Assalaamu alaikum. My brother bought one plot of land 12 years ago with the intention of building one house for his personal use. Recently, however, he bought second plot and change his plan to built house in second plot and plan to sell first plot in order to use that money to construct the house in second plot . so is zakath payable for first plot or second plot. Already he had paid one time zakath money on first plot as per plot current valve and there is no income from the plot.

All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad is His slave and Messenger.

Your brother does not have to pay zakah for either of the two plots of land. Regarding the second plot, he did not buy it with the intention of trading with it, but he bought it to own it, so it is not a tradable item.

Also, there is no zakah on the first plot, as he bought it in order to own it and not with the intention of trading with it. The fact that he changed his intention after that and wanted to sell it does not make it a tradable item, and there is no zakah on it. Imaam An-Nawawi said, “The mere intention of trade does not make the money (wealth) subject to trade; if he wanted to possess something and he owned it by purchasing it and so forth, and then he subjected it to trade, then it is not considered as trade; this is the view of the School, and it is the view which the majority of the scholars adopted…” 

Also, Shaykh Ibn ‘Uthaymeen,  said, “If a person has a piece of land that he bought without having the intention for trade and then inclined to offer it for sale and said to himself that he would build a house at another place; is there any zakah on this land? No, because it is not for trade but he intended to sell it to get rid of it… not to make a profit out of it.”

In case he sells the land and a whole lunar year elapses with its price in his possession, then he must pay zakah on the price if it reaches the Nisaab (minimum amount liable for zakah) by itself or with other wealth that he owns, or gold, or silver, or tradable goods; so he pays zakah then, which is 2.5%. In case he spends the price on construction or other things before a whole lunar year elapses, then he does not have to pay anything.

Allaah knows best.