Revelation 21:1,2 (KJV)
1 And I saw a new heaven and a new earth: for the first heaven and the first earth were passed away; and there was no more sea.
2 And I John saw the holy city, new Jerusalem, coming down from God out of heaven, prepared as a bride adorned for her husband.
New Jerusalem Will Come Down, Not Built
Mormons claim that they will build the New Jerusalem. This was taught by Joseph Smith, unfortunately it is a false teaching. The Book of Revelation is clear that New Jerusalem will come down from heaven.