To safely lower an object after using a building hoist, ensure that the area below is clear of people and obstacles. Slowly release the hoist's brake or control mechanism, allowing the object to descend gradually. Keep a steady hand on the controls to maintain a controlled descent. Monitor the object's position and communicate with ground personnel if necessary. Ensure all safety hooks and attachments are secure until the object reaches the ground. Once the object is safely on the ground, secure it and disconnect it from the hoist. Always follow the manufacturer's guidelines and safety protocols for the specific hoist being used.