I just wanted to highlight one form of shelter/housing that I think would go great after society collapses. In my archaeology class, I learned of pit houses, which were used by Native Americans across the American southwest. They worked well in the desert climate, because they regulated the temperature well. Sometimes when it comes to survival, we have to ask ourselves, "What did the indigenous people do?"
These would make great post-apocalypse homes for 2 reasons:
1) They regulate the temperature well. Cool in the hot summer. Warm in the winter (but for extra warmth, consider closing the top hole, or making it smaller. Personally, I would build mine with the entrance on the side of it.
2) Low visibility from the outside. If you construct these homes carefully, they can go unseen from anybody on the outside. The roof and walls are made of earth and blend in with their surroundings. In a world WROL, where people will gladly steal and kill to eat, maintaining a low profile is of utmost importance.
The only downside is, you might not be able to do this in a location that gets lots of rain and is prone to flood. One adjustment you can make is to spread a huge tarp over the whole thing and then cover that with dirt to better waterproof it.
Here's a few more ideas to get you thinking of shelter construction. I've included more pictures of pit houses, some bunkers, earthen homes, a hobbit home, and an underground plaza dwelling from Tunisia. I would much rather have my home be discreet like one of these than a nice house sitting on top of the ground for all to see.