CHAPEL HILL - Andrea Knight brought her children, 3-year-old Ann Marie and 6-year-old Alexander, to Kidzu Children's Museum on Thursday afternoon to help them burn off some energy indoors.

"It's a good day for that," she said. She takes them there six to 10 times a year because she thinks it stimulates their minds to interact with other children and have unstructured playtime.

The Kidzu Children's Museum in downtown Chapel Hill offers one arts-and-crafts program and one exhibit at a time. It's visitors often have to get on a waiting list.

That is why the museum is planning to expand. So is the ArtsCenter in downtown Carrboro.

The two nonprofit groups both say they "are bursting at the seams" and need to find a new facility soon before they begin their major fundraising campaigns. They are in preliminary discussions to share the soon-to-be redeveloped ArtsCenter building.

Main Street Properties, which owns the 300 block of East Main Street in Carrboro, except for The ArtsCenter, plans to redevelop the entire block, bringing a hotel, a parking deck and more restaurants and shops.

The ArtsCenter building is scheduled to be redeveloped later this year or early next year, along with the rest of the block. Executive Director Jon Wilner envisions the new ArtsCenter as five stories tall and near its current location. It might share the space with a magnet school for the arts.

Kidzu would like to stay in the Chapel Hill-Carrboro area, in or near downtown. Cathy Maris, executive director for Kidzu, said one potential site is the Franklin Street post office building.

The museum has been open for nearly a year and a half and has had more than 29,000 visitors in its first year, Maris said.

"For us to be a part of the community, it's absolutely essential that we have a new home," she said. "It's a real challenge to successfully meet the needs of children of all ages when we have such little programming space and can only have one exhibit at a time."

If they decide to share a building, the two groups would share space but not programs. Still, being in the same building could lead to inevitable synergy, both Wilner and Maris said.

Currently, Kidzu serves children up to 8 years old. The ArtsCenter primarily serves children 6 and older. Both are educational organizations focusing on families and children, on creativity and on sharing the talents of local artists and performers with children, Maris said.

"It would create an instant destination for families and children," Wilner said. "And if we are able to involve the school district as well, then that much better."