The Subdivision Regulations require that 15% of the entire parcel being developed be set aside as open space. The open space must be representative of the overall parcel in terms of the amount of steep slopes, wetlands, and other limiting factors on development.
When there is not appropriate or desireable open space located within the development, the Town Planning and Zoning Commission can accept an equivalent amount of appropriate off-site open space or even a fee in-lieu of open space equal to ten percent of the fair market value of the land prior to subdivision (or a flat fee of $3,000 per lot).
When the subdivision is five lots or less and the lots are given to or divided among family members at no cost, there is no requirement for open space, provided that the family members do not in-turn give or sell the properties back to the original owner or otherwise sell the lots.