East Tennessee Children's Hospital began work Tuesday on a major expansion project.

The new $75 million building will house a 44-bed Neonatal Intensive Care Unit and Surgery Center at the corner of White Avenue and 21st Street, along with more parking and rooftop gardens. It will be connected with the current hospital through pedestrian bridges that will also include extra space for families to gather, children to play, and dedicated consultation rooms.

Click here for more on the expansion and to see more artist's renderings

The five-story building will give Children's an additional 245,000 square feet of operating space, designed to make patients and their families feel more comfortable.

"At the core of who we are is working with our families and providing family-centered care. We understand that the family is an integral part of everything we do. We have to give them the facilities and environment that allows us to help us help their child," said Keith Goodwin President and CEO of ETCH.

Construction is expected to last about two years. When the new building is finished, officials plan to renovate the existing hospital.