An expert says owners of heritage-listed buildings are facing huge obstacles, and aren't getting the help they need.

It comes after a devastating fire at Christchurch's 110-year-old Antonio Hall on Friday.

The derelict building already had previous fire and earthquake damage. It has been out of use for over 20 years, and was a well-known spot for squatters and parties.

Christchurch Heritage Trust chairwoman Dr Anna Crighton told the New Zealand Herald "decades of neglect" was to blame for the devastating fire.

However, New Zealand Initiative chief economist Eric Crampton told Heather du Plessis-Allan we need to think about how to help these owners.

"You just hear stories like six year processes for deciding that a building can actually be demolished, and in the mean time you have it posing massive risk to anyone walking near it."

He says we should look at the obstacles facing owners, before we penalise them

"If you're the owner of a heritage-listed building and it's got some earthquake strengthening deficiencies, that can just be huge costs involved in doing any work on the building at all."

A teenager has been charged with arson in relation to the blaze.