Costco is planning on opening new stores in Sydney, Brisbane and Melbourne in the coming year. Courtesy: A Current Affair/Nine Network

COSTCO Australia’s boss has revealed where some of its future stores will be built as the popular bulk discount retailer expands.

Currently, the retailer has eight stories across Australia, but in the year ahead, they plan to open three new buildings.

One will be opened in Marsden Park in Sydney, NSW, another will be in Brisbane, Queensland, and another will be opened in Victoria in the suburb of Epping.

Costco Australia’s Managing Director Patrick Noone told A Current Affair that after opening in these locations, they hope to look at “second-tier cities” where they can open in locations such as Newcastle, Wollongong and Darwin.

“They’re the places for the next growth for sure,” he said.

After making $1.3 billion in sales, Mr Noone said it could be attributed to the company’s “efficient business model”.

“We have an extremely efficient business model. If you look at everything it’s on a palate, we have an open framed ceiling, we have concrete floors, we have very low costs and overheads and we continue to drive prices down rather than drive prices up,” he said.

Mr Noone said he was also hoping every Costco in the future will have a petrol station on site to continue to offer a cheaper alternative to consumers.

The first Costco petrol station was opened in 2014.

“Every Costco in the future will likely have a petrol station on site. The growth has been spectacular,” he said.

The retailer has become an instant hit with shoppers, who are charged an annual membership fee of $60.

The sell everything from petrol to fresh food, hardware, furniture, liquor, electronics and more.

Brian Walker, CEO & Founder of Retail Doctor Group, said Costco’s competitors will be watching their progress.

“I think by about 2020 I’d be surprised if we weren’t looking at 30 to 40 units across the country,” he told ACA.

“Coles and Woolies are going to be watching them, but let’s see them get at 20 or 30 sites then I think it’s game on.”