Firefighters attended a spate of suspicious fires in Christchurch overnight.
An abandoned house was badly damaged by fire on Azure Pl in Burwood about 9.30pm.
A Fire Service spokesman said the house had been "red-zoned" due to earthquake damage.
The fire was being treated as suspicious and police were investigating.
Between 2am and 4am, firefighters were called to between six and eight rubbish fires in the Woolston area.
