BATH — Planning Director Jim Upham presented the Planning Board with a list of criteria for “smart growth” development that could allow developers to build projects with higher residential densities than currently allowed.

The board, meeting in a workshop session Tuesday when it received Upham’s list of bonus density restrictions, will take his proposal under consideration and recommend any changes. Upham said he expects the board to discuss the matter again in workshop on June 2. It will ultimately be the City Council that decides whether to put the smart-growth development language into effect.

A public hearing will be held on the language once the Planning Board has established the density bonus criteria.

The language as currently drafted applies only to Bath’s most dense residential zone. It surrounds the downtown, where there is no minimum lot size per dwelling unit. In that zone, the language also applies to an area within a half-mile radius of the center of the city, marked as City Hall.

The zone is intended to encourage developments that are within walking distance of downtown, Upham said: “Everything I’ve read says that a walkable distance is a half a mile. People are willing to walk a half a mile to grocery shop; they walk a half a mile home.”

Residential 1 currently requires 6,000 square feet per dwelling unit. Upham asked board members to consider for a later meeting what degree of density bonus they would favor. A doubling of the density allowance, for example, would result in the density requirement decreasing to 3,000 square feet per unit.

One major criterion in Upham’s language is that a development eligible for a density bonus should incorporate green building technologies. Currently the language states that a development must receive certification from one of three entities: the U.S. Green Building Council’s Leadership in Energy and Environmental Design, the National Association of Home Builders or the Green Building Initiative. A “gold” certification would be required from the first two entities.

LEED certification, for example, requires a development to have properly enclosed insulation, use sustainable materials and implement efficient systems for heating and lighting, as well as water-saving appliances.

Before the language goes to public hearing, Upham said he plans to look further into the three entities to see if any stand out as more suitable for Bath, or whether all three could remain in the land use code as certification options for developers.

Among other criteria to be considered by the board are those that include restricting dwelling units to no larger than 1,400 square feet and to be served by public water and sewer; that parking lots be paved with a permeable, paved surface material, and that parking be located either behind the buildings or inside the block and not be visible from the street.

Architect and developer Catherine Davis approached the Planning Board last month about applying a density bonus for her Old Shipyard condominium project, which has gained city approval and is to be built on Front Street at the foot of Pearl Street. Her project is currently approved for 20 units.

Alex Lear can be reached at 373-9060 ext. 113 or alear@theforecaster.net.