Portland’s Historic Preservation Board is considering whether to designate House Island as a historic preservation district, a move that could affect development plans for the island prominently located near the entrance of Portland Harbor.

Two board members submitted the letter nominating House Island as a historic preservation district last month after Michael Scarks purchased the 24-acre island best known for Fort Scammel, a military fort that dates to the early 1800s.

Scarks has indicated that he wants to build a limited number of luxury homes on the island but has not yet decided what to do with three buildings that were once part of a federal immigration quarantine station that operated on House Island in the early 1900s. Scarks said he would allow limited public access to the fort.

Designation as a historic preservation district could prevent Scarks from demolishing the three buildings, all of which date to 1907.

Scarks said Wednesday night that he was still waiting to learn more about what, exactly, a designation would mean for the island.

Greater Portland Landmarks supports the nomination. In a letter filed with the city, the organization’s executive director, Hilary Bassett, wrote that House Island is “an important cultural landscape and its buildings, including Fort Scammel and the immigration-era structures, tell the story of Portland’s military and social history.”

House Island is located near Portland Harbor’s entrance, between Fort Gorges and Cushing Island. In addition to harboring a military fort and Maine’s version of Ellis Island, House Island has been used over the centuries as a large fish processing center, a destination for corporate retreats, a lobster pound and a tourist attraction.

The Historic Preservation Board held an initial workshop on the nomination Wednesday night. The board is scheduled to hold a public hearing on Sept. 3 before making a recommendation on the nomination to the city Planning Board.