The Fire Service says it will cut back its emergency response to some callouts to reduce traffic snarl-ups in major centres.
The service's national commander, Mike Hall, says up to six trucks are currently sent to check automatic alarm activations in buildings with sprinklers.
From the end of next month, just two trucks will be sent to most alarms and more crews will be sent if a 111 call is confirmed.
Mr Hall says automatic alarms in high-risk buildings, such as hospitals and flammable goods stores, will still draw a full brigade response.
He says 25,000 automatic alarm activations were recorded in buildings with sprinklers over five years, but only nine of them involved serious fires.
