480 E 20th Ave
480 E 20th Ave is a 6-story building in Greater Downtown Denver with 95% of its floor area within daylight reach of a facade. This screen estimates 189 homes and scores it 93 out of 100 for office-to-residential conversion suitability.
CO-1 · Screened 2026-09-19 · Strong candidate
Also addressed as 490 E 20th Ave, 1909 N Pennsylvania St, 1935 N Pennsylvania St, 1945 N Pennsylvania St, 1955 N Pennsylvania St, 1971 N Pennsylvania St, 1985 N Pennsylvania St, 1989 N Pennsylvania St, 1995 N Pennsylvania St and 1999 N Pennsylvania St: Denver’s address records place all 11 on this one footprint.
Where 480 E 20th Ave is
Its block in Greater Downtown Denver, drawn from Denver's own building outlines and street centerlines.
- Already housing
- Not screened
- 480 E 20th Ave
This building does not pencil at default assumptions, even with a modeled RESIDE Act grant.
Every floor carries 2,055 sq ft of windowless core — area that must be gutted, re-plumbed and sprinklered but can never be rented as an apartment. Across 5 residential floors that is 10,275 sq ft of cost carrying no revenue.
Modeled conversion metrics for 480 E 20th Ave, 2026-09-19.
| Suitability scoreStrong candidate | 93 / 100 |
|---|---|
| Storiesfrom 66 ft aerial-survey height ÷ 12 ft floor-to-floor | 6 |
| Floor plateper floor, from the city footprint | 37,513 sq ft |
| Daylight efficiencyshare within 35 ft of a facade | 95% |
| Deepest interior pointviability threshold is 80 ft | 44 ft |
| Windowless coreper floor — renovated but never rentable | 2,055 sq ft |
| Estimated homesat 750 sq ft average | 189 |
| Conversion cost$360/sq ft all-in on 187,566 sq ft | $67.5M |
| Gap before grantshortfall against completed value | $22.9M |
| Modeled RESIDE grantat the statutory per-award cap | $10.0M |
| BuiltDenver does not publish a construction year with this data | — |
| ZoningNorth Capitol Hill | R-4-X |
| Opportunity Zonenot in a 2018 designated tract | No |
The plan: window line, shape and floor rhythm
33 ft of exterior wall for each home the screen estimates — enough for two- and three-bedroom homes across the plan.
The typical floor has 1,232 ft of exterior wall, and across 5 residential floors the building carries 6,160 ft of it in total, divided among the 189 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 37.8 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.
Why 480 E 20th Ave scores 93 out of 100
Daylight efficiency 100, Interior depth 90, Scale 100, Finance 68 — each out of 100, then weighted.
Score components for 480 E 20th Ave. Points are the subscore times its weight.
| Component | Subscore | Weight | Points |
|---|---|---|---|
| Daylight efficiency95% of the floor area within 35 ft of a facade, scored from 40% up to 90% | 100 | 45% | 45.0 |
| Interior depthdeepest interior point 44 ft from a facade, scored from 80 ft down to 40 ft | 90 | 25% | 22.6 |
| Scale189 estimated homes, scored from 0 up to 150 | 100 | 15% | 15.0 |
| Financeremaining gap is 19% of conversion cost, scored from 60% down to 0% | 68 | 15% | 10.2 |
Most of what it earns comes from daylight efficiency, and what holds it back most is finance, at 68 out of 100: remaining gap is 19% of conversion cost, scored from 60% down to 0%.
What the conversion would cost
$360 per square foot all-in across 187,566 sq ft of converted floor, or $67.5M in total — about $357K for each of the 189 homes.
All-in cost per square foot for 480 E 20th Ave: 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 10,275 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 189 homes is $44.6M.
What would have to be true
A $22.9M gap before any grant, $12.9M after the modeled one. The smallest single change that would close it: average unit size 22% down.
The shortfall before any grant is $22.9M. Closing it from the value side means each of the 189 homes finishing at $357K rather than the $236K the model assumes — 51% more. Closing it from the cost side means getting all-in cost down from $360 to $238 per square foot.
A modeled RESIDE grant of $10.0M moves that threshold to $304K a home. That is still above the $236K assumed, leaving $12.9M uncovered, which is why the grant does not unlock this one.
Nor do all four levers have to move. For 480 E 20th Ave, one alone would close the gap at:
Single-assumption flip points for 480 E 20th Ave, each holding the other three at their defaults.
| Average unit sizethe binding constraint — the least this building would need | 22% downto 581 sq ft |
|---|---|
| Conversion cost per square foot | 26% downto $191/sq ft |
| Completed value per home | 29% upto $304K |
All four are sliders in the survey, where 480 E 20th Ave re-scores against your own numbers.
How it compares in Greater Downtown Denver
480 E 20th Ave ranks 14th of the 214 buildings screened here, against a median score of 72.
Its floor plate is better lit than 84% of them, and shallower than 76% of them at its deepest interior point. On size it is the 111th 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 North Capitol Hill and the R-4-X zone
5th of 41 in North Capitol Hill, 2nd of 4 zoned R-4-X — the comparison that shares its rules, rents and streets.
Denver places 41 of the screened buildings in North Capitol Hill. 480 E 20th Ave ranks 5th of them against a median score of 85. 32 score 70 or more, their median deepest interior point is 47 ft from a facade against this building’s 44 ft, and together they would hold an estimated 8,820 homes. The group’s top scorer is 1776 N Grant St, at 97.
4 of the screened buildings are zoned R-4-X. 480 E 20th Ave ranks 2nd of them against a median score of 90. 3 score 70 or more, their median deepest interior point is 43 ft from a facade against this building’s 44 ft, and together they would hold an estimated 717 homes. The group’s top scorer is 500 E 19th Ave, at 95.
Its nearest match in size: 1600 17th St
The screened building closest to 480 E 20th Ave in converted floor area is 1600 17th St: 183,452 sq ft over 7 stories, against 187,566 sq ft over 6 here.
The two land within a few points of each other — 93 here, 95 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 5,400 ft apart.
Would it qualify for a RESIDE Act grant?
The model awards 480 E 20th Ave $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 480 E 20th Ave
The 4 closest the screen also covers, from 150 ft away. They are the colored outlines on the plan at the top of this page.
- 1950 N Logan St13 stories · 96% daylit · already a condominium buildingabout 150 ft away
- 530 E 20th Ave7 stories · 100% daylit · 59 estimated homes · scores 88/100 (Strong candidate)about 310 ft away
- 1915 N Logan St11 stories · 83% daylit · already an apartment buildingabout 350 ft away
- 400 E 19th Ave6 stories · 100% daylit · 76 estimated homes · scores 89/100 (Strong candidate)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.