In which locations are plumbing systems prohibited from being installed according to code?

Plumbing systems are prohibited from being installed in elevator shafts and elevator equipment rooms primarily due to safety and operational concerns. Elevator shafts are designed specifically to facilitate the movement of the elevator car and are not intended to house plumbing systems. The presence of plumbing can create potential hazards such as leaks, which could lead to water damage or affect the operational integrity of the elevator system. Additionally, plumbing installations in these areas can complicate maintenance and emergency access.

In contrast, other locations mentioned, like mechanical rooms or garages, typically have conditions where plumbing systems can be installed, provided they meet code requirements for drainage, ventilation, and accessibility. Therefore, the restriction in elevator shafts and equipment rooms is specific to ensuring the safety and reliability of essential mechanical systems.