The Westfield UTC mall will likely be a different place in 2017.

Construction has started on its $500-million expansion, which will add 395,000 square feet to the 1.1-million-square-foot facility. Australia-based mall owner Westfield also has the option to add an additional 300,000 square feet of retail and 300 apartment units.

A first phase of the renovation is already completed. It cost $180 million in 2012 and included the conversion of a former Robinson’s-May department store into a building that now houses Forever 21, ArcLight cinema and 24 Hour Fitness.

This new addition will include a new Nordstrom, event space and public-transit access, among other features.