Is Zakat obligatory on a piece of land that was purchased with the intention of investment, then the owner's intention changed after a year and a half to private construction, knowing that construction will begin three years after the date of purchase, and that the owner follows the Shafi'i school of thought?

If the land was purchased with the intention of trading, its zakat (definition) is obligatory for the years in which the intention was for trade, at a rate of 2.5% of its value if it reaches the nisab (definition). However, once the intention changes from trading to ownership, the land becomes an asset held for personal use (ard qinya), and no zakat is due on it. Zakat ceases from the moment the intention changes, because the intention of ownership is sufficient to waive zakat on trade goods.