Desert Village Architecture

Too often desert villages in fantasy rpg settings don't look any different from forest villages. Usually, you get a lot of individual buildings with wide avenues between them and, most likely, a wall surrounding the entire thing.
Something like this:

Courtesy Wizards of the Coast

 The above village map is fine in a European style setting. Individual buildings that are clearly defined. However, a lot of desert dwelling peoples built their villages like this:

Al Ula, Saudi Arabia

It looks like a jumbled mess. Buildings right next to each other, or on top of each other. In many instances, the outside wall is made of the windowless sides of the buildings themselves. Why they built this way may apply to villages on Athas.

Why would desert dwelling people build confusing villages and share walls? Two main reasons, first there was no grand overall plan, and second, it used less resources.
The way a village might get started is a couple of families build homes next to each to conserve resources. Then, as other settlers arrive, or children move out, they build onto the preexisting buildings for protection and to conserve resources. Soon, you'll have a jumbled mess of houses built right next to each other. The only way around them would be to travel across rooftops.
I imagine pit-houses would also be a popular way to keep a house cooler under the blazing sun, but would be less defensible and sandstorms could bury the house easier than an above ground dwelling. However, it is possible that villages would have a communal pit-house in which they could store food, like erdlu eggs, to prevent them from spoiling as quickly as they might under the hot Athasian sun.

Athasian considerations would include protection from the sun, water, food, and protection from creatures, including man.
Protection from the sun is fairly easy, keep a roof over your head and stay in the shade. I imagine awnings would be a popular addition to any building or courtyard. Thick earthen walls would keep the heat out during the day and release it slowly during the night. However, these thermal mass walls would require more resources to build.
A village would require a spring, well, or underground cistern to gather enough water to keep the populace alive. In order to protect it from sand storms, a well or spring would be kept indoors, or at least under a cover of some kind. The entrance to a cistern would be closed off or hidden to protect it from creatures of all kinds. Water would probably be regarded as the villages most important resource.
Food could be gathered to an extent, or traded for if near a road, but most likely the village would either need to hunt or herd. There are quite a few herd animals in the Tablelands, including the erdlu, erdland, kank, crodlu, carru, aprig, etc. Because so many herd animals exist on Athas, this must be a popular way to obtaining food. Herd animals can often eat plants that more intelligent races cannot. The variety of herd animals indicate that terrain and area make a big difference in the type of animal raised. Keeping the animals protected would be of utmost importance. Hunting, would be very dangerous on Athas, as monsters are fairly common.
Protection from creatures usually come in the form of walls. Walls take up resources, so most likely the thermal mass required to keep a home comfortable would also be used to defend it. Walls facing the exterior of the village would likely be built as thick as possible with no windows. If the building is tall enough, windows might be constructed on a third floor. I imagine these windows would be only large enough to allow a magic user or psionicist to peek out during an attack.

Villages built in a roughly circular shape, with a courtyard in the middle, could serve these functions quite well. All of the buildings would need to share walls. The exterior facing walls would be built thick to protect against the sun and attack. The well, spring, or cistern entrance would be on the inside of the walls. The animals could be kept in the courtyard at night for their protection and foraged during the day.
Of course this style of village would require quite a bit of resources to build and would require planning and foresight. A large group could design and build such a village, especially if they have an intelligent ruling body. Small groups or unskilled people would have greater difficultly building a planned village of this type.

I hope this extremely brief post helps you think about the different layouts Athasian villages might take.