185 Franklin St

Where 185 Franklin 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

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

The typical floor has 1,029 ft of exterior wall, and across 28 residential floors the building carries 19,924 ft of it in total, divided among the 584 homes this screen estimates.

Its plate is moderately compact at 0.70: 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 20.9 homes per floor, repeated on every residential floor, since this building's outline does not change as it rises.

Why 185 Franklin St scores 35 out of 100

The weighted components add to 36, but the score is capped at 35 because its deepest interior point is 94 ft from a facade, past the 80 ft threshold beyond which conversion requires carving a light well.

Most of what it earns comes from scale, and what holds it back most is interior depth, at 0 out of 100: deepest interior point 94 ft from a facade, scored from 80 ft down to 40 ft.

Built in 1948

Boston records this building as going up in 1948, 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 54% daylight figure above deserves.

What the conversion would cost

$360 per square foot all-in across 1,007,277 sq ft of converted floor, or $362.6M in total — about $621K for each of the 584 homes.

That cost is charged across every converted square foot, including the 458,959 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 584 homes is $257.8M.

What would have to be true

A $104.8M gap before any grant, $94.8M after the modeled one. The smallest single change that would close it: average unit size 27% down.

The shortfall before any grant is $104.8M. Closing it from the value side means each of the 584 homes finishing at $621K rather than the $442K the model assumes — 41% more. Closing it from the cost side means getting all-in cost down from $360 to $256 per square foot.

A modeled RESIDE grant of $10.0M moves that threshold to $604K a home. That is still above the $442K assumed, leaving $94.8M uncovered, which is why the grant does not unlock this one.

Nor do all four levers have to move. For 185 Franklin St, one alone would close the gap at:

All four are sliders in the survey, where 185 Franklin St re-scores against your own numbers.

How it compares in Downtown Boston

185 Franklin St ranks 90th of the 96 buildings screened here, against a median score of 89.

Its floor plate is better lit than 3% of them, and shallower than 6% of them at its deepest interior point. On size it is the 22nd 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

47th of 52 zoned SKY — the comparison that shares its rules, rents and streets.

52 of the screened buildings are zoned SKY. 185 Franklin St ranks 47th 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 94 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: 15-19 Broad St

The screened building closest to 185 Franklin St in converted floor area is 15-19 Broad St: 971,397 sq ft over 33 stories, against 1,007,277 sq ft over 29 here.

The two land within a few points of each other — 35 here, 35 there — so at this size the screen reads them as much the same prospect. On the money they sit in the same place: each falls short even with the modeled grant. The two stand about 1,200 ft apart.

Would it qualify for a RESIDE Act grant?

The model awards 185 Franklin 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 185 Franklin St

The 4 closest the screen also covers, from 310 ft away. They are the colored outlines on the plan at the top of this page.

• 225 Franklin St
  40 stories · 75% daylit · 722 estimated homes · scores 80/100 (Strong candidate)
  about 310 ft away
• 100 Federal St
  50 stories · 62% daylit · 1,164 estimated homes · scores 35/100 (Marginal)
  about 330 ft away
• 218-230 Congress St
  12 stories · 82% daylit · 202 estimated homes · scores 85/100 (Strong candidate)
  about 350 ft away
• 207-211 Congress St
  32 stories · 82% daylit · 550 estimated homes · scores 84/100 (Strong candidate)
  about 370 ft away