Arson was defined at common law as the malicious burning of the
dwelling of another, while house burning was burning your own house and
endangering the property of others. In most states, arson has been
extended to include burning structures besides dwellings, burning your
own property for illegal purposes, and damage caused by a fire or an
explosion. Now if someone burns his/her home to collect the insurance,
since the insurance is higher than the depressed real estate value,
that would be arson. Other examples of arson would be to burn or bomb a
place of worship in a hate crime, or burn a building in revenge for a
refusal to sell it.
If a person burns down his own home as a form of cheap demolition and
accidentally sets half the neighborhood on fire, that may or may not be
arson, depending on the laws of the state.