The purpose of this study is to evaluate and analyze the Tung Song Hong (TSH) Corehousing project in Bangkok provided by the National Housing Authority by looking at the residents' profile and extention process of their houses. It was found that residents' mobility is not high and they have been created their living environments, extended and remodeled their houses step by step under their management. There are common spatial pattern of the houses, even original corehouses varied. TSH project played an important role to give an opportunity for the residents on their living environmental formation process.