521 CMR Residential Unit Design

The Massachusetts Architectural Access Board (MAAB), 521 CMR, is adopted through 780 CMR, the Massachusetts State Building Code, and serves as the accessibility standard for Massachusetts. Note that Massachusetts deletes ICC A117.1 in its entirety. With 521 CMR as the governing accessibility code, designers are generally presented with challenges that are not always prevalent in other jurisdictions. Therefore, it is common to find misunderstandings for scoping standards, and more specifically, the scoping for design of residential apartments and condominiums and the number of accessible units that are required to be provided in the building.

521 CMR addresses the scoping for residential apartments and condominiums in Chapter 9, Multiple Dwellings. The scoping criteria will require either Group 1 or Group 2A units, or a combination of both.  It should be noted that this discussion does not include references to Transient Lodging Facilities (hotels/motels, inns, dormitories, etc.).

The following are the accessible units in defined in 521 CMR. The dimensional requirements for elements in these units are found in 521 CMR Chapters 42-47.

  • Group 1 units: Applies to dwelling units that have features that can be modified without structural change to meet the specific functional needs of an occupant with a disability. Important to note that accessible routes throughout the unit are required in Group 1 units.
  • Group 2A units: Applies to dwelling units that have features similar to Group 1, but have the additional feature of greater floor space to accommodate the needs of occupants who need such space due to their disability.
  • Group 2B units: Applies to dwelling units that contain features that provide, at the time of initial construction, full accessibility without need for further modification.

The following is the criteria for number of accessible units vs. total number of units provided in each residential occupancy.

  • New Construction
    • Where 20 or more units for rent, hire, or lease are provided, 5% must be Group 2A.
      • Remaining are required to be Group 1
    • Where units are for sale (i.e. condominiums), 100% Group 1 are required (Group 2A are not required).
    • 2% hearing impaired rooms (permitted to overlap with other accessible units).
    • Exception for townhouses, for Group 2A units only:
      • Permits a fully accessible flat of comparable size, amenities, etc. to other townhouses
      • Provide space for future installation of a wheelchair lift
      • Provide space for the future installation of a residential elevator
  • Existing Construction (assumes no addition)
    • 5% Group 2A (if renovation exceeds 30% of the full and fair cash value of the building)
    • Remaining are not required to be accessible (i.e. Group 1 not required).

It should be noted that on January 27, 2014 the Board voted to clarify the definition of a townhouse. The townhouse shall be defined as “a single-family dwelling unit constructed in a group of three or more attached units in which each unit extends from foundation to roof with a yard or public way on not less than two sides.  This is impactful to projects that include multi-story units within larger apartment buildings as these types of units are not considered townhouses per 521 CMR.

If you have any questions or concerns about the scoping details for different residential occupancies, please do not hesitate to contact us.