Calculating the maximum load capacity of a building hoist involves several factors. First, consider the hoist's mechanical design and the manufacturer's specifications, which provide the rated load capacity. This is the maximum weight the hoist is designed to handle. Next, assess the condition of the hoist, as wear and tear can reduce its capacity. Additionally, consider the strength of the supporting structure and the safety factor, which is typically a multiplier of the rated load capacity to ensure safety. For example, if the hoist is rated for 1000 kg, a safety factor of 1.5 means the actual maximum load should not exceed 667 kg (1000 kg / 1.5). Always consult with engineers and follow local regulations and standards for precise calculations.