Final answer:
The building code typically requires a ladder, staircase, or platform as access to a water heater installed on a roof over 15 feet high, unless the Authority Having Jurisdiction approves alternative means to ensure safety.
Step-by-step explanation:
The question relates to building code requirements for safely accessing equipment installed at heights. When a water heater is installed on the roof of a building which exceeds 15 feet in height, the code generally requires safe and reliable means of access. The direct answer to the student's question is not provided without the specific code being referenced. However, common code requirements generally specify the necessity for an access point such as a ladder, a staircase, or a platform to reach the water heater, unless alternate means have been approved by the Authority Having Jurisdiction (AHJ). The AHJ has the authority to accept alternative solutions that provide equivalent safe access. These building codes are intended to ensure the safety of service personnel who may need to repair, maintain, or inspect the water heater. This is in line with the building codes of many More Developed Countries (MDCs), which enforce safety features such as running water, working ventilation and heating systems, stable construction, smoke detectors, and properly installed electrical wiring.