Auckland City Mission says a fire at its James Liston Hostel is believed to have started accidentally.
The mission said the building's smoke alarms and sprinklers went off when the fire broke out in Howe Street, Freeman's Bay on Sunday afternoon.
The blaze came just weeks after a fatal fire at the Wellington hostel where many vulnerable people lived. Five were killed.
City missioner Helen Robinson said people were evacuated quickly and no one was hurt.
"I was alerted yesterday afternoon about three o'clock to say that there was a fire at James Liston Hospital. Gratefully… a complete contrast to what happened at Loafers Lodge, some really good building processes. Smoke alarms were activated, sprinklers went as well and then also really good people processes.
"James Liston was staffed by a number of staff 24 hours a day, 365 days a year, so we were able to evacuate people quickly and safely.
"Incredibly grateful again for Fire and Emergency for their quick and amazing response that literally made a real difference."
She said the fire was believed to have been sparked by a charging device that was left on a bed - a "genuine accident".
Robinson said there was a lot of fire and smoke damage to the room where the fire started, and eight other rooms got drenched in water from the sprinklers.
Most people were able to return to their room Sunday evening.
"We'll see today what - if there is any - long-term water damage beyond that one room. But actually, the news is that it was relatively contained to one room."
She said it was a shock to hear, coming so soon after the Loafers Lodge fatal fire.
"It's a call that no individual ever wants to receive… it really does call on all of us to have really good building systems and really good people systems so that when, if it does occur, that we can respond quickly."