Think of the ways, pop culture could apply to modern houses:
-they look the same across the country
-you sometimes see them done in a similar way in other countries
-they create a more uniform landscape because they are similar across great distances
-styles change over time
-more factory made with components shipped in to the region

Folk houses:
-are traditional and people do not go in and out of fashion
-they use local materials and differ when you go from one region to another
-the word authentic applies
-are more in line with the natural landscape

-You can probably think of a few more items by simply looking at the folk versus popular culture wiki and applying it to homes. These are some of the most obvious ideas to me.