Cambridge Civic Journal Forum

February 16, 2021

Cambridge InsideOut Episodes 491-492: February 16, 2021

Episode 491 – Cambridge InsideOut: Feb 16, 2021 (Part 1)

This episode was broadcast on Feb 16, 2021 at 6:00pm. Topics: Impeachment and acquittal; redefinition of major parties; Red Sox; Covid update; observations on density and the “missing middle” petition; loosening of single-family zoning. Hosts: Judy Nathans, Robert Winters [On YouTube] [audio]


Episode 492 – Cambridge InsideOut: Feb 16, 2021 (Part 2)

This episode was broadcast on Feb 16, 2021 at 6:30pm. Topics: In search of a Superintendent of Schools and the mythical visionary; eduspeak; young socialist robots invade public comment; democracy by the pound; SROs – an idea whose time may have come again; organically grown local politics. Hosts: Judy Nathans, Robert Winters [On YouTube] [audio]

[Materials used in these episodes]

A few observations on density

Filed under: Cambridge,planning — Tags: , , , , , — Robert Winters @ 12:44 pm

A few observations on density

Feb 16, 2021 (w/Feb 17 addition of S. Normandy Ave.) – Several years ago I was thinking about the past, present, and future of Central Square and decided to simply take a walk through the Square with a camera with as objective an eye as I could manage. The result of that walk was something I called "Completing the Square" – a little math joke tied to the main observation that regardless of any opinions about how tall or dense Central Square may be or should be, there were lots of missing teeth and locations which could be improved by the presence of some new or enhanced buildings. That was before the new Mass & Main complex (now Market Central) was built.

In a similar vein, a couple of days ago I had the notion to do something of a virtual walk (in my head) along some streets with which I am quite familiar just to imagine how they might change under the proposed "Missing Middle Housing" zoning proposal. In my opinion, most of these streets function pretty well as they are and many of them (in particular those now zoned as Res C-1) would be considered pretty dense by any reasonable standard. I downloaded the City’s Assessors Database (thank you Open Data Portal!) and painstakingly reassembled all the living area information from the many condominiums in order to recreate the total living area to go with the total land area for each respective lot. (This was like reassembling puzzle pieces in some cases.) I then calculated the FAR (floor-area-ratio) for all lots on 28 representative streets (somewhat alphabetically biased as I went through them).

Prior to calculating some statistics on each of these streets I decided to exclude a few anomalies such as parks (no housing will be going there under any zoning revisions), municipal parking lots, City buildings (like City Hall, the Annex, DPW, etc.) as well as some lots that are in zoning districts unaffected by the proposed "Missing Middle Housing" zoning proposal, e.g. the Central Square BB district.
[You can view the data for each of these streets here.]

The summary sheet is below. Since there are already some nonconforming lots with FAR even greater than what is proposed in the petition, the increases noted below actually understate the increases under full build-out. On the other hand, it’s not likely that anything close to full build-out would happen any time soon (if the petition were to prevail), so this should be viewed more as a measure of what could eventually happen as opposed to what will happen in the near future.

Note that even a relatively dense C-1 street like Cherry Street in The Port could see a 66% increase in density. Chalk Street (Res C) could see a 72% increase. Cornelius Way could have a 175% increase (that’s 2.75 times the current density). Near me, Antrim Street could go up 47%, Maple Ave. could go up 84%, and Lee Street could go up 50%. In the leafy western "suburbs", a Res B street like Appleton St. could go up 137% (2.37 times the current density) and Lakeview Ave. (a mix of Res A-1 and Res B) would nearly triple in density. In contrast, Berkshire St. in Wellington-Harrington might only rise 2%, so I suppose this is the ideal street by the "Missing Middle" standard.

It’s also worth noting that there’s really nothing in the petition that would in any way ensure that the chief beneficiaries would be middle class residents. The petition is primarily a vehicle for increasing densities and this could just as easily translate into larger homes for those who can afford them or the freedom to add on significant additions to existing homes. In other words, the "middle" part of the "missing middle" petition is missing.- RW

Street zoning on street total
land area
total
living area
gross
FAR
median
FAR
max
FAR
min
FAR
MM
factor
MM
increase
Amory St. C-1 166187 146798 0.88 0.89 2.25 0.00 1.40 40%
Andrew St. C-1 39671 36841 0.93 0.94 1.46 0.44 1.33 33%
Antrim St. C-1 215140 182351 0.85 0.85 1.59 0.45 1.47 47%
Appleton St. B 362349 167623 0.46 0.53 1.11 0.00 2.37 137%
Arlington St. A-2,B,C-2 162551 82694 0.51 0.51 0.94 0.31 2.45 145%
Avon Hill St. A-2,B 159726 86824 0.54 0.64 1.04 0.25 1.95 95%
Bellis Circle B,C-1A 134257 86705 0.65 0.69 1.24 0.36 1.80 80%
Berkeley St. & Pl. A-2 335663 147702 0.44 0.44 1.08 0.18 2.87 187%
Berkshire St. & Pl. C-1 142900 162073 1.13 1.22 2.42 0.00 1.02 2%
Bigelow St. C-1 98544 99178 1.68 0.99 2.48 0.55 1.27 27%
Bristol St. C-1 105743 98448 0.93 0.89 2.09 0.34 1.40 40%
Brookline St. B,C,BA-1,C-1,BB,SD9 462788 420848 0.91 0.88 2.59 0.00 1.41 41%
Buena Vista Pk. C-1 58147 42787 0.74 0.75 1.05 0.46 1.67 67%
Centre St. C-1 112030 118881 1.06 0.86 1.81 0.58 1.46 46%
Chalk St. C-1 59707 40178 0.67 0.73 1.35 0.30 1.72 72%
Chatham St. C-1 45415 43055 0.95 0.87 1.73 0.61 1.44 44%
Cherry St. C-1 140624 83033 0.59 0.75 1.26 0.00 1.66 66%
Columbia St. C1,BA,BB-CSQ 419529 435148 1.04 1.01 3.33 0.00 1.24 24%
Coolidge Hill Rd. A-2,A-1 155629 65633 0.42 0.55 1.85 0.00 2.26 126%
Cornelius Way C-1 67640 31196 0.46 0.45 0.83 0.30 2.75 175%
Dudley St. B 162444 135259 0.83 0.83 1.48 0.24 1.51 51%
Hurley St. C-1 185549 196004 1.06 1.09 2.45 0.42 1.15 15%
Inman St. C-1 386571 347610 0.90 0.88 2.36 0.34 1.41 41%
Lakeview Ave. A-1,B 717287 299854 0.42 0.42 1.07 0.15 2.99 199%
Lee St. C-1 184726 167663 0.91 0.83 2.17 0.48 1.50 50%
Maple Ave. B,C-1 198500 132455 0.67 0.68 1.57 0.36 1.84 84%
Norfolk St. C-1,B,BA 445240 445634 1.00 0.88 3.31 0.00 1.41 41%
Pleasant St. C,C-1,BA-3 387351 425992 1.10 0.93 2.27 0.36 1.34 34%
S. Normandy Ave. B 69538 24909 0.36 0.38 0.51 0.19 3.26 226%
all sample streets   6181446 4753376 0.77          

gross FAR = total living area divided by total land area
median FAR = median FAR of all lots on the street
max FAR = largest FAR for all lots on the street
min FAR = smallest FAR for all lots on the street (note that there may be vacant lots with FAR of 0)
MM factor = ratio of proposed "Missing Middle" FAR of 1.25 to current median FAR for street
MM increase = percent increase in FAR from current median FAR under full build-out

FAR-MMcalculations

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