Madison - State officials said Thursday that damage to the marble inside and out the State Capitol would cost an estimated $7.5 million.

Cari Anne Renlund, chief legal counsel for the state Department of Administration, said in Dane County court that estimates of damage to marble includes $6 million to repair damaged marble inside the Capitol, $1 million for damage outside and $500,000 for costs to supervise the damage.

Much of the damage apparently has come from tape used to put up signs and placards at the Capitol.

It was not immediately clear how the estimates were made, though the state is apparently relying on opinions by historical architects, one of whom works for the U.S. Park Service.

One concern is the residue from tape that the state says is causing damage to stone and other surfaces inside the Capitol.

Michele Curran, an architectural historian for the National Parks Service who coordinates national historic landmarks in Wisconsin, said she didn’t know how the state had arrived at its damage figures.

She said certain kinds of tape can leave lasting residues on surfaces such as marble or wood if they are improperly removed. But she said only a professional cleaning service experienced in such work and familiar with the situation in the state Capitol could estimate any possible costs.

“They need a quote from a company that specializes in cleaning historic surfaces,” Curran said.

Many of the papers and banners posted in the state Capitol were put up using painter’s tape, which is employed to minimize effects on walls.