Chapter 40B is a state statute, which enables local Zoning Boards of Appeals (ZBA) to approve affordable housing developments under flexible rules (Comprehensive Permit) if at least 20-25% of the units have long-term affordability restrictions. Each community in the Commonwealth must strive to have 10% of their housing stock qualify as "affordable housing". Wellesley is currently at 6.33%. The 40B statute was enacted to facilitate the construction of low- and moderate-income housing; avoid perceived long delays in developers’ proposals to construct affordable housing; and allow waiver of local zoning by-laws that are not “consistent with local needs.”

The preliminary step, prior to submitting a Comprehensive Permit with the ZBA is to gain Site Eligibility from the a subsidizing agency (MassHousing, Massachusetts Housing Partnership). Minimum project eligibility requirements are that the applicant must be a public agency, non-profit organization, or limited dividend organization; project shall be funded by subsidizing agency under low- or moderate-income subsidy program; and the applicant must control the site.

If Site Eligibility is granted, the applicant can apply for a Comprehensive Permit with the ZBA. The 40B Helpful Information below describes the timing and review process for the Comprehensive Permit applications. At present the Town of Wellesley has 5 projects seeking Site Eligibility.