The Chinese word "楼顶" is formed by directly combining the character for "building" (楼) with the character for "top" (顶), creating a compound that conceptually denotes the highest part of a structure. This process involves merging two independent meaningful elements into a single unit, where the first element identifies the object and the second specifies a particular aspect or position, resulting in a clear, intuitive representation of "rooftop" or "building top" through semantic layering.