20 Rowes Whf
20 Rowes Whf is a 18-story building in Downtown Boston with 84% of its floor area within daylight reach of a facade. This screen estimates 643 homes and scores it 86 out of 100 for office-to-residential conversion suitability.
MA-7 & MA-8 · Screened 2026-10-04 · Strong candidate
Also addressed as 50 Rowes Whf: Boston’s address records place both on this one footprint.
Where 20 Rowes Whf is
Its block in Downtown Boston, drawn from Boston's own building outlines and street centerlines.
- Already housing, or excluded for residential records on a shared parcel
- Not screened
- 20 Rowes Whf
This building's conversion pencils at default assumptions without any subsidy.
Across its 17 residential floors this building carries 115,946 sq ft of windowless core — area that must be gutted, re-plumbed and sprinklered but can never be rented as an apartment.
Homes are recorded on a parcel this building shares. Boston's assessing records list 94 condominiums on a parcel it shares with other buildings, alongside 2 non-residential records. Which of those buildings has the homes is not recorded. The figures here treat the whole building as convertible, so read them as an upper bound and check whether any floors are already housing.
Modeled conversion metrics for 20 Rowes Whf, 2026-10-04.
| Suitability scoreStrong candidate | 86 / 100 |
|---|---|
| Storiesfrom 215 ft aerial-survey height ÷ 12 ft floor-to-floor | 18 |
| Height bandsfloor plate by floor range, from the city's roof outlines | Floors 1–3: 74,094 sq ft · Floor 4: 72,922 sq ft · Floors 5–6: 71,699 sq ft · Floor 7: 69,689 sq ft · Floor 8: 65,031 sq ft · Floor 9: 41,592 sq ft · Floor 10: 34,359 sq ft · Floor 11: 27,852 sq ft · Floors 12–13: 24,694 sq ft · Floors 14–16: 19,365 sq ft · Floor 17: 5,213 sq ft · Floor 18: 3,219 sq ft |
| Floor platetypical floor, from the city outlines | 74,094 sq ft |
| Daylight efficiencyshare within 35 ft of a facade | 84% |
| Deepest interior pointviability threshold is 80 ft | 54 ft |
| Windowless coretypical floor; the building-wide total is in the text above | 14,448 sq ft |
| Estimated homesat 750 sq ft average | 643 |
| Conversion cost$360/sq ft all-in on 718,946 sq ft | $258.8M |
| Gap before grantpencils unsubsidized | -$25.1M |
| Modeled RESIDE grantat the statutory per-award cap | $10.0M |
| BuiltBoston's own record of the construction year | 1987 |
| ZoningDowntown Boston | DOWNTOWN WATERFRONT SUBDISTRICT |
| Opportunity Zonenot in a 2018 designated tract | No |
The plan: window line, shape and floor rhythm
36 ft of exterior wall for each home the screen estimates — enough for two- and three-bedroom homes across the plan.
The typical floor has 2,045 ft of exterior wall, and across 17 residential floors the building carries 23,010 ft of it in total, divided among the 643 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 37.8 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.
Why 20 Rowes Whf scores 86 out of 100
Daylight efficiency 88, Interior depth 64, Scale 100, Finance 100 — each out of 100, then weighted.
Score components for 20 Rowes Whf. Points are the subscore times its weight.
| Component | Subscore | Weight | Points |
|---|---|---|---|
| Daylight efficiency84% of the floor area within 35 ft of a facade, scored from 40% up to 90% | 88 | 45% | 39.5 |
| Interior depthdeepest interior point 54 ft from a facade, scored from 80 ft down to 40 ft | 64 | 25% | 16.1 |
| Scale643 estimated homes, scored from 0 up to 150 | 100 | 15% | 15.0 |
| Financecompleted value covers conversion cost with 14% to spare, which tops out the component | 100 | 15% | 15.0 |
Most of what it earns comes from daylight efficiency, and what holds it back most is interior depth, at 64 out of 100: deepest interior point 54 ft from a facade, scored from 80 ft down to 40 ft.
Built in 1987
Boston records this building as going up in 1987, which puts it in the late-modern stock.
As a rule, typically the hardest to convert: the deepest plates of any era, large central cores, and floor-to-floor heights tight enough that running residential drainage under a ceiling can be the thing that ends a project. That is the era’s general tendency rather than a finding about this building — the model reads an outline and a height, and can see nothing inside — but it is the first thing an architect would want to know, and it colours how much confidence the 84% daylight figure above deserves.
What the conversion would cost
$360 per square foot all-in across 718,946 sq ft of converted floor, or $258.8M in total — about $403K for each of the 643 homes.
All-in cost per square foot for 20 Rowes Whf: 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 115,946 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 $442K a home, which for 643 homes is $283.9M.
What would have to be true
This one already clears the bar. The question is how much room it has before it stops.
At $442K a home, completed value covers the $258.8M of work with $25.1M to spare. Value per home would have to fall to $403K — 9% below the assumption — before the conversion stopped penciling, or all-in cost would have to rise from $360 to $395 per square foot. Neither is a wide margin in a market that moves, but this building does not need a grant to work.
Each of these, moved on its own, would be enough to undo that for 20 Rowes Whf:
Single-assumption flip points for 20 Rowes Whf, each holding the other three at their defaults.
| Circulation efficiencythe binding constraint — the least this building would need | 12% downto 70% |
|---|---|
| Completed value per home | 12% downto $387K |
| Average unit size | 14% upto 855 sq ft |
| Conversion cost per square foot | 19% upto $309/sq ft |
All four are sliders in the survey, where 20 Rowes Whf re-scores against your own numbers.
How it compares in Downtown Boston
20 Rowes Whf ranks 57th of the 96 buildings screened here, against a median score of 89.
Its floor plate is better lit than 42% of them, and shallower than 38% of them at its deepest interior point. On size it is the 16th largest by estimated homes. The full survey of all 96 buildings ranks and maps every one of them, and the list by address links each to its own page.
Its nearest match in size: 200 State St
The screened building closest to 20 Rowes Whf in converted floor area is 200 State St: 642,469 sq ft over 18 stories, against 718,946 sq ft over 18 here.
20 Rowes Whf scores 86 to its 75, and with the size held roughly equal most of that lead comes from interior depth: 64 out of 100 here, 37 there (deepest interior point 65 ft from a facade, scored from 80 ft down to 40 ft). On the money they sit in the same place: each pencils without a subsidy. The two stand about 1,500 ft apart.
Would it qualify for a RESIDE Act grant?
The model awards 20 Rowes Whf $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 20 Rowes Whf
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.
- 40 Rowes Whf9 stories · 96% daylit · excluded: residential records on a shared parcelabout 140 ft away
- 390-400R Atlantic Ave7 stories · 79% daylit · 85 estimated homes · scores 71/100 (Strong candidate)about 360 ft away
- 90 Oliver St45 stories · 76% daylit · 743 estimated homes · scores 70/100 (Strong candidate)about 590 ft away
- 150 Oliver St50 stories · 80% daylit · 986 estimated homes · scores 70/100 (Worth a feasibility study)about 640 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.