Police say the cause of the fire at the GardenBarn plant supply business is likely to be accidental.
Wairarapa CIB Detective Sergeant Barry Bysouth said a fire investigator had "inspected the scene closely" but was unable to say it was deliberate.
"There is no obvious evidence of a deliberately lit fire and it's likely to be put down as accidental," he said.
Uniformed police had completed interviews at the scene of the fire on Sunday but detectives would not be assigned to the case, Mr Bysouth said.
Fire investigator Stu Law said inquiries were continuing.