A motor home that is not somehow fixed in place is not an inhabited structure for the purpose of arson, as defined in Penal Code section 451, subdivision (b). By jury trial, appellant was convicted of violating section 451, subdivision (b), and, because of prior “strikes” convictions, was sentenced to 25 years to life in state prison. Under section 451, subdivision (b), a person is subject to the enhanced penalty under the arson statute if the arson is of an “inhabited structure or inhabited property.” The prosecutor elected to charge appellant only with arson of an inhabited structure, not an inhabited property. The evidence at trial showed that appellant set fire to motor homes and destroyed them but did not establish that the one occupied home was affixed to the ground and could not be moved from place to place. Thus, the prosecution did not prove that they were “structures,” as defined by statute. Although the trial court instructed on section 451, subdivision (d) (arson of property), this is not a lesser included offense to subdivision (b). Because arson of property includes everything except a structure, a person who commits arson of an inhabited structure is not also committing the crime of arson of property. Therefore, the appellate court, upon finding insufficient evidence for subdivision (b), could not reduce the conviction. Reversed with directions to dismiss.