821 17th St
821 17th St is a 15-story building in Greater Downtown Denver with 98% of its floor area within daylight reach of a facade. This screen estimates 361 homes and scores it 87 out of 100 for office-to-residential conversion suitability.
CO-1 · Screened 2026-09-19 · Strong candidate
Also addressed as 860 18th St, 1726 Champa St, 1732 Champa St, 1742 Champa St and 1776 Champa St: Denver’s address records place all 6 on this one footprint.
Where 821 17th St is
Its block in Greater Downtown Denver, drawn from Denver's own building outlines and street centerlines.
- Already housing
- Not screened
- 821 17th St
This building does not pencil at default assumptions, even with a modeled RESIDE Act grant.
Across its 14 residential floors this building carries 7,972 sq ft of windowless core — area that must be gutted, re-plumbed and sprinklered but can never be rented as an apartment.
Part of this building is already homes. Denver's property records list 39 apartments here, alongside 1 non-residential record. 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 6 street addresses across 46,560 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 821 17th St, 2026-09-19.
| Suitability scoreStrong candidate | 87 / 100 |
|---|---|
| Storiesfrom 176 ft aerial-survey height ÷ 12 ft floor-to-floor | 15 |
| Height bandsfloor plate by floor range, from the city's roof outlines | Floors 1–3: 46,560 sq ft · Floor 4: 44,346 sq ft · Floor 5: 42,524 sq ft · Floors 6–7: 30,812 sq ft · Floor 8: 26,698 sq ft · Floor 9: 21,769 sq ft · Floor 10: 13,256 sq ft · Floor 11: 11,787 sq ft · Floor 12: 10,967 sq ft · Floors 13–14: 9,539 sq ft · Floor 15: 1,326 sq ft |
| Floor platetypical floor, from the city outlines | 46,560 sq ft |
| Daylight efficiencyshare within 35 ft of a facade | 98% |
| Deepest interior pointviability threshold is 80 ft | 51 ft |
| Windowless coretypical floor; the building-wide total is in the text above | 2,232 sq ft |
| Estimated homesat 750 sq ft average | 361 |
| Conversion cost$360/sq ft all-in on 346,495 sq ft | $124.7M |
| Gap before grantshortfall against completed value | $39.5M |
| Modeled RESIDE grantat the statutory per-award cap | $10.0M |
| BuiltDenver does not publish a construction year with this data | — |
| ZoningCBD | D-C |
| Opportunity Zonenot in a 2018 designated tract | No |
The plan: window line, shape and floor rhythm
42 ft of exterior wall for each home the screen estimates — enough for two- and three-bedroom homes across the plan.
The typical floor has 1,616 ft of exterior wall, and across 14 residential floors the building carries 15,184 ft of it in total, divided among the 361 homes this screen estimates.
Its plate is highly articulated at 0.22: a long, notched or wing-shaped outline with far more facade than its area needs — wasteful as an office envelope, and close to ideal for apartments. How window line and plate shape are measured.
At the model’s 750 sq ft average, the plan works out at about 25.8 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.
Why 821 17th St scores 87 out of 100
Daylight efficiency 100, Interior depth 73, Scale 100, Finance 61 — each out of 100, then weighted.
Score components for 821 17th St. Points are the subscore times its weight.
| Component | Subscore | Weight | Points |
|---|---|---|---|
| Daylight efficiency98% of the floor area within 35 ft of a facade, scored from 40% up to 90% | 100 | 45% | 45.0 |
| Interior depthdeepest interior point 51 ft from a facade, scored from 80 ft down to 40 ft | 73 | 25% | 18.3 |
| Scale361 estimated homes, scored from 0 up to 150 | 100 | 15% | 15.0 |
| Financeremaining gap is 24% of conversion cost, scored from 60% down to 0% | 61 | 15% | 9.1 |
Most of what it earns comes from daylight efficiency, and what holds it back most is finance, at 61 out of 100: remaining gap is 24% of conversion cost, scored from 60% down to 0%.
What the conversion would cost
$360 per square foot all-in across 346,495 sq ft of converted floor, or $124.7M in total — about $346K for each of the 361 homes.
All-in cost per square foot for 821 17th 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 7,972 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 361 homes is $85.2M.
What would have to be true
A $39.5M gap before any grant, $29.5M after the modeled one. The smallest single change that would close it: average unit size 26% down.
The shortfall before any grant is $39.5M. Closing it from the value side means each of the 361 homes finishing at $346K rather than the $236K the model assumes — 46% more. Closing it from the cost side means getting all-in cost down from $360 to $246 per square foot.
A modeled RESIDE grant of $10.0M moves that threshold to $318K a home. That is still above the $236K assumed, leaving $29.5M uncovered, which is why the grant does not unlock this one.
Nor do all four levers have to move. For 821 17th St, one alone would close the gap at:
Single-assumption flip points for 821 17th St, each holding the other three at their defaults.
| Average unit sizethe binding constraint — the least this building would need | 26% downto 556 sq ft |
|---|---|
| Conversion cost per square foot | 33% downto $175/sq ft |
| Completed value per home | 35% upto $318K |
All four are sliders in the survey, where 821 17th St re-scores against your own numbers.
How it compares in Greater Downtown Denver
821 17th St ranks 37th of the 214 buildings screened here, against a median score of 72.
Its floor plate is better lit than 88% of them, and shallower than 64% of them at its deepest interior point. On size it is the 57th 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 D-C zone
15th of 75 in CBD, 11th of 72 zoned D-C — the comparison that shares its rules, rents and streets.
Denver places 75 of the screened buildings in CBD. 821 17th St ranks 15th 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 51 ft, and together they would hold an estimated 33,698 homes. The group’s top scorer is 918 17th St, at 97.
72 of the screened buildings are zoned D-C. 821 17th St ranks 11th of them against a median score of 73. 39 score 70 or more, their median deepest interior point is 57 ft from a facade against this building’s 51 ft, and together they would hold an estimated 32,881 homes. The group’s top scorer is 721 19th St, at 95.
Its nearest match in size: 1989 16th St
The screened building closest to 821 17th St in converted floor area is 1989 16th St: 336,178 sq ft over 13 stories, against 346,495 sq ft over 15 here.
821 17th St scores 87 to its 59, and with the size held roughly equal most of that lead comes from daylight efficiency: 100 out of 100 here, 62 there (71% 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 3,800 ft apart.
The city's own study picked this building too
In August 2023 Denver and the architecture firm Gensler rated 21 downtown office buildings good candidates for conversion to housing and published the top 16 by address. One of them resolves to this building: “821 17th St”.
That is an outside opinion reached by different means — architects reading plans, not a model reading outlines — and this screen agrees with it: 821 17th St scores 87 out of 100 here, in the same top tier. The difference is the money rather than the geometry: at default assumptions the gap here is $39.5M, which no modeled RESIDE grant closes. A study asking whether a building can be converted and a model asking whether it would pencil are answering different questions.
Mile High CRE, Study Identifies 21 Downtown Denver Office Buildings as Good Candidates for Conversion. The full comparison across all 16 is on the Greater Downtown Denver page.
Would it qualify for a RESIDE Act grant?
The model awards 821 17th 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 821 17th St
The 4 closest the screen also covers, from 140 ft away. They are the colored outlines on the plan at the top of this page.
- 801 17th St12 stories · 73% daylit · 251 estimated homes · scores 60/100 (Worth a feasibility study)about 140 ft away
- 909 17th St14 stories · 88% daylit · 402 estimated homes · scores 76/100 (Strong candidate)about 200 ft away
- 999 17th St28 stories · 83% daylit · already an apartment buildingabout 340 ft away
- 717 17th St33 stories · 73% daylit · 593 estimated homes · scores 61/100 (Worth a feasibility study)about 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.