The location of this project is in Lingzhao New Village of Pudong District, Shanghai, which is consist of public-owned apartment buildings constructed in the mid-1990s in the central area of Sanlin Town. This project, with an area of 48㎡ and a small yard, is on the ground floor and of poor indoor natural lighting. The residents are a mother and her son, together with 12 cats and 1 dog. The project is designed to set up an organized pattern of “High density co-living of men and pets”, for example, the specially-designed “Marseille Apartments of Cats”. The project is also designed to provide living and playing space for both men and pets, which is visible to, yet isolate with each other. Meanwhile, the project is designed to solve the common problem of lighting and humidity of old Shanghai public-owned apartments. When facing compressed living space, especially in crowded urban cities, people have been urged to seek for bigger apartments and higher income and have become anxious with peer pressure. By “the elegant co-living of men and pets in the 48 ㎡ apartment”, the design has conveyed an attitude of hopefulness in whatever difficulties by using existing resources and adopting reasonable design.