An atrium was an attached part of a building. It could be built with glass walls and roof.
The Vulcan monastery at P'Jem featured an atrium as first room for entrance. The room was filled with several artifacts and statues, had a bench and several dividers as well as a huge round window. The atrium was the place of the sanctuary where visitors were greeted. In June of 2151, Lieutenant Malcolm Reed placed micro-charges behind a wall decoration depicting a face and detonated them to overwhelm the Andorians. (ENT: "The Andorian Incident")
The "main atrium" of the monastery was built and filmed on Paramount Stage 8. (
Tolen and Lidell Ren's house on Banea featured an atrium decorated with plants and flowers. In 2371, Lidell was smoking inside the atrium. (VOY: "Ex Post Facto")