The presentation, dated March 11, 2019, includes slides used to present the information necessary to understand the rationale for zoning changes, the location of the zoning areas under consideration and the charts, tables and maps that help describe the situation. The proposed zoning changes, especially articles 6, 7, 8, 11 and 16, only cover changes affecting about 7% of the Town, those parts of the Town that are currently zoned R4-R7 and the B zoning districts.
Related articles
Accessory Dwelling Units (aka “granny flats”)
The following information was presented to the Arlington Redevelopment Board in October, 2020 by Barbara Thornton, TMM, Precinct 16
This Article proposes to allow Accessory Dwelling Units, “as of right”, in each of the 8 residential zoning districts in Arlington.
Why is this zoning legislation important?
Arlington is increasingly losing the diversity it once had. It has become increasingly difficult for residents who have grown up and grown old in the town to remain here. This will only become more difficult as the effects of tax increases to support the new schools, including the high school, roll into the tax bills for lower income residents and senior citizens on a fixed income. For young adults raised in Arlington, the price of a home to buy or to rent is increasingly out of reach.
Who benefits from ADUs?
- Families benefit from greater flexibility as their needs change over time and, in particular providing options for older adults to be able to stay in their homes and for households with disabled persons or young adults who want additional privacy but still be within a family setting.
- Residents seeking an increase in the diversity of housing choices in the Town while respecting the residential character and scale of existing neighborhoods; ADUs provide a non-subsidized form of housing that is generally less costly and more affordable than similar units in multifamily buildings;
- Residents wanting more housing units in Arlington’s total housing stock with minimal adverse effects on Arlington’s neighborhoods.
What authority and established policy is this built on?
Arlington’s Master Plan is the foundational document establishing the validity and mission for pursuing the zoning change that will allow Accessory Dwelling Units.
Under Introduction in Part 5, Housing and Residential Development, the Master Plan states: Arlington’s Master Plan provides a framework for addressing key issues such as affordability, transit-oriented residential development, and aging in place.
The Master Plan states that the American Community Survey (ACS) reports that Arlington’s housing units are slightly larger than those in other inner-suburbs and small cities. In Arlington, the median number of rooms per unit is 5.7. There is a great deal of difference in density and housing size among the different Arlington neighborhoods. The generally larger size of homes makes it easier to contemplate a successful move to encourage ADUs.
What do other municipalities do?
According to a study (https://equitable-arlington.org/2020/02/16/accessory-dwelling-units-policies/), by 2017 65 out of 101 municipalities in the greater Boston (MAPC) region allowed Accessory Dwelling Units by right or by special permit. The average number of ADU’s added per year was only about 3. But by 2017, Lexington had 75 ADUs and Newton had 73. Both of these communities were among about 10 “as of right” municipalities in the MAPC region. This finding suggests that communities with more restrictions are less likely to see any significant affordable housing benefits.
Even in the midst of a housing crisis in this region, according to Amy Dain, housing expert, (https://equitable-arlington.org/2020/02/18/zoning-for-accessory-dwelling-units/) most municipalities still have zoning laws that restrict single family home owners from creating more affordable housing.
And this is despite the fact that, as according to Banker & Tradesman, March 10, 2020: https://www.bankerandtradesman.com/63-percent-in-greater-boston-back-adus/, 63% of people in the region approve of ADUs. California has recently passed strong pro-ADU legislation. A study by Zillow further corroborated this strong interest in communities across the US, including our region. https://equitable-arlington.org/2020/03/10/adu-popularity/.
Learn more about Accessory Dwelling Units/ “Granny Flats” here: https://planning.org/knowledgebase/accessorydwellings/

Article 16 is a proposal to encourage the production of affordable housing in the town of Arlington. I brought this article to town meeting for several reasons, namely, our increasing cost of housing and our increasing cost of land. Arlington is part of the Metropolitan Boston area; we share borders with Cambridge, Somerville, and Medford, and are a mere 5.5 miles from Boston itself. Years ago, people moved out of cities and into the suburbs. That trend has reversed during the last decade, and people are moving back to urban areas, including Metro-Boston. Metro-Boston is a good source of jobs; people come here to work and want to live nearby. That obviously puts pressure on housing prices, and Arlington is not immune from that pressure.
Another reason for proposing Article 16 was my desire to start a conversation about the role our zoning laws play in the cost of housing, and how they might be used to relieve some of that burden. During the 20th century people discovered that one cannot draw a line on a map and say “upper-class households on this side, lower-class households on that side”, but one can draw a line on a map and say “single-family homes on this side, and apartments on that side”. For all practical purposes, the latter achieves the same result as the former. When zoning places a threshold on the cost of housing, it determines who can and cannot afford to live in a given area.
Today 70% of Arlington’s land is exclusively zoned for single family homes, the predominant form of housing in town. In 2013, the median cost of a single-family home was $472,850; this rose to $618,800 in 2018 — an increase of 31%. We can break this down further. The median building cost for a single-family building rose from $226,300 in 2013 to $248,100 in 2018 (an increase of 9.6%), and the median cost for a single-family lot rose from $243,700 to $360,900 (an increase of 48%). Land is a large component of our housing costs, and it continues to rise. Certain neighborhoods (e.g., Kelwyn Manor) saw substantial increases in land assessments in 2019, enough that the Assessor’s office issued a statement to explain the property tax increases. To that end, multifamily housing is a straightforward way to reduce the land costs associated with housing. Putting two units on a lot instead of one decreases the land cost by 50% for each unit.
Article 16 tries to encourage the production of affordable housing (restricted to 60% of the area median income for rentable units and 70% for owner-occupied units). It works as follows:
- Projects of six or more units must make 15% of those units affordable. This is part of our existing bylaws.
- Projects of twenty or more units must make 20% of those units affordable. This is a new provision in Article 16.
- Projects of six or more units that produce more than the required number of affordable units will be eligible for density bonuses, according to the proposed section 8.2.4(C). Essentially, this allows a developer to build a larger building, in exchange for creating more affordable housing.
- Projects of six or more units that produce only the required number of affordable units are not eligible for the density bonuses contained in 8.2.4(C).
- Projects of 4-5 units will be eligible for the density bonuses in section 8.2.4(C), as long as they are of a use, and in a zone contained in those tables. This provision is intended to permit smaller apartments and townhouses, filling a need for residents who don’t necessarily want (or may not be able to afford) a single-family home. This provision can help reduce land costs by allowing a four-unit townhouse in place of a duplex, for example.
Historically, Arlington has had mixed results with affordable housing production, mainly due to the limited opportunity to build projects of six units or more. It is my hope that the density bonuses allow more of these projects to be built.
In conclusion, the problem of housing affordability in Arlington comes from a variety of pressures, is several years in the making, and will likely take years to address. I see Article 16 as the first step down a long road, and I ask for your support during the 2019 Town Meeting. I’d also ask for your support on articles 6, 7, and 8 which contain minor changes to make Article 16 work properly.
Massachusetts’ 2020 Economic Development Bill included a set of housing choice provisions: these require communities served by the MBTA to provide a district of reasonable size where multi-family housing is allowed by right. The law gives us significant flexibility to design a district that best suits our needs, but the district must allow housing suitable for families with children, without age restrictions, and at a rate of at least 15 dwelling units per acre. Arlington is one of 175 MBTA communities in Massachusetts that share in the responsibility for meeting these requirements.

The law requires a “district of reasonable size”, but what does that mean? Throughout much of 2021 the Massachusetts Department of Housing and Community Development (DHCD) worked on a set of supporting regulations that set the district requirements according to the type of transit service a community has, the number of existing homes in the community (as of the 2020 Census), and the amount of developable land near transit stations. The specifics vary by community, but here is what the requirements mean for Arlington:
- Our district needs a capacity of (at least) 2,046 homes. This isn’t a requirement to build 2,046 additional homes; instead, it reflects the total number of homes that district might contain in the future. For example, if a parcel with a two-family home were rezoned to allow a three-family home, that single parcel would have a capacity of three.
- Our district needs to allow multi-family housing by right. “By right” means that the development only requires a building permit, where the Building Inspector determines whether the project complies with zoning and building codes. While Arlington allows multi-family housing (three or more dwellings on a single parcel) in some areas, such projects are not allowed by right.
- Our district needs to allow (at least) 15 dwellings/acre. This is more or less in line with the density of the streetcar suburbs that were built in East Arlington during the 1920s. Although portions of Arlington likely meet the density requirement, none of these areas currently comply, as they don’t allow multi-family housing to be built by right.
- Our district needs to be at least 32 acres, but it could be larger. We have flexibility here, as we’ll discuss in a moment.
- Finally, due to the lack of developable land around the Alewife T station, Arlington is free to locate its multi-family district (or districts) anywhere in town. We’re not tied to any particular geographic location.
The new law’s requirements provide Arlington with a great deal of flexibility. We’re free to place our district (or districts) anywhere in town, and we’ll be able to choose from a variety of options as long as they meet the requirements set forth above. For example, providing the capacity of 2,046 homes in the minimum district size of 32 acres would give us a density of 64 dwellings/acre; roughly the scale of mid-rise apartment buildings. On the other hand, if we went with the minimum density of 15 dwellings/acre, we’d have a 135 acre district that allowed smaller multi-family homes. Our district can be anywhere within this range; we also have the option of having multiple districts, with smaller multi-family buildings in some areas of town and larger multi-family buildings in others.
Arlington has a track record of producing thorough and comprehensive planning documents, such as our Master Plan, Net Zero Action Plan, Sustainable Transportation Plan, and Housing Production Plan. These plans contain plenty of building blocks that could be used to formulate a compliant multi-family district. Viewed in that light, the MBTA community requirements are an opportunity to meet some of the goals we’ve already set for ourselves; we just have to go about it in a way that satisfies the law’s new requirements.
Arlington has one unique consideration, which doesn’t apply to most MBTA communities. In 2020, Arlington’s Town Meeting sent a home rule petition to the state legislature, asking for permission to regulate the use of fossil fuels in new building construction; it’s an important component of our plan to become carbon-neutral by 2050. A number of other communities in the Commonwealth filed similar petitions, and the legislature responded by establishing a pilot program: ten cities and towns will be allowed to enact “fossil fuel bans”, but only if they (a) have 10% subsidized housing, (b) achieve safe harbor via compliances with an approved housing production plan, or (c) establish a multi-family district of reasonable size by February 2024. Arlington doesn’t meet the subsidized housing requirement (only 6.54% of our homes are on the subsidized housing inventory), and we’re unlikely to gain safe harbor status during the next year; our most viable path to participation hinges on meeting the multi-family requirements.
In summary, the multi-family requirement for MBTA communities creates new requirements for Arlington, while also presenting us with new opportunities: the opportunity to meet planning goals, the opportunity to meet sustainability goals (e.g., by regulating fossil fuel use in new construction), and the opportunity to reimagine how we do multi-family housing in Arlington as our town moves forward into the twenty-first century.
A portion of Envision Arlington’s town day booth was designed to spark a community conversation about housing. Envision set up a display with six poster boards, each representing a housing-related topic. Participants were given three dots and asked to place them on the topics they felt were most important. There were also pens and post-it notes on hand to capture additional comments. This post is a summary of the results. You could think of it as a straw-poll or temperature check on the opinions of town day attendees.
Social Justice Issues
Aiming for a diverse population by income and race; and being vigilant about identifying and neutralizing barriers to this goal.

197 dots, plus a post-it note that reads “Increasing housing while preserving open space” (with three dots).
Lifestyle Options
Providing for different lifestyles: empty nesters, single millenials, young parents, families, walkable neighborhoods.

149 dots and four post-it notes:
- No more new 5-story buildings with no setbacks. Ugly. (3 dots)
- Why must we maintain our high carbon footprint with single family homes and cars?
- I want to live in a wofati (eco building) (Woodland Oehler Freak-Cheap Annualized Thermal Intertia). Not so legal, one day the norm. Thank you Arlington.
- Connect to transit. Less single family housing with dedicated parking.
Housing Affordability
Affordable housing from subsidies, from construction of smaller units, or from building more housing to reduce the bidding price on current Arlington homes.

308 dots, with 10 post-it notes
- We don’t need more housing. People need to be able to afford to stay in their homes.
- Get Arlington out from the clutches of real estate lobby. (1 dot)
- Wrong categories. Includes affordable housing and development which displaces low and moderate income housing
- Restrictions on teardowns of small homes
- Keep older apartment buildings. They are cheap and affordable.
- Rent control and oversight. “I can only afford to stay because I live in a place that is not secure and in disrepair.”
- Rent control. Please reinstate so that rent is affordable.
- “Affordable” subsidized housing invades your privacy. Every year need all bank stubs, 401(k), like a criminal.
- Build more housing. Build more duplexes, triplexes, etc. Upzone neighborhoods. More transit corridors. Renew calls for a red line stop. Build up the downtown to encourage more density and housing in the same buildings as businesses. More housing + transit = a better society.
- Protect neighborhoods
This was clearly the topic that drew the most response. Arlington housing is expensive.
Maximizing Flexibility of Home Space
Providing for aging parents or childcare providers with a place in your home or getting help paying the mortgage by having a rentable space.

81 dots, and three post-it notes:
- Change zoning to allow accessory dwelling apartments (aka ADUs, granny flats, in-law apartments) (1 dot)
- Want nearby widowed mom to live in own house.
- Accessible rentals, not up 3 flights of stairs.
Doing more with Existing Resources
Examining current Arlington Housing Authority, Housing Corporation of Arlington, and aging apartment buildings for addressing new housing needs.

143 dots, and five post-it notes:
- Fix transportation infrastructure. Peope can live farther out and still get to work. (4 dots)
- Extend red line to Arlington center and heights. (7 dots)
- None of the above. Keep taxes low. (1 dot)
- Accessible for aging residents. Age in place.
- Do something about empty store fronts.
Setting a ten-year goal for new housing
Determining what Arlington’s housing goals should be, and setting about following through on the necessary zoning and incentives to get what we want.

119 dots, and three sticky notes:
- Why is America low-density? Why is this country slave to the auto? More housing near transit!
- Who is “we”?
- There is too much housing density now. Need business area to attract business.
Observations
As noted earlier, the cost of housing seemed to be the main issue of concern. This is understandable: housing prices in Arlington (and the region in general) have been on an escalator ride up since about 2000 or so. That’s led to our current high cost of housing, and also to a form of gradual gentrification. When housing is more expensive than it was last year, a new resident in town has to make more money (or be willing to spend more on housing) than last year’s new resident.
I see at least two broad responses to this: one is to keep the status quo, perhaps returning to the inexpensive housing of decades past. The other is for more multi-family housing, and more transit-oriented development. It will be interesting to see how these dynamics play out in the future.
There’s also recognition of the importance of older “naturally affordable” apartment buildings. Arlington was very pro-growth in the 1950s and 1960s; that’s fortunate, because it allowed these apartments to be built in the first place. On the downside, we haven’t done a good job of allowing new construction into the pipeline during recent decades. Buildings depreciate, so a new building is worth more than one that’s ten years old, which is worth more than one that’s twenty years old, and so on. At some point, the old apartments are likely to be refurbished/upgraded, and they’ll become more expensive as a result.
This is only the beginning of the conversation, but at least we’re getting it going.

The kick-off event for updating Arlington’s Comprehensive Plan (formerly called the Master Plan) is just around the corner on April 3rd from 7-8:30 PM in the Arlington High School Cafeteria!
A Comprehensive Plan is a long-range plan for the Town, and an opportunity for the community to come together and imagine what Arlington could look like in ten or fifteen years. It covers things like housing, business development, parks and open spaces, town services and facilities, and transportation. The kickoff meeting is the first step in building that vision.
Arlington residents of all ages are invited to attend this event, where you can expect a presentation followed by small group discussions. The effort will continue throughout the year, and it’s important to hear from as many residents as possible. Please join if you can!
For more information and to add the meeting to your calendar, see ArlingtonMA.gov/CompPlan.
A report by Mass Housing Partnership’s Shelly Goehring looks at Arlington’s housing development history and policies to understand how municipal action and inaction can contribute to housing inaffordability and can limit the population diversity within a community. The report implies that it has been difficult historically for reputable housing developers to work with the regulatory structure within Arlington to get housing built.
Massachusetts has the nation’s 2nd largest gap in homeownership between households of color (31% own homes) and white households (69% own homes).
See the complete report for more information.



(This post originally appeared as a one-page handout, distributed at The State of Zoning for Multi-Family Housing in Greater Boston.)

This chart shows the assessed value of Arlington’s low density housing from 2015–2019 (assessed values generally reflect market values from two years prior). During this time, home values increased between 39% (single-family homes) and 48% (two-family homes). Most of the change comes from the increasing cost of land. As a point of comparison, the US experienced 7.7% inflation during the same period. (1)
Arlington has constructed six apartment buildings in the 44 years since the town’s zoning bylaw was rewritten in 1975; we constructed 75 of them in the preceding 44 years.(2) Like numerous communities in the Metro-Boston area, we’re experiencing a high demand for housing, but our zoning regulations have created a paper wall that prevents more housing — including affordable housing — from being built.
Communities need adequate housing, but they also need housing diversity: different types of housing at different price points. The housing needs of young adults are different than the housing needs of parents with children, which are in turn different than the housing needs of senior citizens. As demographics change, housing needs change too. Keeping people in town means providing them with the opportunity to upsize or downsize when the need arises.
If Arlington’s housing costs had only increased with the rate of inflation, the cost of single family housing would average $581K, over $170K less than today. The median household income in Arlington is about $103K/year.(3) Buying an average single family-home with that income on a typical 30-year mortgage would require approximately 46% of a household’s monthly income.(4)
Either homes in Arlington will only be available to people who have much more substantial incomes than current residents, or the town will find a way to balance the rapidly growing cost of land against the housing needs of its current citizens, those still in school, those preparing to downsize as well as those looking for a bigger space.
In addition, Arlington’s commercial economy will thrive with a greater number of housing units so we can keep the empty nesters, and the new college graduates who have lived in the town for years, as well as welcome new Arlingtonians to support our local businesses, restaurants and other services.
Our Town, like others in the state, is looking for ways to balance the needs of our citizens with the market forces of rising land costs while maintaining a healthy, diverse community.
Footnotes
- The inflation amount comes from Inflation amount from https://data.bls.gov/cgi-bin/cpicalc.pl.
- Figures on multi-family unit construction are taken from Arlington Assessor’s data. They reflect multi-family buildings that are still used as rental apartments.
- Income levels come from 2013-2017 ACS 5-year data for Arlington, MA.
- Assuming 10% downpayment, 4% interest, $800/year for insurance, and Arlington’s $11.26 tax rate, the monthly mortgage payment would be nearly $4000/month.
I’ve had an annual ritual for the past several years: obtain a spreadsheet of property assessments from the Town Assessor, load them in to a database, and run a series of R computations against the data. I started doing this for a number of reasons: to understand what was built where (our zoning laws have changed over time, and there are numerous non-conforming uses), the relationship between land and building values, the capital costs of different types of housing, and how these factors have changed over time.
I’d typically compile these analyses into a fact-book of sorts, and email it around to people that I thought might be interested. This year, I’m going to post the analyses here as a series of articles. This first installment contains basic information about Arlington’s low-density housing: single-, two-, and three-family homes, as well as condominiums. Condominiums are something of an oddball in this category — a condominium can be half of a two-family structure, part of a larger residential building, or somewhere in between. There’s a lot of variety.
Here’s a table showing how the number of units has changed over time, since 2013.
| land use | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 |
|---|---|---|---|---|---|---|---|---|
| Single Family | 7984 | 7983 | 7991 | 8000 | 7994 | 7994 | 7998 | 7999 |
| Condominium | 3242 | 3304 | 3367 | 3492 | 3552 | 3662 | 3726 | 3827 |
| Two-family | 2352 | 2332 | 2308 | 2282 | 2263 | 2218 | 2183 | 2139 |
| Three-family | 207 | 201 | 196 | 194 | 193 | 190 | 185 | 182 |
Arlington’s predominant form of housing — the single family home — has stayed relatively static; we’ve added 15 over the last seven years. The number of condominiums has increased significantly: +585 over seven years. That, coupled with the reduction of two-family homes (-213) and three-family homes (-25) leads me to believe that a fair number of rental units have been removed from the market.
Next, I’d like to look at how these homes are spread across our various zoning districts. (The “Notes” section at the bottom of the post explains what the zoning district codes mean).
| Zone | Single-Family | Condo | Two-family | Three-family |
|---|---|---|---|---|
| B1 | 8 | 22 | 13 | 11 |
| B2 | 1 | 4 | 1 | |
| B2A | 1 | 18 | ||
| B3 | 59 | 4 | ||
| B4 | 1 | 59 | 5 | 5 |
| B5 | 1 | 1 | ||
| I | 8 | 18 | 7 | 1 |
| R0 | 502 | |||
| R1 | 6798 | 168 | 200 | 7 |
| R2 | 647 | 1816 | 1881 | 124 |
| R3 | 4 | 39 | 11 | 17 |
| R4 | 23 | 79 | 2 | 3 |
| R5 | 3 | 616 | 5 | 4 |
| R6 | 2 | 686 | 8 | 7 |
| R7 | 1 | 243 | 2 | 1 |
A few points to note:
- R0 is our newest district, which was established in 1991. It consists only of conforming single-family homes.
- R1 is Arlington’s original (per 1975 zoning) single-family district. It’s predominantly single-family homes, but there are a fair number of two-family homes, and even a few three-families. The presence of condominiums suggests additional multi-family homes (that consist of two or more condominiums)
- R2 is predominantly two-, and three-family homes. Although three-family homes are no longer allowed in this district, R2 has the largest number of three-families in town.
- Residential uses are no longer allowed in the industrial (I) districts, but the I districts contain 34 homes. These buildings pre-date the current zoning laws (aka “pre-existing non-conforming”). A good portion of the Dudley street industrial district is a residential neighborhood.
I’m pointing out these conformities (and non-conformities) for a reason. The zoning map (and use tables) dictate what is allowed today, along with specifying a vision for the future. Our zoning bylaw happens to contain a strong statement to this effect: “It is the purpose of this Bylaw to discourage the perpetuity of nonconforming uses and structures whenever possible” (section 8.1.1(A)). Despite the strong statement of intent, it can take decades (if not generations) for a built environment to catch up with the bylaw’s prescriptions.
I’ll finish this post with a breakdown of how condominiums are distributed across the various zoning districts:
| Zone | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | delta |
|---|---|---|---|---|---|---|---|---|---|
| (N/A) | 14 | 15 | 0 | 0 | 0 | 0 | 0 | 0 | -14 |
| B1 | 16 | 16 | 18 | 18 | 18 | 22 | 22 | 22 | 6 |
| B2 | 2 | 2 | 2 | 2 | 4 | 4 | 4 | 4 | 2 |
| B2A | 19 | 18 | 18 | 18 | 18 | 18 | 18 | 18 | -1 |
| B3 | 55 | 55 | 61 | 59 | 59 | 59 | 59 | 59 | 4 |
| B4 | 47 | 47 | 59 | 59 | 59 | 59 | 59 | 59 | 12 |
| I | 18 | 18 | 18 | 18 | 18 | 18 | 18 | 18 | 0 |
| R1 | 140 | 144 | 146 | 148 | 150 | 154 | 162 | 168 | 28 |
| R2 | 1355 | 1406 | 1456 | 1518 | 1574 | 1670 | 1723 | 1816 | 461 |
| R3 | 22 | 25 | 28 | 31 | 31 | 37 | 37 | 39 | 17 |
| R4 | 65 | 67 | 67 | 79 | 79 | 79 | 79 | 79 | 14 |
| R5 | 616 | 616 | 616 | 616 | 616 | 616 | 616 | 616 | 0 |
| R6 | 630 | 632 | 635 | 683 | 683 | 683 | 686 | 686 | 56 |
| R7 | 243 | 243 | 243 | 243 | 243 | 243 | 243 | 243 | 0 |
The last column (“delta”) shows the difference between 2013 and 2020. The largest increase occurred in the R2 (two-family) district, followed by R6 (medium-density apartments, where most of the increase took place in 2014) and R1 (single-family).
That it will do it for the first installation. In the next post, we’ll look at how the cost (assessed values, actually) of Arlington’s low density housing has changed over the last seven years.
Here is a spreadsheet, containing the various tables shown in this article.
Notes
Arlington’s zoning map divides the town into a set of districts, and each district has regulations about what kinds of buildings and uses are allowed (or not allowed). The districts mentioned in this article are:
- B1 (Neighborhood Office district)
- B2 (Neighborhood Business distrct)
- B2A (Major Business District)
- B3 (Village Business District)
- B4 (Vehicular-Oriented Business District)
- I (Industrial District)
- R0 (Single-Family, large-lot district)
- R1 (Single-Family Distict)
- R2 (Two-Family District)
- R3 (Three-Family District)
- R4 (Townhouse District)
- R5 (Low-Density Apartment District)
- R6 (Medium-Density Apartment District)
- R7 (High-Density Apartment District)
Arlington’s Zoning Bylaw describes each district in detail (see sections 5.4.2, 5.5.2, and 5.6.2)