1781 15th St
1781 15th St is a 10-story building in Greater Downtown Denver with 69% of its floor area within daylight reach of a facade. This screen estimates 248 homes and scores it 51 out of 100 for office-to-residential conversion suitability.
CO-1 · Screened 2026-09-19 · Worth a feasibility study
Also addressed as 1783 15th St, 1799 15th St, 1513 Wynkoop St, 1515 Wynkoop St, 1517 Wynkoop St and 1519 Wynkoop St: Denver’s address records place all 7 on this one footprint.
Where 1781 15th St is
Its block in Greater Downtown Denver, drawn from Denver's own building outlines and street centerlines.
- Already housing
- Not screened
- 1781 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 104,936 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 7 street addresses across 48,189 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 1781 15th St, 2026-09-19.
| Suitability scoreWorth a feasibility study | 51 / 100 |
|---|---|
| Storiesfrom 119 ft aerial-survey height ÷ 12 ft floor-to-floor | 10 |
| Height bandsfloor plate by floor range, from the city's roof outlines | Floors 1–2: 49,624 sq ft · Floors 3–5: 48,189 sq ft · Floors 6–7: 46,531 sq ft · Floor 8: 28,162 sq ft · Floors 9–10: 11,365 sq ft |
| Floor platetypical floor, from the city outlines | 48,189 sq ft |
| Daylight efficiencyshare within 35 ft of a facade | 69% |
| Deepest interior pointviability threshold is 80 ft | 71 ft |
| Windowless coretypical floor; the building-wide total is in the text above | 16,327 sq ft |
| Estimated homesat 750 sq ft average | 248 |
| Conversion cost$360/sq ft all-in on 338,144 sq ft | $121.7M |
| Gap before grantshortfall against completed value | $63.2M |
| 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 1,110 ft of exterior wall, and across 9 residential floors the building carries 8,412 ft of it in total, divided among the 248 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 27.6 homes per floor. Its floors are not alike, though: the typical floor's deepest interior point is 71 ft from a facade, while its worst floor reaches 78 ft. The score follows the typical floor, so a podium that could not hold a bedroom does not by itself sink a slim tower above it — but it is there, and it is part of what would have to be drawn around.
Why 1781 15th St scores 51 out of 100
Daylight efficiency 58, Interior depth 23, Scale 100, Finance 27 — each out of 100, then weighted.
Score components for 1781 15th St. Points are the subscore times its weight.
| Component | Subscore | Weight | Points |
|---|---|---|---|
| Daylight efficiency69% of the floor area within 35 ft of a facade, scored from 40% up to 90% | 58 | 45% | 26.1 |
| Interior depthdeepest interior point 71 ft from a facade, scored from 80 ft down to 40 ft | 23 | 25% | 5.8 |
| Scale248 estimated homes, scored from 0 up to 150 | 100 | 15% | 15.0 |
| Financeremaining gap is 44% of conversion cost, scored from 60% down to 0% | 27 | 15% | 4.1 |
Most of what it earns comes from daylight efficiency, and what holds it back most is interior depth, at 23 out of 100: deepest interior point 71 ft from a facade, scored from 80 ft down to 40 ft.
What the conversion would cost
$360 per square foot all-in across 338,144 sq ft of converted floor, or $121.7M in total — about $491K for each of the 248 homes.
All-in cost per square foot for 1781 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 104,936 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 248 homes is $58.5M.
What would have to be true
A $63.2M gap before any grant, $53.2M after the modeled one. The smallest single change that would close it: average unit size 48% down.
The shortfall before any grant is $63.2M. Closing it from the value side means each of the 248 homes finishing at $491K rather than the $236K the model assumes — 108% more. Closing it from the cost side means getting all-in cost down from $360 to $173 per square foot.
A modeled RESIDE grant of $10.0M moves that threshold to $451K a home. That is still above the $236K assumed, leaving $53.2M uncovered, which is why the grant does not unlock this one.
Nor do all four levers have to move. For 1781 15th St, one alone would close the gap at:
Single-assumption flip points for 1781 15th St, each holding the other three at their defaults.
| Average unit sizethe binding constraint — the least this building would need | 48% downto 394 sq ft |
|---|---|
| Conversion cost per square foot | 61% downto $103/sq ft |
| Completed value per home | 91% upto $451K |
All four are sliders in the survey, where 1781 15th St re-scores against your own numbers.
How it compares in Greater Downtown Denver
1781 15th St ranks 191st of the 214 buildings screened here, against a median score of 72.
Its floor plate is better lit than 11% of them, and shallower than 11% of them at its deepest interior point. On size it is the 91st 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
51st of 55 in Union Station, 28th of 29 zoned D-LD — the comparison that shares its rules, rents and streets.
Denver places 55 of the screened buildings in Union Station. 1781 15th St ranks 51st 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 71 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. 1781 15th St ranks 28th 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 71 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: 1101 13th St
The screened building closest to 1781 15th St in converted floor area is 1101 13th St: 342,702 sq ft over 12 stories, against 338,144 sq ft over 10 here.
1781 15th St scores 51 to its 71, and with the size held roughly equal most of that shortfall comes from daylight efficiency: 58 out of 100 here, 87 there (83% 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 2,300 ft apart.
Would it qualify for a RESIDE Act grant?
The model awards 1781 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 1781 15th St
The 4 closest the screen also covers, from 220 ft away. They are the colored outlines on the plan at the top of this page.
- 1750 16th St13 stories · 69% daylit · 280 estimated homes · scores 49/100 (Marginal)about 220 ft away
- 1449 Wynkoop St7 stories · 82% daylit · already a condominium buildingabout 250 ft away
- 1500 Wynkoop St7 stories · 90% daylit · 61 estimated homes · scores 80/100 (Strong candidate)about 270 ft away
- 1450 Wynkoop St6 stories · 86% daylit · already a condominium buildingabout 360 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.