A proposed new library could cost the citizens of Natrona County $43.25 million, if a ballot measure passes in November.

The Natrona County Library Board of Trustees approved the ballot language in its meeting Thursday night for a 96,000-square-foot building that could cost $48.25 million.

Library Director Bill Nelson said plans call for about $5 million from the sale of the current building and money from the library foundation, leaving $43.25 million to come from an optional 1 percent sales tax.

If approved, the sixth-cent sales tax would run for about 27 months before expiring.

The board had several options for the size and estimated cost of the building.

The first option was for a 96,000-square-foot building with an expectation that construction costs would increase 12 percent each year. Under those assumptions, the cost would be $44.9 million.

Nelson said construction costs currently are rising about 1 percent each month, but that is high and may not be a sustained increase.

A second option was for the same-sized building but at a cost increase of 8 percent each year. This would be $42.3 million.

The original plan looked at an increase of 4 percent each year, but Nelson said after future examination of rising construction costs, including fuel prices, 8 to 12 percent was more realistic and conservative.

The third and fourth options called for a smaller library with 90,000 square feet. Even though the reduction would not limit the ability to operate as a library, Nelson said the extra 6,000 square feet may be needed in the future.

Using 90,000 square feet at a rate of 12 percent, the cost would be $43.1 million, and at a rate of 8 percent it would be $40.5 million.

Library board President Chris Mullen said this would be the library for the next 50 years or more, and he doesn't want to ask the voters to spend this much money without giving them the library they deserve.

Shrinking the library too much to lower costs is "essentially just changing the address," he said.

Nelson said a new building is needed to account for a current deficiency in areas such as study rooms, group meeting space and parking.

The cost is more than originally expected. Some of the earlier estimates before analysis were around $30 million, but, Nelson said, cost of construction has increased immensely in the past several years.

"There are no gold-plated faucets," Mullen said about the new building. "Or extravagancies."

The project manager and designer, Michael Mackey, said he kept the plans largely to only the elements the library needs.

The board ultimately decided on $43.25 million, which is between the 8 and 12 percent estimates. This lowers the cost slightly but still allows for construction cost increases, said board member Randy Buffington.

Pictures of the planned new building, which may be built on the former American Pipeyard near First Street and the North Platte River, show large windows with walls of brick and stone.

Much of the second floor will be windows, providing views of Casper Mountain. There may be a children's area in the back opening to a park and the North Platte River.

Contact city reporter Christine Robinson at (307) 266-0639 or christine.robinson@trib.com