Board Thread:Tapped Out Help/@comment-83.34.109.125-20141014174931/@comment-173.240.24.197-20141022202239

Since they changed the look of things, they put the land expansion button in the "store". Tap on the right facing arrow that's in front of the "house" on the left side. Once that opens up, you'll see the land expansion icon (plot of land with four arrows coming out from the four sides), on the bottom row, second from the left.