In Indonesia, Sri Lanka and India, the countries hardest hit by the killer waves, land rights issues, a shortage of construction materials and government indecision initially slowed efforts to get survivors out of emergency shelters.
The tsunami that swept across the Indian Ocean left at least 216,000 people dead or missing in 12 countries, the majority in Indonesia's Aceh province.
Roads and ports were swept away, making it hard to get to some of the most devastated areas.
As result, only 20 percent of the 1.8 million people displaced by the tsunami are in permanent housing, Britian-based Oxfam International said as it and other aid organizations released reports reviewing their work so far.
While most of the displaced are staying with host families, tens of thousands still live in crowded tent camps, where they are pounded almost daily by monsoon rains, and frustration is starting to mount.
But Oxfam noted that even rich countries struck by natural disasters can struggle for years to rebuild, citing earthquakes in Japan and Iran, any of the obstacles that were blocking reconstruction have since been removed.
"We had certain expectations about how quickly we'd be able to move forward and we haven't met all our marks," said Paul Dillon from the International Organization for Migration, which is building transitional homes.
"But at the same time, we're very well placed for 2006," he said. "We're going great guns."
Foreign government and private donors pledged more than $7 billion for reconstruction and rehabilitation across tsuanmi-affected countries and thousands of international aid workers poured into the region to help.
While they succeeded in setting up emergency shelters quickly, saving thousands of lives, many did not have the experience or expertise to carry out mass projects to construct homes, Oxfam said.
"Few humanitarian agencies had ever faced need on this scale, spread over such a wide area," said the group, which has helped provide clean water and sanitation to survivors, clear agricultural land and revive livelihoods.
Some of the things that stalled efforts to get people out of tents, barracks and the homes of family and friends were unavoidable, Oxfam said, noting that land in Aceh that once housed 120,000 people was permanently submerged under the water.