Density and the Data: How MMH will impact Cambridge

3/27/2021

Maple Avenue Cambridge Mar. 20, 2020 GBH by Philip Martin.

Mathematician, Robert Winters has written an important February 16, 2021 post on residential density in the Cambridge Civic Journal. Winters notes 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." Winters published the chart below of typical streets, what residential density they share now, and what density is being proposed for them in the Missing Middle Housing Petition, should it pass.

Maple Avenue, pictured above, which is in Mid-Cambridge (B and C-1 zones) is already very dense, with lots of existing MMH housing types. This street currently has a median FAR of .68, that could increase a staggering 84% if the MMH passes.

Antrim Street, pictured at the top of the CCC blog tab, also is in Mid-Cambridge (C-1). This street has a median FAR of .85. If the MMH passes, it could increase 47%. - between 1/2 and 2/3 larger than currently.

Any of the single- or multi-family houses on this street could be demolished and a larger structure 40 feet (4 story equivalent) could be built in its place.

For other Cambridge streets in our various neighborhoods, see his chart below. To determine the density increase proposed for your own home or that of your neighbors, we provide the formula below.

Curious what you will find? Check it out near the bottom of this post!

If a residence is larger than the allowable current FAR nothing is illegal. This just means the area was at one point down zoned after a certain optimum density had been reached.

What changes will MMH bring to your neighborhood? With MMH, every residence in the city would be up zoned to 1.25 FAR, larger than almost all structures in Cambridge residential areas today.

The two houses below offer important insights.

The single family East Cambridge house on the left is in the C-1 area (a home well known for its backyard “neighborhood farm”) is now zoned for 3 units. Under the MMH, but an investor could buy it, demolish this home and replace it with a large 40 foot tall modern box-style building for 13 small studio apartments (3 affordable with inclusionary. More likely there would be only 9 units created (and zero affordable to avoid Inclusionary impacts), each renting for c. $3,000 a month (not the kind of housing middle-income residents are looking for. The number of people living on this one property in an already very dense neighborhood would increase vastly. Nearby luxury town houses are beginning to appear. Bold contemporary style homes can be great if designed well, but these will likely increase the cost of housing in this neighborhood, and we would lose both this wonderful older home and its adjacent neighborhood farm.

A single family Mid-Cambridge home with a garage was recently purchased by a developer after the owner passed. This house was built as a 1 family but was converted to a 3 family about 50 years ago. Their garage is being replaced with a new infill single family market-rate (luxury) residence (see rendering on the right), built in a contemporary box-style, whose design reflects nothing of the neighboring homes. With MMH the height of the structure (now about 25 feet) could increase to 40 feet (nearly double) and without the cornice detail separating the second story from the third, mansard roof. The new structure would dwarf those around it and would be even more out of keeping with the housing fabric of nearby residences.

House in East Cambridge House in Mid-Cambridge with an Auxiliary home behind it.

How do you find the density of your own (or your neighbor's) home currently and how much it can be increased with the MMH ? Here is how you can find out what would happen to your residence or more importantly that of your neighbor, were it to be purchased, demolished, and rebuilt under MMH by an investor.

Here is what would happen to your residence or more importantly that of your neighbor, were it to be purchased, demolished, and rebuilt under MMH by an investor.

How to determine the FAR of any Cambridge residence in 3 easy steps – and how that will change

Look up the street address on the City Property Database: https://www.cambridgema.gov/PropertyDatabase
At the top of each file you will see the zoning district in which the property sits: Each has a different allowable FAR: A1, A2 and B have .5 FAR; C is .60; C1 is.75; C1A is 1.25.
At the bottom of every file, one sees BOTH the property’s total gross area and total living area. Simply divide the livable area of the home by the gross land area of the property. The result is the FAR for that property.

What are the core proposed changes in the MMH:

The last change would encourage large flat-roofed box-like structures in every neighborhood whether or not they fit with the homes that already exist there.

While we all want more affordable housing in Cambridge, the MMH would let investors and developers buy up property throughout the city, or add additional structures to it or in the back yard, and even demolish still functional historic housing and build new structures - all without design guidelines or review and at a density, height, and scale that often significantly differs from others in residential and mixed residential-commercial areas at present.

8 Comments

Aram

3/29/2021 09:39:23 pm

Prices in a lot of the city are ~$1000/sq ft. If we don't allow more density, we will go the way of Palo Alto. Density is the best way to reduce our carbon footprint, and to make housing more affordable. I understand that some people would prefer to live in a leafy suburb, but it is unjust to use zoning regulations to force Cambridge to be in that direction.

Cambridge Citizens Coalition

4/2/2021 02:55:13 pm

Hi Aram, thanks for coming to the CCC website and reading our new blog. Alas, Cambridge is already becoming Palo Alto - but worse because we are far smaller and have two big universities here with lots of national and International investors parking their money here in residential real estate. Unlike LA, Minneapolis and many other places, Cambridge is NOT a "leafy suburb" but within the top ten most dense cities in the U.S. And CCC also deeply concerned about the environment; the further loss of our tree canopy (we have already lost over 18% in the last 10 years due to over development) needs to be stopped and reparations made. We cannot do this with the MMH call to decrease requisite open spaces.

4/5/2021 02:21:28 pm

thanks for the reply.
I am deeply confused about the CCC route to affordability. If you keep neighborhoods zoned single-family-only housing, keep parking requirements, setback rules that are violated in 80% of existing lots, etc. then it seems like you will reduce the total amount of housing, and because of how supply and demand works, making housing more expensive. Good for you if you bought already, but if you care about the environment, surely you don't like all those people commuting into work and living in larger houses in the suburbs.

As for trees, I love trees and living around them, but please don't confuse urban trees with helping the environment. A mature growing tree absorbs maybe 50lbs/year of CO2 optimistically. (This is reversed of course if the tree is cut down, and reduced if it's being trimmed or prevented from growing to full size.) According to https://coolclimate.org/calculator a typical household in Cambridge uses 38 tons/year of CO2 and a typical household in, say, Arlington, uses 52 tons/year. So if you stop climate change by displacing a household from Cambridge to the nearest suburb, you had better replace them with 560 trees that will grow forever.

4/6/2021 12:41:21 am

CCC submitted a zoning petition that would have ended zoning for exclusively single family housing (SFH)allowing owners to add units within the shells of the existing structures plus modest additions. Alas the petition never made it out of staff in time for a full assessment. You can read the petition on our website. That said, SFH comprises only about 7% of the housing here. Equally important for us is to radically slow down gentrification which is forcing out more residents by converting rental units into luxury condos. We also need the city to use its own land to create affordable housing - and purchase more land for this. On commuting - post-Covid, many companies are already planning to have staff work from home (where ever), so there will be far fewer commuters. Your point on trees is simply off base. It takes 30 years for a tree to grow and most newly planted trees in urban settings never survive. Trees help cool the city fas it faces severe impacts of heat generated by development. Cambridge is FAR more dense than neighboring towns so this adds to the problem. Finally companies like Google and the biotechs need to be required to come up with an area housing plan - as they have done in other places like San Francisco - so that Cambridge.is not the only target.

4/7/2021 05:14:17 pm

Sounds like a good petition!
I agree with you on having the city use its own land and on surrounding communities accepting more density (if that's what you mean by an area plan).

I think your view of gentrification has causality backwards. High-paying jobs are moving to Cambridge because tech and biotech clusters are more productive when they're located in the same place. There is now high demand for Cambridge housing. We can choose to allow supply to meet demand, or we can choose not to. In the latter case, market prices will rise. Now it's good to create affordable housing for people with low incomes. Because we have done so little to let the market work, this threshold is now $142,800 for a family of 4 to get Cambridge housing assistance. To lower this we need more market-rate housing. Of course the first units built will be "luxury" (although I would contest that a $600k 1-BR 700sq ft condo is indeed luxurious) but that just represents the pent-up demand from years of underbuilding.

Your views on WFH also seem overoptimistic. Surely the year of covid will be peak-WFH and housing prices are currently $836/sq ft in Cambridge (sorry my $1000/sq ft in my first post was a very rough estimate). *Some* people WFH will keep doing so and some will go back to the office but it is hard to imagine that *more* people will WFH after the pandemic is over. And if you are right and demand for Cambridge housing falls, then all those market-rate multifamily buildings you're afraid of won't materialize, since there won't be a market for them.

As for trees, your point about urban trees not reaching their full potential reinforces my point about their ability to absorb CO2 being limited. Of course they improve the quality of life. But urban trees are not helping the climate if they come at the expense of allowing higher density. Keep in mind that when you displace someone from a Cambridge condo into the suburbs they live in a larger house on a larger lot which means cutting down more trees. The atmosphere doesn't care where the trees are, which is why places like Manhattan are by far the most sustainable.

4/7/2021 07:20:03 pm

here are the missing links from my post
https://www.cambridgema.gov/CDD/housing/forapplicants/middleincomerentalprogram
https://www.redfin.com/zipcode/02139/housing-market

Susan Labandibar

4/13/2021 03:45:25 am

Aram, as a long-time tree activist, urban trees are a huge climate justice issue. The forces of unbridled capitalism will surgically target our most vulnerable trees in Cambridge's poorer neighborhoods, just where they are needed most to mitigate urban heat island effect as our climate warms. A mature tree has the power of 10 room-sized air conditioners- making outdoor recreation possible.

The city of Cambridge is not doing a good job balancing development with urban heat island effect. For the city's recommendations, please see: https://www.cambridgema.gov/~/media/Files/CDD/Climate/climatecommittee/Recommendations/CPAC_UrbanHeatIsland_Recommendation_20150731.pdf?la=en

4/20/2021 03:34:42 pm

Susan, I've seen your name on many Swing Left emails and I appreciate all your good work there.

Certainly urban trees are important for improving livability, and keeping trees is challenging in a dense city. There are many things that we need to balance when building housing: affordability (meaning that market-rate housing should be within reach of people earning the median income); open spaces and trees; transit; equity; and more.

Allowing more density makes most of these problems easier to address, while ideally planning would ensure that transit, open spaces, trees, etc. are not lost in the process. For example, if 10 Cambridge families live in 10 single-family houses then there's less room for trees than if they live in a single 4-story apartment building. Certainly the parking requirements that MMH eliminates are not doing anything for trees. So in general there does not have to be a tradeoff between allowing densities and keeping trees.

But if there *were* a tradeoff, then for most of the people affected by climate change (say people in Bangladesh), they will be better off if Americans move from suburbs and rural areas into cities, and that effect will be FAR bigger than any effect from urban trees. In other words, urban trees make us comfortable locally but have effects on global warming that are negligible compared with everything else at stake.

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