1431 15th St
1431 15th St is a 10-story building in Greater Downtown Denver with 79% of its floor area within daylight reach of a facade. This screen estimates 311 homes and scores it 62 out of 100 for office-to-residential conversion suitability.
CO-1 · Screened 2026-09-19 · Worth a feasibility study
Also addressed as 1435 15th St, 1437 15th St, 1400 16th St, 1460 16th St, 1480 16th St, 1490 16th St, 1500 Blake St, 1510 Blake St, 1514 Blake St, 1516 Blake St, 1518 Blake St, 1520 Blake St, 1522 Blake St, 1526 Blake St, 1530 Blake St, 1550 Blake St, 1552 Blake St, 1560 Blake St, 1580 Blake St and 1573 Market St: Denver’s address records place all 21 on this one footprint.
Where 1431 15th St is
Its block in Greater Downtown Denver, drawn from Denver's own building outlines and street centerlines.
- Already housing
- Not screened
- 1431 15th St
This building does not pencil at default assumptions, even with a modeled RESIDE Act grant.
Across its 9 residential floors this building carries 79,594 sq ft of windowless core — area that must be gutted, re-plumbed and sprinklered but can never be rented as an apartment.
Read with caution. This footprint carries 21 street addresses across 67,454 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 1431 15th St, 2026-09-19.
| Suitability scoreWorth a feasibility study | 62 / 100 |
|---|---|
| Storiesfrom 125 ft aerial-survey height ÷ 12 ft floor-to-floor | 10 |
| Height bandsfloor plate by floor range, from the city's roof outlines | Floor 1: 70,569 sq ft · Floor 2: 67,454 sq ft · Floor 3: 62,873 sq ft · Floor 4: 53,419 sq ft · Floor 5: 47,806 sq ft · Floor 6: 37,028 sq ft · Floor 7: 35,227 sq ft · Floor 8: 26,096 sq ft · Floors 9–10: 20,938 sq ft |
| Floor platetypical floor, from the city outlines | 67,454 sq ft |
| Daylight efficiencyshare within 35 ft of a facade | 79% |
| Deepest interior pointviability threshold is 80 ft | 69 ft |
| Windowless coretypical floor; the building-wide total is in the text above | 18,274 sq ft |
| Estimated homesat 750 sq ft average | 311 |
| Conversion cost$360/sq ft all-in on 371,780 sq ft | $133.8M |
| Gap before grantshortfall against completed value | $60.4M |
| Modeled RESIDE grantat the statutory per-award cap | $10.0M |
| BuiltDenver does not publish a construction year with this data | — |
| ZoningUnion Station | D-LD |
| Opportunity Zonenot in a 2018 designated tract | No |
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 1,661 ft of exterior wall, and across 9 residential floors the building carries 10,703 ft of it in total, divided among the 311 homes this screen estimates.
Its plate is elongated at 0.31: 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 34.6 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.
Why 1431 15th St scores 62 out of 100
Daylight efficiency 77, Interior depth 28, Scale 100, Finance 37 — each out of 100, then weighted.
Score components for 1431 15th St. Points are the subscore times its weight.
| Component | Subscore | Weight | Points |
|---|---|---|---|
| Daylight efficiency79% of the floor area within 35 ft of a facade, scored from 40% up to 90% | 77 | 45% | 34.7 |
| Interior depthdeepest interior point 69 ft from a facade, scored from 80 ft down to 40 ft | 28 | 25% | 7.1 |
| Scale311 estimated homes, scored from 0 up to 150 | 100 | 15% | 15.0 |
| Financeremaining gap is 38% of conversion cost, scored from 60% down to 0% | 37 | 15% | 5.6 |
Most of what it earns comes from daylight efficiency, and what holds it back most is interior depth, at 28 out of 100: deepest interior point 69 ft from a facade, scored from 80 ft down to 40 ft.
What the conversion would cost
$360 per square foot all-in across 371,780 sq ft of converted floor, or $133.8M in total — about $430K for each of the 311 homes.
All-in cost per square foot for 1431 15th St: base cost plus the code work a change of use triggers.
| Base conversion cost | $260/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 | $360/sq ft |
That cost is charged across every converted square foot, including the 79,594 sq ft of windowless core, which has to be gutted, re-plumbed and sprinklered like the rest of the building and then earns nothing. Against it the model sets a completed value of $236K a home, which for 311 homes is $73.4M.
What would have to be true
A $60.4M gap before any grant, $50.4M after the modeled one. The smallest single change that would close it: average unit size 41% down.
The shortfall before any grant is $60.4M. Closing it from the value side means each of the 311 homes finishing at $430K rather than the $236K the model assumes — 82% more. Closing it from the cost side means getting all-in cost down from $360 to $197 per square foot.
A modeled RESIDE grant of $10.0M moves that threshold to $398K a home. That is still above the $236K assumed, leaving $50.4M uncovered, which is why the grant does not unlock this one.
Nor do all four levers have to move. For 1431 15th St, one alone would close the gap at:
Single-assumption flip points for 1431 15th St, each holding the other three at their defaults.
| Average unit sizethe binding constraint — the least this building would need | 41% downto 445 sq ft |
|---|---|
| Conversion cost per square foot | 52% downto $124/sq ft |
| Completed value per home | 69% upto $398K |
All four are sliders in the survey, where 1431 15th St re-scores against your own numbers.
How it compares in Greater Downtown Denver
1431 15th St ranks 156th of the 214 buildings screened here, against a median score of 72.
Its floor plate is better lit than 37% of them, and shallower than 13% of them at its deepest interior point. On size it is the 67th largest by estimated homes. The full survey of all 214 buildings ranks and maps every one of them, and the list by address links each to its own page.
Within Union Station and the D-LD zone
37th of 55 in Union Station, 21st of 29 zoned D-LD — the comparison that shares its rules, rents and streets.
Denver places 55 of the screened buildings in Union Station. 1431 15th St ranks 37th of them against a median score of 69. 23 score 70 or more, their median deepest interior point is 61 ft from a facade against this building’s 69 ft, and together they would hold an estimated 13,167 homes. The group’s top scorer is 1600 17th St, at 95.
29 of the screened buildings are zoned D-LD. 1431 15th St ranks 21st of them against a median score of 68. 10 score 70 or more, their median deepest interior point is 61 ft from a facade against this building’s 69 ft, and together they would hold an estimated 5,069 homes. The group’s top scorer is 1600 17th St, at 95.
Its nearest match in size: 1606 16th St
The screened building closest to 1431 15th St in converted floor area is 1606 16th St: 367,190 sq ft over 8 stories, against 371,780 sq ft over 10 here.
The two land within a few points of each other — 62 here, 62 there — so at this size the screen reads them as much the same prospect. On the money they sit in the same place: each falls short even with the modeled grant. The two stand about 600 ft apart.
Would it qualify for a RESIDE Act grant?
The model awards 1431 15th 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.
It does not sit in a 2018 designated Opportunity Zone, so it would not draw that Section 201 priority.
Other buildings screened near 1431 15th St
The 4 closest the screen also covers, from 260 ft away. They are the colored outlines on the plan at the top of this page.
- 1510 16th St11 stories · 85% daylit · 125 estimated homes · scores 73/100 (Strong candidate)about 260 ft away
- 1321 15th St12 stories · 76% daylit · 216 estimated homes · scores 72/100 (Strong candidate)about 310 ft away
- 1521 15th St9 stories · 82% daylit · 132 estimated homes · scores 70/100 (Worth a feasibility study)about 390 ft away
- 1601 Blake St8 stories · 90% daylit · 66 estimated homes · scores 81/100 (Strong candidate)about 400 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.