Acton’s zoning bylaw divides the town up into multiple areas where different uses of the land are allowed, limited, or prohibited. In one sense, zoning is a map of a desired future: what would be the best ways to arrange what happens in town? When zoning changes, uses do not immediately change. First, there is a grace period where changes that are in the process of being permitted can proceed even if they do not conform to the new zoning; next, uses that are already happening are ‘grandfathered’ in as legal uses as long as the parcel does not change in way that would trigger the new requirements. Thus, the process of changing zoning can cause unintended consequences, as landowners sometimes rush to get soon-to-be-illegal uses in place before the zoning passes.
Zoning changes require a two-thirds vote at Town Meeting, and a substantial percentage of large proposed zoning changes do not pass.
Environmental concerns about the impacts of extra building and the risks of certain land uses are part of what drive zoning, but they are hardly the only concerns. Earlier zoning also was used to exclude people of lower incomes from living in Acton, and other zoning was meant to maximize certain kinds of economic development. Both of these kinds of zoning create environmental problems of sprawling development.