Potential Solution

An Innovative Effort to Find Needed Housing

Boston Rolls Out New ADU Program


The existing square footage in Boston’s owner-occupied homes provides tremendous untapped potential for addressing key housing policy issues. Boston is now unlocking that potential with the implementation of the new 18-month Additional Dwelling Unit Pilot Program.

The program is a part of Boston Mayor Martin J. Walsh’s 2030 Housing Plan. Given Boston’s strong neighborhood zoning protections, and an equally strong demand for new housing, innovative approaches like this initiative will be vital to achieving the housing plan’s goal.

The new program has two main goals – increasing the available housing stock, and providing homeowners with rental income to subsidize homeownership costs that may otherwise make staying in the home cost-prohibitive.

The program’s innovation is in its use of existing resources – the unused space within owner-occupied dwellings – to find more housing in a city where space is a highly valued commodity. Further, the program’s objectives are realized in a way that minimizes the impacts of growth on neighborhoods protected by the provisions of neighborhood zoning districts and sub-districts.

ADUs have been in use for more than a decade in other cities, primarily on the West Coast, and even a few municipalities here in Massachusetts. However, Boston’s implementation of an ADU program provides a very high-profile opportunity to test this concept in a major urban city with an extremely high housing demand, limited room for new housing growth and a strong set of zoning regulations.

By way of background, the Boston Zoning Code generally consists of three volumes. Volumes II and III primarily regulate zoning in the various neighborhoods. The zoning provisions particular to each neighborhood countenance the city as a city of neighborhoods, each with its own flavor and fabric. However, perhaps unintentionally, these zoning provisions have also prevented the conversion of a homeowner’s unused residential living space into a separate dwelling unit.

To remove this barrier, the Walsh administration created the ADU pilot program by submitting a text amendment to Boston Zoning Commission. Text Amendment 428 was adopted last November and amended the articles of the Boston Zoning Code (BZC) applicable in the three pilot neighborhoods participating in program – East Boston, Jamaica Plain and Mattapan.

The neighborhood articles were amended in two ways: First, a new, previously undefined term – “additional dwelling unit” – was added to the BZC. In summary, an ADU is now defined as a self-contained, “non-transient” residential living unit within the footprint of an existing owner-occupied dwelling.

The amendment also designated ADUs as an “allowed use” in the respective use regulations and tables that apply in the pilot neighborhoods. Prior to this amendment, a building permit application to add an additional dwelling unit in a one-, two- or three-family dwelling would customarily be denied for its nonconformity with the use and/or dimensional requirements under the applicable zoning. To proceed, an applicant would be forced to obtain a zoning variance or other relief through a zoning appeal. An appeal would generally involve a four- to five-month process with the inherent risk of the appeal being denied.

The amendment eliminates the need for a zoning appeal in many cases. By doing so, the program significantly reduces the ADU permitting time to 30 days or less. There is also a cost savings realized in avoiding the zoning appeal process. The homeowner’s savings is complemented by the program also providing zero equity, interest-free construction loans of up to $30,000 and technical support.

To balance the housing policy goals with the protections afforded by zoning, the program established important criteria to qualify for an ADU. The program requires a proposed ADU to:

  • Be owner-occupied.
  • Be located in one of the three pilot neighborhoods.
  • Add no more than one self-contained unit.
  • Have no more than three units on the property after the ADU is completed.
  • Be created without any bump-out, extension or other construction that would increase the gross floor area of the existing building.

The program also requires compliance with the additional parking requirements under applicable zoning provisions. In addition to meeting the program criteria, a proposed ADU permit application must also comply with the construction requirements of the state building code and the applicable provisions of the state sanitary code.

As the program progresses, we must observe true impacts and benefits over the next 18 months. Boston must be as vigilant as it is innovative to ensure any increased density does not politically “scuttle” this program. For example, occupying the ADU beyond the minimum square footage required per occupant, improper trash storage and disposal and other issues inherent to increasing residential density must be anticipated and addressed for the program to succeed beyond the pilot stage.

The program marks a significant innovation for Boston on how regulatory adaptations for existing housing stock can be used to address a demand for more housing. Through this program, Boston once again is proving itself to be a national leader in public policy.

Kevin J. Joyce is of counsel at the law offices of Gerard Doherty, where his practice focuses on transactions and litigation involving real estate, zoning, permitting, administrative law and development.



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An Innovative Effort to Find Needed Housing

by Banker & Tradesman time to read: 3 min
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