Villages along Indonesia's tsunami-ravaged coast are filling up with modest new homes. But thousands are being torn down or retrofitted to withstand future earthquakes - slowing the pace of rebuilding.
The changes, which include adding steel reinforcements, shoring up shoddy brickwork and building pillars to stabilize large, open rooms, are expected to add US$25 million (euro18.6 million) to Aceh province's multi-billion dollar (euro) reconstruction efforts.
International and local aid organizations rushed to the scene after the 2004 earthquake and resulting tsunami that killed more than 230,000 people in a dozen countries, a third of them in Indonesia's westernmost province.
The initial focus, saving lives and providing emergency shelter, gave way months later to the massive task of building permanent dwellings for the half million made homeless in the seismically charged region.
But of the 70,000 brick and concrete houses already built, about 5,000 do not meet earthquake resistant codes and will have to be retrofitted, said Joseph Oenarto of Indonesia's tsunami reconstruction agency.
"In the first year following the tsunami, everybody was competing to build houses at high speed and not necessarily in terms of sound construction," he said, estimating the majority of houses in question were erected during that time.
The American aid agency Care recently said it was moving 142 families out of homes it built after an independent evaluation found they were not seismically safe.
The announcement follows efforts over the last several months by other organizations to retrofit or even scrap substandard housing and start over, including the U.K.-based Oxfam.
In some cases, the groups have brought on additional engineering staff or partnered with other organizations that have expertise in housing construction.
Though aid organizations had hoped to finish home-building by the year's end, they now say their work could spill into 2008.
"We have international standards to respect and that's why we're doing this retrofitting," says Oxfam's Christelle Chapoy. "It's moved to the top of the list."
International organizations have solved some of the other issues that initially marred building efforts - from termite-infested wood used to several cases of corruption by contractors.
But hurdles remain. Bricks, concrete and skilled labor are still scarce. The demand for wood is so high that, according to international environmental groups, illegally harvested timber is still being used in reconstruction projects.
There is no getting around the size of the undertaking.
"It's like building back Philadelphia or Liverpool, England," Chapoy said.
The skilled labor shortage complicates the effort to build 60,000 more houses. Some of the simplest features in an earthquake-resistant house - symmetrical, well-crafted walls and straight, reinforced columns - need trained foremen and laborers.
Indonesian officials are also pushing for more use of lightweight steel, tin and plasterboard, which make homes less cumbersome. But the move is meeting resistance from many Acehnese who consider concrete and brick the only materials worth using when building a home.