However, the building's official re-opening will not be till early next year once all the tenants are in, she said.
Jewellery and speciality retailer Tiffany & Co will spread across the entire ground floor of Australis house, Hull said, while Chanel will be in the neighbouring Nathan Building.
In the four levels above, a number of commercial tenants will occupy space including two firms of lawyers: Duncan Cotterill and Anderson Lloyd.
Changes to the Australis Nathan Building were designed by Peddle Thorp Architects and the head contractor is Hawkins Construction.
A number of original building features have been reinstated in the buildings. Modern amenities have been added such as new bathrooms, toilets and a lift.
A new luxury cafe, restaurant and underground bar are planned to open in the Nathan Building soon.
All the works are designed to integrate the two historic buildings into one, creating bigger floor areas and more expansive space for the tenants.
Last year, Glen Schlehuber, Tiffany's Australian vice present and managing director, told the Herald of some of the items to be sold.
"The new store will house a large selection of iconic Tiffany collections, such as diamond engagement rings for which Tiffany is renowned around the world, as well as fine, gold and sterling silver jewellery. In addition, it will feature the acclaimed creations of exclusive Tiffany designers Elsa Peretti, Paloma Picasso and Jean Schlumberger, as well as signature collections such as Tiffany T and Tiffany Atlas, watches, gifts and leather accessories," he said last year.
"New Zealand is a market that we have been visiting for many years; we have very loyal New Zealand clientele who shop with us in Australia, so it was really a matter of finding the right location and environment for our brand. We truly believe in the New Zealand market and as such we have entered into a long term lease with Cooper and Company," Schlehuber said.