The Auckland Harbour Bridge's Shelley Beach Road off-ramp has been opened after it was closed for 12 hours after a nearby house fire early on Sunday morning.
Three firetrucks responded to a three-storey villa in the upmarket St Mary's Bay just before 2am.
At its peak, six crews were fighting the blaze as it sent plumes of smoke over the nearby motorway.
No injuries were reported, and the fire was extinguished by 2pm on Sunday.
Investigators were working at the building on Sunday afternoon.
Firefighters said the villa suffered serious structural damage in the fire and there were risks from falling debris.
The whereabouts of the residents was unknown, with some neighbours believing they were overseas.
Fire and Emergency could not say if the cause of the fire was suspicious.