How is the zakat calculated for land on which construction has begun for investment, knowing that the construction period may take four years?

Real estate investment zakat (definition) depends on the investor's intention. If the intention is to rent, then zakat is due on the rent if it reaches the nisab (definition) and a full year has passed over it, not on the property itself. However, if the intention is to sell after construction, then zakat is due on the value of the land and buildings each year at a rate of 2.5%, even if the buildings are not yet complete, because they are considered trade goods.