The plot will then be marked on your map. After receiving permission, you may purchase the land from the relevant steward for 5,000 gold. In Morthal, you will need to see the steward about obtaining permission in Falkreath and Dawnstar, it is the jarl who grants permission. Once you've obtained the favor of the Jarl of Falkreath Hold, Hjaalmarch, or the Pale, usually by doing quests for them, you will be given the right to purchase a piece of land in the hold.