1 Liberty Sq

Where 1 Liberty Sq is

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

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 480 ft of exterior wall, and across 12 residential floors the building carries 5,762 ft of it in total, divided among the 156 homes this screen estimates.

Its plate is compact at 0.79: close to a square or a circle, the most efficient envelope an office can have and the least generous one for apartments: little perimeter to divide among homes. How window line and plate shape are measured.

At the model’s 750 sq ft average, the plan works out at about 13.0 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.

Why 1 Liberty Sq scores 87 out of 100

Daylight efficiency 88, Interior depth 69, Scale 100, Finance 100 — each out of 100, then weighted.

Most of what it earns comes from daylight efficiency, and what holds it back most is interior depth, at 69 out of 100: deepest interior point 53 ft from a facade, scored from 80 ft down to 40 ft.

Built in 1924

Boston records this building as going up in 1924, which puts it in the interwar stock.

As a rule, steel or concrete frames with punched windows and plates still narrow enough for daylight to reach the middle, often with high ceilings. Among the most convertible stock there is, and the reason so many early conversions were of buildings this age. 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 174,969 sq ft of converted floor, or $63.0M in total — about $404K for each of the 156 homes.

That cost is charged across every converted square foot, including the 27,811 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 156 homes is $68.9M.

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 $63.0M of work with $5.9M to spare. Value per home would have to fall to $404K — 9% below the assumption — before the conversion stopped penciling, or all-in cost would have to rise from $360 to $394 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 1 Liberty Sq:

All four are sliders in the survey, where 1 Liberty Sq re-scores against your own numbers.

How it compares in Downtown Boston

1 Liberty Sq ranks 56th of the 96 buildings screened here, against a median score of 89.

Its floor plate is better lit than 43% of them, and shallower than 43% of them at its deepest interior point. On size it is the 51st 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.

Within the SKY zone

29th of 52 zoned SKY — the comparison that shares its rules, rents and streets.

52 of the screened buildings are zoned SKY. 1 Liberty Sq ranks 29th of them against a median score of 88. 40 score 70 or more, their median deepest interior point is 51 ft from a facade against this building’s 53 ft, and together they would hold an estimated 19,019 homes. The group’s top scorer is 147 Milk St, at 100.

Its nearest match in size: 15 New Chardon St

The screened building closest to 1 Liberty Sq in converted floor area is 15 New Chardon St: 176,950 sq ft over 12 stories, against 174,969 sq ft over 13 here.

1 Liberty Sq scores 87 to its 79, and with the size held roughly equal most of that lead comes from interior depth: 69 out of 100 here, 47 there (deepest interior point 61 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 2,500 ft apart.

Would it qualify for a RESIDE Act grant?

The model awards 1 Liberty Sq $9.4M, 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 1 Liberty Sq

The 4 closest the screen also covers, from 220 ft away. They are the colored outlines on the plan at the top of this page.

• 147 Milk St
  10 stories · 100% daylit · 259 estimated homes · scores 100/100 (Strong candidate)
  about 220 ft away
• 71-75 Kilby St
  13 stories · 89% daylit · 451 estimated homes · scores 84/100 (Strong candidate)
  about 220 ft away
• 15-19 Broad St
  33 stories · 68% daylit · 706 estimated homes · scores 35/100 (Marginal)
  about 360 ft away
• 260 Franklin St
  26 stories · 81% daylit · 358 estimated homes · scores 84/100 (Strong candidate)
  about 360 ft away