15 New Chardon St

Where 15 New Chardon 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

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

The typical floor has 531 ft of exterior wall, and across 11 residential floors the building carries 5,859 ft of it in total, divided among the 154 homes this screen estimates.

Its plate is compact at 0.73: 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 14.0 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.

Why 15 New Chardon St scores 79 out of 100

Daylight efficiency 83, Interior depth 47, 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 47 out of 100: deepest interior point 61 ft from a facade, scored from 80 ft down to 40 ft.

Built in 1968

Boston records this building as going up in 1968, which puts it in the post-war stock.

As a rule, the period when plates got deep and facades became curtain wall: sealed glazing, lower floor-to-floor heights, and mechanical systems designed around a sealed box. Conversions here usually turn on whether the windows can be made to open and whether ceilings survive new plumbing. 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 82% daylight figure above deserves.

What the conversion would cost

$360 per square foot all-in across 176,950 sq ft of converted floor, or $63.7M in total — about $414K for each of the 154 homes.

That cost is charged across every converted square foot, including the 32,535 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 154 homes is $68.0M.

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 $63.7M of work with $4.3M to spare. Value per home would have to fall to $414K — 6% below the assumption — before the conversion stopped penciling, or all-in cost would have to rise from $360 to $384 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 15 New Chardon St:

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

How it compares in Downtown Boston

15 New Chardon St ranks 67th of the 96 buildings screened here, against a median score of 89.

Its floor plate is better lit than 33% of them, and shallower than 27% of them at its deepest interior point. On size it is the 52nd 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 PEMBERTON SQUARE PROTECTION AREA zone

4th of 7 zoned PEMBERTON SQUARE PROTECTION AREA — the comparison that shares its rules, rents and streets.

7 of the screened buildings are zoned PEMBERTON SQUARE PROTECTION AREA. 15 New Chardon St ranks 4th of them against a median score of 79. 5 score 70 or more, their median deepest interior point is 60 ft from a facade against this building’s 61 ft, and together they would hold an estimated 2,645 homes. The group’s top scorer is 6-6B Beacon St, at 94.

Its nearest match in size: 1 Liberty Sq

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

15 New Chardon St scores 79 to its 87, and with the size held roughly equal most of that shortfall comes from interior depth: 47 out of 100 here, 69 there (deepest interior point 53 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 15 New Chardon St $9.2M, 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 15 New Chardon 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.

• 25 New Chardon St
  7 stories · 78% daylit · 87 estimated homes · scores 67/100 (Worth a feasibility study)
  about 160 ft away
• 14 Bowdoin St
  25 stories · 75% daylit · 633 estimated homes · scores 74/100 (Strong candidate)
  about 440 ft away
• 100-110 Sudbury St
  46 stories · 90% daylit · excluded: residential records on a shared parcel
  about 700 ft away
• 2 Congress St
  10 stories · 48% daylit · excluded: residential records on a shared parcel
  about 880 ft away