The Warehouse will remain open during New Zealand's four-week isolation period.

In an announcement to the sharemarket, The Warehouse says it's a provider of key consumer goods for New Zealanders.

Online stores and The Warehouse Group fulfilment centres, servicing The Warehouse, Torpedo7, Noel Leeming and Warehouse Stationary, would also continue to operate.

"In the past two weeks the group has seen unprecedented demand for essential items across all our brands. Goods sold included essential items to prepare themselves for the mandatory isolation period of at least four weeks," says the retailer.

The Warehouse will implement new safety protocols across its 92 stores to protect staff and customers, including additional cleaning, leave and wellbeing support.

"We are working with New Zealand's two major supermarkets to submit to government personal protection equipment requirements and supply for our people," says the statement.

"Customers in store will be asked to adhere to new protocols including social distancing and limiting purchasing, in some cases, to two items per product."

The Warehouse had already implemented limits on high-demand products such as toilet paper, hand sanitiser and face masks.

During the level 4 lockdown, most retailers will be closed.

Supermarkets have been given special dispensation to remain open with some altered conditions.

This included reduced hours, face masks for staff and perspex at the checkouts.

The major supermarket chains, Countdown and Foodstuffs, have continued to call on New Zealanders to shop normally during the lockdown period.