I would like the ruling for a plot of land which has been readied for construction and left with the purpose of its price increasing in the future. Do I need to pay zakat every year by estimating its worth?

Zakat is not due upon the mentioned plot of land as long as it has been readied for construction and has not generated any profit, except after selling and saving the proceeds and a duration of one year then passing. The amount due is one quarter of a tenth (i.e. 2.5%) of its worth. Thus, zakat is not owed on the proceeds if they are spent before the end of that year.

Allah Knows the best