Physical characteristics of residential areas affect many aspects of living sustainability, including the environmental behavior of residents. Based on the policy issued in China in 2016, the guideline of transforming existing gated housing blocks into open mode is being gradually implemented in some cities. However, the transforming of boundary walls and internal roads has changed the living environment such as the open space that residents have been accustomed to and has affected environmental behaviors correspondingly. From perspectives of spatial types and environmental behaviors, this research compared an open housing block (which is reconstructed from gated one) with a comparable original gated housing block. The Behavior Mapping Method was used to capture environmental behaviors in two housing blocks; factor analysis and cluster analysis were used to extract spatial characteristics and classify spatial types; and finally differences between the open housing block and the gated housing block were shown by comparing the distribution of environmental behaviors in each space type. The results indicate that the presence or absence of the enclosing walls affects the division of space types and environmental behaviors in housing blocks. For gated housing blocks, spaces with strong privacy attract various types of activities, which are overwhelming in categories and the number of people, while in the open housing blocks, this situation is not as obvious as in the former.