Fire crews were called to the old Newcastle Post Office building about 9.44pm on Thursday night.
On arrival at the scene they found a pile of rubbish on the lower balcony alight. It took crews just 10 minutes to get control of the blaze, which caused smoke damage to the exterior of the building and destroyed some of the boards being used to secure the site.
“We had a strong initial response to the emergency call, especially because of the size of the building,” a Newcastle Fire and Rescue spokesman said.
“Once on scene we had two pumps and a rescue crew and got control of the fire. Once it was out we made sure it hadn’t spread any further.”
Fire and Rescue NSW believe people using the site at the time could have a connection to the small fire. The incident has now be handed over to NSW Police.