What type of alteration is the addition of a car top emergency exit?

The addition of a car top emergency exit is classified as a minor alteration Type B. This classification is used for alterations that do not fundamentally change the nature or operating parameters of an existing elevating device but do enhance safety features or accessibility.

The inclusion of a car top emergency exit improves the safety of the elevator, providing an escape option in emergencies, without changing the elevator's operating capacity or performance. Type B modifications often involve safety enhancements that comply with regulations, which are less substantial than major alterations, thus they require less extensive review and approval processes.

While major alterations could include significant changes to the structural integrity or design of the elevator, or modifications that affect its capacity or performance, the addition of an emergency exit is considered to be a straightforward enhancement aimed at improving user safety. This distinction is essential in understanding regulatory compliance and maintenance requirements.