A tower crane, construction crew from Naylor Love and subcontractors are now at the Zara site where air conditioning equipment was this week being installed.
But Gudgeon said not all the new space would be used by Zara.
"We're doing a bit of future proofing in anticipation of the next stage of the retail expansion. We're looking at a second level - a retail galleria. So while we're building for Zara, we are obviously taking into account our plans with what will happen above Zara and it makes sense to do that construction now.
"Ultimately, there will be another level of retail across a lot more than just Zara," Gudgeon said, describing a longer term plan to add a further 2ha of floor space to the mall.
"We're not committed to that 20,000sq m yet," Gudgeon said. The floor above Zara would bring a further approximately 1000sq m of space to the mall," he said.
Total Sylvia Park trade area retail sales were $11.2 billion in the June 30 2015 year, Kiwi reported. That is projected to grow 4.7 per cent annually to reach $23.5 billion by 2031, the business calculated.
We're doing a bit of future proofing in anticipation of the next stage of the retail expansion.
The mall has about 4000 on-site car parks and is within a 10-minute drive for 440,000 people, Kiwi said in its latest annual report.
Kiwi described Zara's reach:
"Zara opened its first store in 1975 in A Coruña (Spain). It now operates in 88 markets with a network of more than 2000 stores ideally located in major cities. Its international presence clearly shows that national borders are no impediment to a shared fashion culture. Zara pays special attention to the design of its stores, shop windows and décor, and sites them in the best locations in major shopping areas."