650 15th St
650 15th St is a 37-story building in Greater Downtown Denver with 71% of its floor area within daylight reach of a facade. This screen estimates 814 homes and scores it 71 out of 100 for office-to-residential conversion suitability.
CO-1 · Screened 2026-09-19 · Strong candidate
Where 650 15th St is
Its block in Greater Downtown Denver, drawn from Denver's own building outlines and street centerlines.
- Already housing
- Not screened
- 650 15th St
This building does not pencil at default assumptions, even with a modeled RESIDE Act grant.
Across its 36 residential floors this building carries 314,698 sq ft of windowless core — area that must be gutted, re-plumbed and sprinklered but can never be rented as an apartment.
Modeled conversion metrics for 650 15th St, 2026-09-19.
| Suitability scoreStrong candidate | 71 / 100 |
|---|---|
| Storiesfrom 439 ft aerial-survey height ÷ 12 ft floor-to-floor | 37 |
| Height bandsfloor plate by floor range, from the city's roof outlines | Floors 1–6: 104,237 sq ft · Floor 7: 33,273 sq ft · Floors 8–24: 24,776 sq ft · Floor 25: 14,562 sq ft · Floors 26–31: 13,176 sq ft · Floor 32: 3,751 sq ft · Floor 33: 2,699 sq ft · Floors 34–37: 594 sq ft |
| Floor platetypical floor, from the city outlines | 24,776 sq ft |
| Daylight efficiencyshare within 35 ft of a facade | 71% |
| Deepest interior pointviability threshold is 80 ft | 39 ft |
| Windowless coretypical floor; the building-wide total is in the text above | 176 sq ft |
| Estimated homesat 750 sq ft average | 814 |
| Conversion cost$360/sq ft all-in on 1,078,102 sq ft | $388.1M |
| Gap before grantshortfall against completed value | $196.0M |
| Modeled RESIDE grantat the statutory per-award cap | $10.0M |
| BuiltDenver does not publish a construction year with this data | — |
| ZoningCBD | PUD |
| Opportunity Zonenot in a 2018 designated tract | No |
The plan: window line, shape and floor rhythm
37 ft of exterior wall for each home the screen estimates — enough for two- and three-bedroom homes across the plan.
The typical floor has 924 ft of exterior wall, and across 36 residential floors the building carries 29,801 ft of it in total, divided among the 814 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 22.6 homes per floor. Its floors are not alike, though: the typical floor's deepest interior point is 39 ft from a facade, while its worst floor reaches 133 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 650 15th St scores 71 out of 100
Daylight efficiency 62, Interior depth 100, Scale 100, Finance 20 — each out of 100, then weighted.
Score components for 650 15th St. Points are the subscore times its weight.
| Component | Subscore | Weight | Points |
|---|---|---|---|
| Daylight efficiency71% of the floor area within 35 ft of a facade, scored from 40% up to 90% | 62 | 45% | 27.7 |
| Interior depthdeepest interior point 39 ft from a facade, scored from 80 ft down to 40 ft | 100 | 25% | 25.0 |
| Scale814 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% | 20 | 15% | 3.0 |
Most of what it earns comes from daylight efficiency, and what holds it back most is finance, at 20 out of 100: remaining gap is 48% of conversion cost, scored from 60% down to 0%.
What the conversion would cost
$360 per square foot all-in across 1,078,102 sq ft of converted floor, or $388.1M in total — about $477K for each of the 814 homes.
All-in cost per square foot for 650 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 314,698 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 814 homes is $192.1M.
What would have to be true
A $196.0M gap before any grant, $186.0M after the modeled one. The smallest single change that would close it: average unit size 49% down.
The shortfall before any grant is $196.0M. Closing it from the value side means each of the 814 homes finishing at $477K rather than the $236K the model assumes — 102% more. Closing it from the cost side means getting all-in cost down from $360 to $178 per square foot.
A modeled RESIDE grant of $10.0M moves that threshold to $465K a home. That is still above the $236K assumed, leaving $186.0M uncovered, which is why the grant does not unlock this one.
Nor do all four levers have to move. For 650 15th St, one alone would close the gap at:
Single-assumption flip points for 650 15th St, each holding the other three at their defaults.
| Average unit sizethe binding constraint — the least this building would need | 49% downto 381 sq ft |
|---|---|
| Conversion cost per square foot | 66% downto $87/sq ft |
| Completed value per home | 97% upto $465K |
All four are sliders in the survey, where 650 15th St re-scores against your own numbers.
How it compares in Greater Downtown Denver
650 15th St ranks 113th of the 214 buildings screened here, against a median score of 72.
Its floor plate is better lit than 15% of them, and shallower than 85% of them at its deepest interior point. On size it is the 18th 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 CBD and the PUD zone
39th of 75 in CBD, 12th of 21 zoned PUD — the comparison that shares its rules, rents and streets.
Denver places 75 of the screened buildings in CBD. 650 15th St ranks 39th of them against a median score of 71. 40 score 70 or more, their median deepest interior point is 56 ft from a facade against this building’s 39 ft, and together they would hold an estimated 33,698 homes. The group’s top scorer is 918 17th St, at 97.
21 of the screened buildings are zoned PUD. 650 15th St ranks 12th of them against a median score of 77. 12 score 70 or more, their median deepest interior point is 49 ft from a facade against this building’s 39 ft, and together they would hold an estimated 5,808 homes. The group’s top scorer is 300 E 17th Ave, at 96.
Its nearest match in size: 25 E 16th Ave
The screened building closest to 650 15th St in converted floor area is 25 E 16th Ave: 1,053,163 sq ft over 38 stories, against 1,078,102 sq ft over 37 here.
650 15th St scores 71 to its 63, and with the size held roughly equal most of that lead comes from interior depth: 100 out of 100 here, 59 there (deepest interior point 56 ft from a facade, scored from 80 ft down to 40 ft). 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 650 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 650 15th St
The 4 closest the screen also covers, from 290 ft away. They are the colored outlines on the plan at the top of this page.
- 550 15th St17 stories · 78% daylit · 253 estimated homes · scores 70/100 (Worth a feasibility study)about 290 ft away
- 1400 Welton St11 stories · 84% daylit · 145 estimated homes · scores 75/100 (Strong candidate)about 290 ft away
- 750 15th St20 stories · 91% daylit · 251 estimated homes · scores 94/100 (Strong candidate)about 300 ft away
- 675 15th St38 stories · 58% daylit · 1,009 estimated homes · scores 32/100 (Marginal)about 380 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.