What does a tabby ruin on Wadmalaw Island have in common with the United Order of Tents Building at 73 Cannon St.?

Both have been listed on the Preservation Society of Charleston’s new “Seven to Save” list.

The list highlights what the society considers are the Lowcountry’s most pressing preservation issues.

It also shows the society’s growing interest in calling attention to historical sites well outside Charleston’s Old and Historic District.

In fact, the only site in the historic district that makes the list is the Ansonborough neighborhood, and that’s being listed not because of any imminent threat to a building but because of concern over the livability effects from both a new cruise ship terminal and a large-scale Gaillard Auditorium makeover.

The new list also shows the society’s constantly evolving outlook as to what’s a good building, one worthy of the city.

The greatest example of this may be the vacant old county library at the northwestern corner of Marion Square. Its modern design originally was attacked by the Preservation Society (and others).

Now the group wants to save it — partly because of its historical significance as Charleston’s first public buildings designed for integrated use and partly because it opposes plans for a tall, new hotel at this site. (The society has sued the city over that hotel’s zoning, and the S.C. Supreme Court could rule as early as this week).

But Evan R. Thompson, executive director of the Preservation Society of Charleston, says the building also has an underappreciated architectural quality, including pink marble slabs cut from the same block so they show a pattern of marks and imperfections.

The seven sites are:Charleston’s “sweet shops,” one-story small commercial buildings mostly found along residential streets north of Calhoun Street. One example is the vacant one at 571/2 Carolina St. Thompson says these are not well protected, nor is there agreement of how they should best be renovated and used.

The Lewis Christian Union Cemetery, a largely abandoned burial ground founded in the late 19th century by a black burial society. It lies near Magnolia Cemetery, and the society already held one clean-up day there recently to remove weeds, trees and trash from the gravestones.

Tabby ruins in Charleston County. Thompson says the society would like to see a survey of how much of this early building material — made from oyster shells, lime, sand and water — remains in the Charleston area. Once that’s known, the society could try to get the sites on the National Register of Historic Places.

Charleston’s historic 11th Ward, an early 20th century neighborhood along the eastern edge of Interstate 26.

Charleston’s midcentury modern buildings, such as the old library noted above, the Federal Building on Marion Square that’s being renovated into a hotel, the College of Charleston’s College Lodge dorm on Calhoun Street and the former Chase Furniture building at 414 King St. Thompson says it’s important that preservationists start talking about these buildings in more depth rather than simply saying whether they like them.

The Ansonborough neighborhood, which some feel is under threat from both cruise ship traffic nearby and a plan to expand and reskin the Gaillard Auditorium.

The United Order of Tents building, one of the largest buildings on one of the largest lots in Charleston’s Cannonborough neighborhood.

The 19th century building is owned by a secretive society that dates to the Civil War era, is run by black women and was founded to help those in need.

Its membership has aged, and the building is in disrepair, with its upper floors no longer used. But Thompson says much of the building’s fabric survives, despite an insensitive concrete block addition.

Thompson says the society is trying to do right but is facing prosecution from the city’s Livability Court, which tackles blighted, unmaintained properties. He notes the city owns properties in worse shape than this and should back off.

“The city needs to take itself to Livability Court before it takes the United Order of Tents to Livability Court,” he says.