)about 370 ft away
- 200 S Market St5 stories · 79% daylit · 57 estimated homes · scores 69/100 (Worth a feasibility study)about 450 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.