Flats building is a building that is functionally structured in horizontal or vertical direction. Flats building serve as shelter, equipped with shared parts, body joint and common ground. The problem on flats in Jakarta is the lack of designers attention of the building in regard thermal comfort inside the unit towers. The purpose of this study was conducted to determine whether the standards in order to achieve thermal comfort in a flats building. In addition, this study aims to determine whether the Cinta Kasih Flats and Cigugur Tengah has met the standard of thermal comfort. This needs to be investigated because there are a lot of flats in Jakarta are still not meet the standards of thermal comfort of a building. This research is useful to be able to provide information about the thermal comfort of a building standard. This study is also useful to be able to determine and quantify thermal comfort in flats building. Methods of research conducted by gathering the data is done by searching through books, journals, and internet pages. Data obtained an international standard data how to achieve thermal comfort in flats building. In addition, the data collected about the factors that affect thermal comfort in an apartment building. These factors include ventilation, building height, the lighting entry, and building materials. Once the data search and collection data is complete, the authors will conduct an analysis of these data. Collecting data on case studies will also be conducted to find out about what things are there in the flats that can affect thermal comfort in it.