A toilet block and storage area nearby were also extensively damaged.
Two children, aged 3 and 6, playing with a lighter sparked the fire in a pile of mattresses.
Marae committee chairman Dave Scott said the area was cleared and all that remained was the concrete block.
"The carvings were so badly damaged it was decided to bury them along with the marae ashes on the grounds," Mr Scott said.
"The feeling is there needs to be a brand new building with new carvings to be done.
"We are looking forward to getting it all under way."
He said the marae was under insured and while they were to receive nearly $300,000 they would need significantly more to complete the new building.
The shortfall would hopefully be made up of grants they were able to obtain for the rebuild.
A master carver had also be spoken to about the replacement carvings.
"We are slowly coming together," Mr Scott said.
"There was some ill feeling in the beginning but the more we talk and plan we are coming together as one."
He was unsure as to when building might start as plans had to be completed and more funding sourced.
"People want the building up as soon as possible but it does take time."