Plans for a new building at the Westwood Hills Nature Center at St. Louis Park are moving forward — albeit at a higher cost.

The center, which would replace a crowded, aging building and house a variety of indoor activities, was estimated to cost $12 million earlier this year. But the price tag was raised by $500,000 after soil conditions were found to be “much more mucky and unsuitable than originally anticipated,” requiring a stronger building foundation, according to city documents.

The new center would be five times larger than the current space. It would include classrooms, an exhibit room, offices, three raptor cages and outdoor decks looking out on the woods. The project would also double the amount of parking spaces.

St. Louis Park Council Member Thom Miller has voiced concerns about the rising price of what he called a “very deluxe interpretive center,” saying the city should be financing other things, including affordable housing.

“I just think we have to consider really what we spend money on: our needs vs. our wants,” he told the council in May.

Miller said he would continue to vote against the project as it moves forward.

The rest of the council remains supportive. They have praised the sustainability components of the new building, which would have solar panels on the roof that, over time, will generate all the energy used.

“We’re going to model responsible resource management,” Council Member Tim Brausen said. “It’s really our chance to lead in this perspective.”

Construction bids are expected to go out in the fall and be approved by the end of the year, according to Cindy Walsh, the city’s director of operations and recreation. Crews would begin construction next spring.

The existing building would remain open during construction. It would be demolished once the new center is finished, which Walsh expects will be in fall 2020.

The Westwood Hills Nature Center, which overlooks Westwood Lake and is an 11-minute drive from downtown Minneapolis, draws about 36,000 visitors a year, according to staff.