How is Zakat calculated for a jointly owned plot of land, the construction cost of which was estimated at three times its price, and the construction will be financed by installments from buyers, with apartments being sold in stages before the completion of construction?

Zakat is due on business assets every time a year (hawl) passes. The hawl for business assets is the hawl of the money used to purchase the land. The hawl for each partner begins from the time they acquire ownership of the money. When the hawl is completed, the land and what has been built upon it must be appraised, in addition to the cash and expected debts. Then, the total sum is divided among the partners, and zakat is disbursed at a rate of 2.5% from each partner's share. This process continues annually until the sale is complete and the installments are received.