PORTLAND — The effort to turn House Island into a city historic preservation district is headed to the City Council after receiving a unanimous Planning Board recommendation on Nov. 25.

If City Councilors approve, the privately owned Casco Bay island of about 24 acres would become a district where development would be subject to oversight by the Planning and Historic Preservation boards.

A City Council order creating the historic preservation district will require two readings and a public hearing before a vote.

House Island is now owned by developers Michael Scarks and Vincent and Christina Mona. The island’s southern end features Fort Scammell, which dates to the War of 1812. The northern end was used as a processing and quarantine center by federal immigration authorities until the mid-1920s.

Scarks bought the island from Harold Cushing for $2.5 million in late May, according to city tax records. During a hearing with the city Historic Preservation Board on Oct. 1, he announced he sold the northern half to the Monas, who are principals of Naples, Florida-based Three Palms Design.

The island was nominated for placement in the district by HPC board members Penny Pollard and Bruce Wood on July 16. The Board approved the nomination Oct. 1.

Scarks and the Monas did not attend the Nov. 25 Planning Board meeting or offer comment regarding the recommendation.

At the Oct. 1 HPC meeting, the Monas and Scarks said the historic preservation district designation was unnecessary and a possible impediment to development plans they said would reflect the island’s history.

The Monas described renovating the last farmhouse near Capitol Hill in Washington, D.C., and said they would bring the same spirit to work on House Island.

In an Oct. 3 email, Vincent Mona elaborated on his intentions.

“After we bring back the three existing houses to their former glory, we may look at old photos and rebuild a few for my very large family,” he said.

Scarks is not opposed to placing Fort Scammell in a historic preservation district and said he wants to build a couple of homes on the southern end, away from Fort Scammell.

“We hope (the process) is collaborative and without restrictions,” he said Oct. 1.

The designation is supported by Greater Portland Landmarks, which has sought protection for the island for a couple of years.

Executive Director Hilary Bassett said Tuesday the designation offers needed long-term protection.

“I think the HPC review showed it meets all the criteria according to the city ordinance,” Bassett said. “It is a long time decision irrespective of current ownership. We don’t know who tomorrow’s owner is, this is helping ensure it is kept intact for future generations.”

Bassett said the additional oversight can also be more collaborative than imagined while protecting public interest.

“This is nationally significant, it is not just any old place,” she said.

The island was sold to Harold Cushing almost 60 years ago by the federal government. At the Oct. 1 HPC meeting, he said he opposed additional zoning on the island.

“I am the bad guy who would not put any restrictions on that island. If you don’t own it, don’t restrict it,” he said, adding his efforts to sell the island to the federal, state or city governments were all unsuccessful.

David Harry can be reached at 781-3661 ext. 110 or dharry@theforecaster.net. Follow him on Twitter: @DavidHarry8.