Why don't we build houses out of adobe?

Adobe is rare in modern US homebuilding for three reasons: labor expense, seismic restrictions, and crew training. Material cost is low — site-formed bricks run $2.50–$3.00 each — but skilled adobe labor consumes half a contractor's budget per Architectural Digest. California effectively banned new unreinforced adobe for decades after seismic-code revisions. Codes elsewhere demand reinforced bond beams, steel rebar, and engineered footings that erase the material savings. Adobe also performs poorly in wet climates because rain erodes unplastered walls. Where labor is local and climate is dry — New Mexico, Arizona — adobe continues to be built routinely under standard residential permits.