Fire investigator Craig Bain said it appeared the house had been empty for about 18 months and it had no power.
“We have no idea how it [the fire] started but it was definitely deliberately lit,” he said.
Police are now investigating and have urged anyone with information to come forward, quoting job number P059865438.
The damaged property is next to the home where 61-year-old Hoani Reupena-Tuoro, also known as John Reuben, died after a fatal car and house fire on April 29.
A man has been arrested and charged with arson for that case.
Bain said it would be up to police to investigate if there is a link between the two fires, but he could not see any connection other than the location.
Thomas St has a number of empty Kāinga Ora houses, with redevelopment in the consenting stage.
Police did not answer questions about whether the two incidents were linked.
Kāinga Ora Northland regional director Jeff Murray confirmed the fire was at a Kāinga Ora home and believed to be deliberately lit.
He confirmed the agency owns a number of Thomas St homes, including some vacated as they were proposed for future redevelopment.
Murray would not comment on security for the empty homes: “Security arrangements for vacant properties are considered on a site-by-site basis and are not something we publicly comment on for safety reasons.
“Redevelopment of our Thomas St homes is under assessment while we confirm our social housing projects for the next two years, with a focus on priority locations and best value for money,” he said.
Denise Piper is a news reporter for the Northern Advocate, focusing on health and business. She has more than 20 years in journalism and is passionate about covering stories that make a difference.