801 15th St

801 15th St is a 19-story building in Greater Downtown Denver with 92% of its floor area within daylight reach of a facade. This screen estimates 213 homes and scores it 94 out of 100 for office-to-residential conversion suitability.

CO-1 · Screened 2026-10-04 · Strong candidate

Build a free conversion planCheck its numbers, lay out its homes and get a two-page PDF. Free.

Where 801 15th St is

Its block in Greater Downtown Denver, drawn from Denver's own building outlines and street centerlines.

Suitability score

0–29

30–49

50–69

70–100

Already housing
Not screened
801 15th St

801 15th St and the 1,000 ft of Greater Downtown Denver around it. The streets are drawn at the width of the right-of-way they run down, sidewalks included, and named, and every building on these blocks is drawn. What is left open and stippled is neither: a surface lot, a plaza or a vacant parcel. The screened buildings are colored by the ramp above, the same one the district map uses, carry their score, and each is a link to its own page. Each casts a shadow as long as its measured height lets it, so towers stand out from the low buildings around them; the unscreened buildings have no measured height and cast none. 801 15th St is outlined in its own score color at the outline it covers at ground level. Dashed inside it is the typical floor, the one the floor-plate figure below draws, because this building steps back as it rises. Its windowless core is hatched. The inset places it among every building the screen covers.

Typical floor plan: 92% of the building’s floor area sits within daylight reach of a facade; the drawing shows its typical floor, where the share is 100%. The shading is daylight, darkest at the windows and gone 35 ft in. The hatched area is windowless core: 30 sq ft per typical floor that must be renovated but can never be rented as an apartment. The dimension marks the deepest interior point, 37 ft from the nearest window. A–A is where the section beside it is cut.

Section A–A: cut across the depth of the plate, through the middle of the core. Daylight reaches 35 ft in from every facade, fading as it goes, and the hatched stripe left between the lit edges is floor that gets converted and can never be rented: 30 sq ft on the floor the screen scores, and 17,348 sq ft over 18 residential floors. The steps are where the building sets back as it rises. The shaded ground floor is converted like the rest and counted as no homes.

This building does not pencil at default assumptions, even with a modeled RESIDE Act grant.

Across its 18 residential floors this building carries 17,348 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 801 15th St, 2026-10-04.

Suitability scoreStrong candidate	94 / 100
Storiesfrom 232 ft aerial-survey height ÷ 12 ft floor-to-floor	19
Height bandsfloor plate by floor range, from the city's roof outlines	Floors 1–7: 15,266 sq ft · Floors 8–18: 11,262 sq ft · Floor 19: 2,288 sq ft
Floor platetypical floor, from the city outlines	11,262 sq ft
Daylight efficiencyshare within 35 ft of a facade	92%
Deepest interior pointviability threshold is 80 ft	37 ft
Windowless coretypical floor; the building-wide total is in the text above	30 sq ft
Estimated homesat 750 sq ft average	213
Conversion cost$360/sq ft all-in on 217,763 sq ft	$78.4M
Gap before grantshortfall against completed value	$28.1M
Modeled RESIDE grantat the statutory per-award cap	$10.0M
BuiltDenver does not publish a construction year with this data	—
ZoningCBD	D-TD
Opportunity Zonenot in a 2018 designated tract	No

The plan: window line, shape and floor rhythm

41 ft of exterior wall for each home the screen estimates — enough for two- and three-bedroom homes across the plan.

The typical floor has 500 ft of exterior wall, and across 18 residential floors the building carries 8,701 ft of it in total, divided among the 213 homes this screen estimates.

Its plate is moderately compact at 0.57: 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 11.8 homes per floor. Its floors are not alike, though: the typical floor's deepest interior point is 37 ft from a facade, while its worst floor reaches 61 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 801 15th St scores 94 out of 100

Daylight efficiency 100, Interior depth 100, Scale 100, Finance 61 — each out of 100, then weighted.

Score components for 801 15th St. Points are the subscore times its weight.

Component	Subscore	Weight	Points
Daylight efficiency92% of the floor area within 35 ft of a facade, scored from 40% up to 90%	100	45%	45.0
Interior depthdeepest interior point 37 ft from a facade, scored from 80 ft down to 40 ft	100	25%	25.0
Scale213 estimated homes, scored from 0 up to 150	100	15%	15.0
Financeremaining gap is 23% of conversion cost, scored from 60% down to 0%	61	15%	9.2

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 23% of conversion cost, scored from 60% down to 0%.

What the conversion would cost

$360 per square foot all-in across 217,763 sq ft of converted floor, or $78.4M in total — about $368K for each of the 213 homes.

All-in cost per square foot for 801 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 17,348 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 213 homes is $50.3M.

What would have to be true

A $28.1M gap before any grant, $18.1M after the modeled one. The smallest single change that would close it: average unit size 26% down.

The shortfall before any grant is $28.1M. Closing it from the value side means each of the 213 homes finishing at $368K rather than the $236K the model assumes — 56% more. Closing it from the cost side means getting all-in cost down from $360 to $231 per square foot.

A modeled RESIDE grant of $10.0M moves that threshold to $321K a home. That is still above the $236K assumed, leaving $18.1M uncovered, which is why the grant does not unlock this one.

Nor do all four levers have to move. For 801 15th St, one alone would close the gap at:

Single-assumption flip points for 801 15th St, each holding the other three at their defaults.

Average unit sizethe binding constraint — the least this building would need	26% downto 553 sq ft
Conversion cost per square foot	32% downto $177/sq ft
Completed value per home	36% upto $321K

All four are sliders in the survey, where 801 15th St re-scores against your own numbers.

How it compares in Greater Downtown Denver

801 15th St ranks 12th of the 208 buildings screened here, against a median score of 73.

Its floor plate is better lit than 81% of them, and shallower than 87% of them at its deepest interior point. On size it is the 105th largest by estimated homes. The full survey of all 208 buildings ranks and maps every one of them, and the list by address links each to its own page.

Within CBD and the D-TD zone

6th of 74 in CBD, 3rd of 20 zoned D-TD — the comparison that shares its rules, rents and streets.

Denver places 74 of the screened buildings in CBD. 801 15th St ranks 6th of them against a median score of 71. 38 score 70 or more, their median deepest interior point is 57 ft from a facade against this building’s 37 ft, and together they would hold an estimated 33,455 homes. The group’s top scorer is 918 17th St, at 97.

20 of the screened buildings are zoned D-TD. 801 15th St ranks 3rd of them against a median score of 69. 10 score 70 or more, their median deepest interior point is 57 ft from a facade against this building’s 37 ft, and together they would hold an estimated 8,565 homes. The group’s top scorer is 918 17th St, at 97.

Its nearest match in size: 1380 Lawrence St

The screened building closest to 801 15th St in converted floor area is 1380 Lawrence St: 201,355 sq ft over 16 stories, against 217,763 sq ft over 19 here.

801 15th St scores 94 to its 89, and with the size held roughly equal most of that lead comes from interior depth: 100 out of 100 here, 79 there (deepest interior point 48 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 1,400 ft apart.

Would it qualify for a RESIDE Act grant?

The model awards 801 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 801 15th St

The 4 closest the screen also covers, from 200 ft away. They are the colored outlines on the plan at the top of this page.

820 16th St
10 stories · 79% daylit · 180 estimated homes · scores 67/100 (Worth a feasibility study)
about 200 ft away
800 16th St
11 stories · 88% daylit · already an apartment building
about 210 ft away
800 15th St
7 stories · 100% daylit · 89 estimated homes · scores 91/100 (Strong candidate)
about 210 ft away
716 16th St
10 stories · 66% daylit · 194 estimated homes · scores 53/100 (Worth a feasibility study)
about 250 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.