Social networks, social cohesion, and place attachment are positive social impacts that can stimulate people’s quality of life. High-rise apartment buildings are often criticized for their negative social impacts, such as social isolation and low levels of interaction and social cohesion. However, there is still insufficient empirical evidence on the relationships between neighborhood social networks, social cohesion, place attachment, and loneliness of high-rise apartment residents and how they are affected by the physical environment and neighborhood satisfaction. This study uses structural equation modeling (SEM) to investigate these relationships using data collected in four high-rise apartment complexes in Hanoi, Vietnam. While the number of neighbors in someone’s social network is found to stimulate social cohesion, which can foster neighborhood attachment and reduce feelings of loneliness, the possibility of improving these social impacts is affected by urban contexts, site properties, and the ability to provide communal spaces within and surrounding the buildings.