How often do sandwich apartments typically have floors?

Sandwich apartments are designed with a unique structural setup that typically involves a separation of living spaces between floors. The correct choice reflects that these apartments usually contain floor layouts that alternate, with a pair of units located directly above and below each other. This often leads to a configuration where there are living spaces separated by every third floor, allowing for ventilation and soundproofing benefits.

In a sandwich apartment, two floors may house living units, but the third floor is often void to enhance the apartment's sound insulation and accessibility for services such as plumbing and air conditioning. This design reduces direct noise transmission between units and improves the overall living environment, which aligns with urban planning and architectural trends in multi-family housing.

Thus, the understanding of sandwich apartments being typically organized every three floors provides insights into their design and functionality in urban settings.