
The blaze broke out on Hampshire St in Aranui about 5.07am on Thursday.
Early reports suggest no one was in the house at the time of the fire.
Stuff has reported the building is a block of flats which is now being guarded by police.
A Fire and Emergency NZ spokeswoman said a fire investigator is expected at the property later this morning to determine the cause.
She said the small fire is not believed to have caused significant damage.
Fire crews from the Christchurch central and Anzac stations attended.
A police spokeswoman said they were still on the scene at 7.45am.
"The circumstances of the fire are under investigation."