One of Gainesville’s oldest architectural jewels is getting polished.

An extensive, six-month renovation project to the exterior of the U.S. Federal Building and Courthouse in downtown Gainesville began this week with workers erecting scaffolding along the Spring Street entrance side.

The neoclassical Georgia marble building was completed in 1910 with an addition built in 1934 and is on the National Register of Historic Places. It is home to the Gainesville Division of the U.S. District Court for the Northern District of Georgia.

Keeley Evans, building manager for the U.S. Government Services Administration, which manages federal buildings, said the restoration project involves replacing all the mortar between the white marble bricks. Similar work was last done in the 1950s, when an inferior product was used that is now disintegrating, she said. The new project will use materials similar to what was used in the original construction, she said.

The building is also getting a new copper roof and foam padding underneath, she said. The roof will retain the original look of the historic building.

Evans could not say how much the project, funded through the GSA budget, is costing. A project manager did not immediately return a message seeking additional information.

The mortar work is expected to take about four months, with an additional two to three months for the roof work, Evans said.

The work was prompted by leaks in the roof that led to rainwater getting into courtrooms and storage rooms, Evans said.

Garland Reynolds Jr., a local architect and historian of Gainesville buildings, said the renovation project is “great news” for the city.

“It’s perhaps Gainesville’s most beautiful building, and certainly architecturally, most historic,” Reynolds said.

The building was considered unusual for a town the size of Gainesville at the time it was built, Reynolds said. Reynolds believes it was built in Gainesville because Helen Longstreet, then the city’s postmaster and the widow of Lt. Gen. James Longstreet, had some pull with President Theodore Roosevelt.

“Gainesville was very fortunate to get a building like it at that time,” Reynolds said.

The 100-year-old building withstood the 1936 tornado that destroyed much of downtown.

James Hatten, clerk of court for the Northern District of Georgia, said the renovation work will be “quite a project” with drilling between every brick around the 48,100-square-foot building.

Hatten said there will be no limitation to public access to the building during the project, with the entrance continuing to be open on Spring Street.

Evans said the project may have to work around some of the judge’s schedules when court is in session.

“There will be a lot of drilling, but it’s not an excruciating, irritating-type noise,” she said.