You start the game with 3 instead of 2 Dwellings. Place the third one after all players have placed their second ones (but before the Chaos Magicians have placed their only Dwelling).
After building the Stronghold, take an Action token. As a Special action (once per Action phase), you may transform a Terrain space directly adjacent to one of your Structures into your Home terrain (Sandstorm). On this space, you may immediately build a Dwelling by paying its costs. (This ability is not applicable past a River space or Bridge.) Use the Action token to keep track of using this Special action. (The Sandstorm is not considered a Spade.)
The Nomads' faction board
Nomads are a horse people of the desert. They used to be living in tents and always on the move. Even today, they build their dwellings using plain and light materials. This way they can populate large areas really quickly. Nomads only dwell in deserts, and their hordes of horsemen can cause a sand storm that may propagate to neighboring landscapes.
By Kay-Viktor Stegemann