Shipping containers and wharves have given way to steel towers, glass, and glossy marble in the lobby of the first of the new Barangaroo South towers to be opened.

The lobby houses the first new retailer at Barangaroo, Toby's Estate coffee bar.

"Only a few weeks ago it was a world away. It's been my baby, mate, my second home," said Toby's Estate business partner Ali Akl.

"Having our very own cafe in Sydney's iconic location that is Barangaroo to showcase what we do, for us it's been groundbreaking," he said.

Barangaroo South Lend Lease managing director Andrew Wilson said the retail opening brings back Barangaroo's merchant history.

"It's great to have a new type of commerce coming on to the site. We've had ships here, we've had merchants. The street outside us here is called Mercantile Walk. It's all about merchants trading and what better example than Toby's opening today," Wilson said.

The three-storey lobby housing the retailer boasts eight-and-a-half million tiles, imported from Spain,  which form a mosaic wall, alongside Cairns marble making up benches and planters.

Westpac and St George banks will be the first commercial tenants in the building. At completion, the area will house 23,000 office workers and 2500 residents.

Barangaroo South will eventually be home to 90 retailers, about 60 of which will be food and beverage retailers.

"You'll have Campos in eye's view. You have Coffee Alchemy. There have been a few whispers of some new cafes coming on board," Mr Akl said.."

Tower 3 will be finished in mid-2016, while Tower 1 will be completed at the end of 2016. The first residential apartments at Barangaroo will be handed to tenants before the end of this year.