Accessory Dwelling Units

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 19 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, role 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 does it benefit?

  1. To provide flexibility for families as their needs change over time and, in particular
  2. provide options for older adults to be able to stay in their homes and
  3. for households with disabled persons;
  • To increase the diversity of housing choices in the Town while respecting the residential character and scale of existing neighborhoods;
    • To provide a non-subsidized form of housing that is generally less costly and more affordable than similar units in multifamily buildings;
    • To add housing units to 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/.

Key points about ADU’s in Arlington:

Why is this zoning legislation important?

  1. Arlington is losing the diversity it once had. 
  2. It has become increasingly difficult for residents who have grown up and grown old in the town to remain here. 
  3. 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. 
  4. 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?

  1. Families who need flexibility as their needs change over time
  2. Older adults who need support and/or income to stay in their OWN homes
  3. Households with disabled persons
  4. Residents who value a diversity of housing choices in the Town
  5. People needing a non-subsidized form of housing that is generally less costly and more affordable than similar units in multifamily buildings
  6. People concerned about climate change who want more “sustainable” living options in town

What authority and established policy is this ADU article built on?

  1. Arlington’s Master Plan is the foundational document establishing the validity and mission for pursuing the zoning change that will allow Accessory Dwelling Units.
  2. 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.
  3. The Master Plan states that the American Community Survey (ACS) reports 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?

  1. To be successful, they minimize restrictive requirements for ADU approval.
    1. According to a 2017 study by Alexandra Levering, Tufts University,  (https://equitable-arlington.org/2020/02/16/accessory-dwelling-units-policies/), 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.  In 2016 Lexington realized they needed to amend their current ADU by-law to reduce the restrictions.  That enabled them to gain for more ADUs.

Why is it important to avoid additional requirements, and instead respect the existing administration of building codes and life safety codes by town government professionals?

  1. State and local building codes are administered by Town professional staff in Inspectional Services Dept.
  2. State and Federal Life Safety codes are administered by Town professional staff in Fire Dept.
  3. The wide range of housing styles, types and ages will almost certainly require the home owner to hire a professional contractor to bring their property into code compliance for adding an ADU.
  4. The professional contractor will work closely with Town professionals, on a case by case basis, to make sure each property is in compliance before it can be certified for occupancy.
  5. Compliance with Building and Life Safety codes already will make this a complicated process.  If Arlington wants more housing diversity for the “missing middle”, now is the time to move forward with the approval of Accessory Dwelling Units, by amending the Zoning Code with this proposed Article 19.