On arrival, crews found a small fire on the fifth level, he said.
Police were then called to assist, as the circumstances surrounding the blaze were dubbed suspicious.
No injuries were reported, he said.
This is the not the first fire reported at the new site since it opened its doors early last year. A blaze was reported in October.
Auckland City Mission’s new building - HomeGround Te Tāpui Atawhai - includes 80 permanent apartment homes for people on the social housing register.
The $110 million building has 10 levels and is the country’s tallest wooden block.
Police have been approached for more information.