PAK’nSAVE in Invercargill is set to increase in size by 38% as the supermarket undergoes a two-year refurbishment.

The total size of the store on Tay Street will increase by 1600 square metres, and Foodstuffs South Island GM for Property Roger Davidson said it would be spread out over the two-years to ensure customers can continue to "shop in comfort".

"Invercargill was the first PAK’nSAVE to open in the South Island in 1988, and this investment further emphasises our commitment to the wider Southland community. The store will provide customers with a shopping experience equal to what is available in other regions," he said.

Mr Davidson said the refurbished supermarket will feature new retail fixtures, an expanded grocery range and "ongoing top quality fresh foods all in a pleasant shopping environment" and the company would "do our level best to minimise disruption to customers" during the refurbishment period.