Does property engineering supervision earn much extra money?

Engineering supervisors can earn thousands of dollars by doing private work.

When you calculate the decoration management, turn a blind eye, it is estimated that there are two or three thousand, but you still have to be some decoration inspectors and project managers. Parking supervisors can earn 10,000 to 20,000 yuan by deducting parking fees privately. The rest, the greening supervisor and the customer service supervisor basically have no extra money.