Her house is made of clouds, those are everywhere. All pegasi are shown to be able to move clouds. Rainbow Dash lives in the equivalent of a minecraft dirt house
Okay, and
a.) Have you SEEN some of those Minecraft homes? Even the ones made of dirt?
b.) She has her own rainbow waterfall. That shit aint cheap, and the only place most ponies can get it from are harvesting the color directly from already planted rainbows.
