The town of Aquinnah, known for being progressive in planning, this week moved a step closer to adopting a townwide energy conservation district.

Town selectmen on Wednesday submitted a nomination to the Martha’s Vineyard Commission to designate Aquinnah as an energy district of critical planning concern (DCPC). The nomination was filed by Camille Rose, chairman of the selectmen.

Marking a key win for the town of Aquinnah in its long-running legal battle with James J. Decoulos and Maria Kitris, who want to open up Moshup Trail for development, the Massachusetts Appeals Court ruled yesterday on two separate fronts, finding:

• Mr. Decoulos has not won the right to subdivide two lots he owns off Moshup trail.

• The Aquinnah townwide district of critical planning concern is valid.

The Massachusetts Supreme Judicial Court last week upheld the town of Aquinnah and the Martha’s Vineyard Commission in a key leg of a complicated and long-running property rights case that will ultimately decide whether a large swath of rare coastal heathland along Moshup Trail remains forever wild or is opened up to private development.

A divided Martha’s Vineyard Commission last Thursday clashed over whether the technical language in a recently adopted Aquinnah wind bylaw is in synch with a townwide district of critical planning concern (DCPC) approved over 10 years ago.

In the end the commission voted 7-6 that the new bylaw — drafted by the planning board and approved by voters at a November town meeting — does not conform with the guidelines of the townwide DCPC.