Combining these three characters gives you a very literal meaning: “a room (室) for storing (储) and hiding away (藏) things.”
While `储藏室` is a practical term, its prevalence and form speak to modern Chinese living conditions. In the past, with smaller living spaces in dense urban areas, dedicated storage rooms were a luxury. Storage was often integrated into furniture like large cabinets (柜子, guìzi) or chests. The concept of a separate `储藏室` became more common with the construction of modern, larger apartments and houses, reflecting a rise in consumerism and the need to manage more belongings. A key cultural comparison is with the American concept of a “basement,” “attic,” or “garage.” These are architecturally specific parts of a standalone house. In China, where high-rise apartment living is the norm, a `储藏室` is a more universal concept. It is often a small, windowless room, or sometimes even a designated caged-off area in a building's basement level, sold or rented along with the apartment. It highlights the high value placed on efficient use of space in populous urban environments. The modern Chinese obsession with organization and tidiness, influenced by figures like Marie Kondo, often centers on making the best use of one's `储藏室`.
`储藏室` is a neutral term used in a wide variety of everyday situations. It's neither overly formal nor slang.
The connotation is purely functional. A large, well-organized `储藏室` is seen as a positive feature of a home, while a messy one is a common source of domestic complaint.