RIKUZENTAKATA, Japan — Yukiko Yamaguchi wants to go home.

But like more than 400,000 others staying in shelters since a powerful tsunami plowed through their homes 10 days ago, the 73-year-old has no idea when she’ll be able to. Rebuilding Japan’s northeast coast is expected to take years, and the monumental effort is not even close to beginning.

Instead, another phase is slowly getting off the ground: the construction of prefabricated homes as temporary housing for the displaced.

“We’re anxious to leave here,” Yamaguchi said, sitting with her husband on a woven mat in a middle-school gym that has been their home since the town of Rikuzentakata was flattened by the raging torrent of water on March 11.

Today, construction workers outside the school screwed in the corrugated aluminum rooftop of one of the first temporary homes to spring up: a metal-sided box raised on wooden stilts above a muddy soccer field.

The house is one of 135 that will be built at the school by the Iwate provincial government, and one of thousands that will go up in the coming months outside other shelters scattered across Rikuzentakata’s hilly outskirts. Residents will likely stay in them for a couple of years until more permanent homes are ready.

“It’s simple and easy to feed people,” Yamaguchi said, referring to the meals prepared daily at her shelter, where laundry hangs in classrooms. “But the question everybody is asking is, when can we go home? We want to know how they plan to rebuild this town.”