Topeka ? Building a new power plant for the Kansas Statehouse and four nearby state office buildings would cost $3.3 million more than previously estimated, officials said Tuesday, leading a Republican legislator to call for GOP Gov. Sam Brownback’s administration to reconsider plans.

The new plant would contain equipment for heating and cooling the five buildings, and the state Department of Administration wants to build it on the site of a parking lot north of the Statehouse. It would replace an existing one in a sixth building, the Docking State Office building to the west of the Capitol. The department hopes to finish construction by the end of next year.

The department plans to demolish the Docking building after the new power plant is completed, saying it wouldn’t be cost-effective to keep the office building open. The state built Docking in the 1950s and the department estimates that it needs between $75 million and $100 million worth of maintenance.

Mark McGivern, director of the department’s Office of Facilities and Property Management, told a legislative committee that the new power plant is now expected to cost $16.3 million instead of the $13 million previously estimated. He said potential contractors became less eager to do the project as the economy improved, and an outside firm hired to project costs simply underestimated.

McGivern said the annual costs of running the new power plant will be cheaper than keeping Docking open. Also, he said, the department has taken steps to lower the costs of demolishing the office building so that the cost of both together will be between $19 million and $19.5 million, instead of between $17 million and $18 million.

“We looked at it as a single project,” McGivern said.

McGivern disclosed the revised figures to a joint legislative committee that reviews state construction projects. Republican Rep. Mark Hutton, of Wichita, asked the department to reconsider an idea it has rejected — keeping the existing power plant while dismantling the rest of the office building around it.

“The question of the energy center is up in the air, whether we build a new one or preserve what we have,” Hutton said.

Democratic Sen. Laura Kelly, of Topeka, predicted the costs associated with the department’s plan will continue to rise until it exceeds the $30 million estimate for the project she favors. She wants to shorten the building from 12 above-ground stories to three or four, for state offices.

As for the department’s plan, she said, “I’ve never thought it was worth doing.”

But McGivern said building a new power plant allows the state to implode the Docking building, rather than taking it down floor by floor.

The state plans to finance the new plant through a private bank loan, paying the debt off over 15 years at 2.33 percent interest in a lease-to-own arrangement.