A Fire and Emergency NZ spokesperson said firefighters attended a well-involved two-storey dwelling on Colombo St.
At least four fire appliances were called to the scene from four stations - Christchurch City, Ilam, Spreydon and Wigram.
Firefighters could be seen fighting the blaze with flames visible from the street.
A neighbour told Chris Lynch Media the property had become a magnet for homeless people.
He said it was the second blaze at the address. The neighbour says he had urged the city council to mow the lawns of the property.