Activists and people who face housing problems have urged the United Nations Secretary-General Ban Ki-moon to push the government to solve the problem of eviction in urban communities and approach development policies which take into account human rights.
The call came at a gathering of 1,000 members of the Four Region Slums Network (FRSN) and P-Move, a civic group working on land rights issues, in front of the United Nations Economic and Social Commission for Asia and the Pacific (Unescap) headquarters in Bangkok.
The gathering was held to mark Monday's World Habitat Day 2015.
"Housing problems are caused by development focused only on extreme economic growth. That kind of growth brings large amounts of wealth to small groups of people while pushing others to the edge," said Jamnong Nupan, president of the FRSN.
The FRSN's survey found there are 86 communities, equivalent to 8,100 families or 34,000 people, which have been forced to relocate for development projects, including transport projects.
Many rural communities have also experienced the same fate as a result of state development projects including mining concessions, power plants, railways and road expansions, said Mr Jamnong.
Forest reclamation policies also made local villagers, who lived in the forests before they were declared state forest zones, homeless.
Mr Jamnong said the government lacks mitigation plans for affected people, and local people have little control over their decisions affecting their communities.
"On World Habitat Day, we call on the UN to ask governments to pursue development policies in line with the right to secure homes," he said.
The government should provide homes for the poor, such as the Ban Mankong housing project, he said.
Mr Jamnong spoke specifically about locals from the southern provinces who were accused of encroaching on state forests.
Their rubber plantations were cut down by government officials who blamed them for forest encroachment.
The rubber farmers had occupied the plantation land long before the national forests were declared, Mr Jamnong said.
After handing a letter to UN Habitat representative Liam Fee, the activist groups moved to Government House to hand a letter to the Prime Minister's Office minister, ML Panadda Diskul.
The activists called on the government to support projects to improve peoples' habitats, and allow local decisions over development projects which stand to affect livelihoods.
On Friday, the UN released remarks from Mr Ban saying the theme of World Habitat Day 2015 is "Public Spaces for All".
Frequently overlooked and undervalued, public spaces are increasingly being seen as the vibrant, beating hearts of the world's cities, which are today home to half of humanity, Mr Ban said.