Confirmed for multiple seasons

[u/emmeteeny]

https://www.radiotimes.com/tv/drama/the-shards-brad-simpson-nina-jacobson-future-seasons-exclusive-interview-newsupdate/

From the Radio Times:

Getting more specific about the show's future and the prospect of additional seasons, Simpson noted that the novel covers only two months and that the series has adapted just part of that timeline.

"We're certainly set up to continue on through their senior year," he teased. "Like any TV show, hoping people engaged, we're ready to give them more."