Catholic charity Caritas Australia has told Premier the buildings most likely to have remained standing after the devastating winds are churches.
"Churches are the most stable structures in communities where thatched housing is the predominate form of housing.
"They will often go to churches to seek refuge and we have heard stories of communities going to these churches and seeking refuge," said Stephanie Lalor, Pacific Programmes Manager at Caritas Australia.
Aerial surveillance has shown some communities flattened and the country's president has said Cyclone Pam destroyed or damaged 90% of the buildings in the capital of Port Vila.
Tens of thousands of people have been made homeless and at least eight people have died.
Unicef estimates 54,000 children are among those affected by the cyclone.
Information from other islands is available because most communication links are still not working.
Stephanie Lalor added: "We have established contact with the Bishop of Vanuatu, he is on his way back into the country at the moment.
"I think it's very difficult to really get a sense of what the needs are and certainly we'll work closely with the Catholic Church in country as it starts to plan its response."
President Baldwin Lonsdale said: "This is a very devastating cyclone in Vanuatu. I term it as a monster, a monster.
"It's a setback for the government and for the people of Vanuatu. After all the development that has taken place, all this development has been wiped out.
"So it means we will have to start anew again."
Caritas said the immediate needs were food, shelter, cooking utensils, hygiene kits and access to clean water.