NASHVILLE, Tenn. -- A taxpayer group funded by a neighbor of the governor's mansion is criticizing the spending for construction and renovation to the executive residence in upscale Oak Hill.

Tennesseans for Accountability in Government, created by a donation from a Nashville auto dealer, called on the state Tuesday to provide cost details on renovations and the addition of an underground banquet hall at the mansion.

Susan Kaestner, vice president of the group, said the facility was an irresponsible waste of taxpayer money and the governor could use existing venues in Nashville for meetings. She said the group was created by a donation from Lee Beaman, a neighbor, but that this wasn't a neighborhood group focused solely on the local impact to the community.

"The renovations has gone way past reasonable," Kaestner said, adding the state hasn't been forthcoming with plans and costs.

When Gov. Phil Bredesen took office in 2003, he agreed not to move in the home so it could be renovated. First Lady Andrea Conte has said the new underground facility is needed so the mansion -- which was a private residence before it became an official home for Tennessee's governors in 1949 -- will have sufficient and suitable space for meetings and entertainment.

The private donations she has raised, which totals about $8 million now, is being allocated almost solely for the new Conservation Hall, said state architect Mike Fitts. No state funds will go into that facility, which is scheduled to start construction in January, he said.

But a spreadsheet of the costs of the renovations showed that $12.8 million in state funds has been allocated for the overall upgrade and maintenance of the property, which includes installing new roof, widening the driveway, adding elevators and improving security. Some of those improvements, such as the elevators and the larger driveway, were necessary in the plans for the underground facility, he said.

"What the state is really paying for is the maintenance. The state is partly paying for the improvements," Fitts said. "We think it fits as a reasonable cost for the state."

The Tennessee Center for Policy Research, a conservative watchdog group that also criticized former Vice President Al Gore for electricity usage at his Nashville home, issued a release saying Conte was dishonest when she said a majority of the cost would be raised privately.

Beaman and other residents in the neighborhood met with Conte in November, who said the refurbished governor's mansion will be unobtrusive, quiet and environmentally friendly. Without the underground space, the governor would have to continue to entertain in temporary tents on the property, which don't protect well against noise or weather.

But Beaman said the first lady didn't assuage his concerns about the project at the meeting.

"I think this is an important issue that the people of Tennessee need to be informed about and express an opinion about," Beaman said.

"I think taxpayers have to stop this project, if it is to be stopped," Kaestner said, adding the state building commission should take a closer look at the plans.

Fitts said the underground facility doesn't impede on the neighborhood and doesn't overpower the architecture of the home built in 1931.

"We can take the money and build a brand new facility, but it wouldn't have the rich history for Tennessee," Fitts said.

Nina Thomas, who said she lives in the area, said the state could be spending the money elsewhere.

"I'd much rather see those funds used for education," Thomas said.