The 42-year-old man, identified only as Hendra, emerged alive from the wreckage on Saturday, a day after rescue workers formally called off the search for survivors, saying it was unlikely anyone could survive for more than four days.
At least 1000 people are confirmed to have died in the 8.7-magnitude earthquake on several islands off Sumatra.
Most of the deaths occurred on Nias island.
Hendra was found after labourers, employed by the family to look for survivors in the rubble of his three-storey house, heard him calling out for help and water.
They alerted the police who fetched Singaporean and Indonesian rescue teams that spent seven hours cutting through a thick layer of broken walls and roof.
CW Ong, the head of the Singapore rescue team, said he saw no corpses in the space where Hendra was found.
"It was the most challenging operation we have ever taken part in," he said.