The blaze caused “extensive damage” to the block on Mentor Lane, which sits behind the main Cannons Creek shops late on Sunday evening.
Fire and Emergency New Zealand was alerted to the fire shortly after 11pm Sunday.
More than 40 firefighters were greeted by a building which was well-involved in fire, according to shift manager Jan Wills.
One fire truck was still being used to dampen down hot spots on Monday morning.
Wills would not be drawn on whether the blaze was suspicious, but confirmed a fire investigator would be at the scene on Monday.