Police are investigating an arson at Risingholme Community Centre on Cholmondeley Avenue, Christchurch.
It is believed the fire started around 8pm yesterday.
Police are asking if anyone has information regarding this to contact either senior constable Danelle Asher 03 363 7566 or your local police station.
Firefighters were called to the historic community centre shortly after 8pm yesterday, as a small fire spread very quickly through the building.
The centre was substantially damaged, with the roof of one wing collapsing.
Crews were rotated through the night, staying on-site to dampen down hotspots this morning.
Senior fire shift communications manager Darryl Ball said they did not yet know the cause.
He said it quickly took hold of the very old wooden structure and they needed around eight fire trucks.