99 Chauncy St

Where 99 Chauncy St 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 660 ft of exterior wall, and across 10 residential floors the building carries 6,596 ft of it in total, divided among the 178 homes this screen estimates.

Its plate is moderately compact at 0.50: 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 17.8 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.

Why 99 Chauncy St scores 98 out of 100

Daylight efficiency 100, Interior depth 91, 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 91 out of 100: deepest interior point 44 ft from a facade, scored from 80 ft down to 40 ft.

Built in 1910

Boston records this building as going up in 1910, which puts it in the pre-1920 stock.

As a rule, the era that converts most readily: load-bearing masonry, small floor plates laid out before deep-plan offices were possible, operable windows and generous floor-to-floor heights. The usual obstacles are not daylight but hazardous materials, lifts and bringing structure up to current code. 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 97% daylight figure above deserves.

What the conversion would cost

$360 per square foot all-in across 172,491 sq ft of converted floor, or $62.1M in total — about $349K for each of the 178 homes.

That cost is charged across every converted square foot, including the 5,299 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 178 homes is $78.6M.

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 $62.1M of work with $16.5M to spare. Value per home would have to fall to $349K — 21% below the assumption — before the conversion stopped penciling, or all-in cost would have to rise from $360 to $456 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 99 Chauncy St:

All four are sliders in the survey, where 99 Chauncy St re-scores against your own numbers.

How it compares in Downtown Boston

99 Chauncy St ranks 9th of the 96 buildings screened here, against a median score of 89.

Its floor plate is better lit than 69% of them, and shallower than 61% of them at its deepest interior point. On size it is the 47th 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

5th of 52 zoned SKY — the comparison that shares its rules, rents and streets.

52 of the screened buildings are zoned SKY. 99 Chauncy St ranks 5th 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 44 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 99 Chauncy St in converted floor area is 15 New Chardon St: 176,950 sq ft over 12 stories, against 172,491 sq ft over 11 here.

99 Chauncy St scores 98 to its 79, and with the size held roughly equal most of that lead comes from interior depth: 91 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 3,200 ft apart.

Would it qualify for a RESIDE Act grant?

The model awards 99 Chauncy 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 99 Chauncy St

The 4 closest the screen also covers, from 160 ft away. They are the colored outlines on the plan at the top of this page.

• 62-74 Essex St
  8 stories · 96% daylit · 70 estimated homes · scores 90/100 (Strong candidate)
  about 160 ft away
• 11 Avenue De Lafayette
  6 stories · 99% daylit · 61 estimated homes · scores 91/100 (Strong candidate)
  about 180 ft away
• 588-622 Washington St
  8 stories · 53% daylit · 199 estimated homes · scores 35/100 (Marginal)
  about 250 ft away
• 1 Avenue De Lafayette
  22 stories · 59% daylit · 721 estimated homes · scores 35/100 (Marginal)
  about 350 ft away