SOUTH PORTLAND – The City Council will continue to explore several possible places for a new City Hall, including vacant office space in Knightville.

Councilors decided Monday to further study buying part of the building at 100 Waterman Drive, converting Mahoney Middle School and constructing a new building in the parking lot behind the current City Hall.

Councilors rejected options to renovate City Hall, renovate and add to City Hall, convert the former National Guard armory on Broadway, or build a combined campus for City Hall, public works and buses at what’s now the trash transfer station on Highland Avenue.

Councilors consider City Hall their No. 2 priority for public improvement projects, behind a new public works facility that is projected to cost about $8 million.

City Hall’s problems include structural issues, mold, leaks, cramped spaces, energy inefficiency and expensive maintenance. Originally a church property, the building on Cottage Road dates back to 1880.

The city moved into the building in 1931 and put on an addition in 1979. City departments are also housed in three other buildings.

The council’s discussion Monday didn’t indicate a clear favorite among the options presented by City Manager James Gailey.

Mayor Tom Coward and Councilors Linda Boudreau and James Hughes made favorable, if not emphatic, statements about 100 Waterman Drive, while Councilor Tom Blake said he feels there is “a squeeze for Waterman Drive” that he doesn’t appreciate.

Councilor Maxine Beecher described Mahoney Middle School as one of the city’s best-built buildings, and Councilor Rosemarie DeAngelis spoke of the opportunities offered by the school’s large space.

The building at 100 Waterman Drive has been vacant since its construction was completed in 2008. The city would use three of the four floors – totaling 32,000 square feet – for City Hall.

The building is now a shell. The costs to put in flooring, ceilings, bathrooms, offices and other features are estimated to be $1.2 million.

The purchase price is not known. Blake said Andrew Ingalls, a broker with The Boulos Co., told him during a tour this month that the city could have the building for $4.7 million.

Gailey, however, said final negotiations have not been held. He said the $4.7 million figure and others that have appeared in news reports are incorrect.

“It’s not a true number. Plus, we’re only looking at three floors,” Gailey said after the workshop.

The concept for using Mahoney Middle School calls for renovating 40,000 square feet of the 90,000 square feet at an estimated cost of $4.4 million. School officials are considering consolidating the city’s two middle schools at the current site of Memorial Middle School, but any move in that direction could be years away.

A new building on the current site of City Hall is projected to cost $5.8 million. The concept is a scaled-down version of a proposal in 2000 that was ultimately rejected.

In the version presented by Gailey, the building would be 36,000 square feet. The earlier proposal called for 53,322 square feet and amenities such as arboretums.

Coward noted that councilors have another option: stay put in City Hall for a set period without major construction or renovation of the property.

But he urged councilors to make that an affirmative decision, if it’s their choice, rather than simply defaulting to inaction on the matter.

Staff Writer Ann S. Kim can be contacted at 791-6383 or at: akim@pressherald.com