The Westfield San Francisco Centre could be getting more office space as part of a $75 million renovation project.

The plans include 49,999 square feet of office space on the mall’s seventh and eighth floors, replacing retail, storage and meeting space in the wing at 5th and Market Streets, according to Westfield. The project would add three new terraces showing views such as Powell Street’s cable cars and include a new glass facade and other renovations, the company said.

The proposal comes as malls across the country are reconfiguring their spaces as ever more consumer purchases move online. Large national retailers like Macy’s and Toys R Us have been closing stores, and smaller businesses like Berkeley’s Body Time have cited tough economics as a factor in shutting doors.

In 2014, the Westfield in San Francisco announced it would become one of the first local malls to add Bespoke, 35,000 square feet of co-working, demonstration and event space. Other malls, including Vallco in Cupertino, are also planning to building office space.

Larry Green, Westfield’s senior vice president for U.S. Development, said the renovation is an example of how his company continues to invest in the “ongoing vitality and productivity of its centers and the communities it serves.” Besides stores, Westfield offers a mix of other options such as entertainment, dining, co-working spaces and cultural events, he said in an email.

The project is a joint effort by the mall’s owners, Westfield and Forest City Realty Trust and would need the approval of the city’s planning commission.

The Westfield’s plans were first reported by the San Francisco Business Times.

Wendy Lee is a San Francisco Chronicle staff writer. Email: wlee@sfchronicle.com Twitter: @thewendylee