Definitions of Burglary
Common Law Definition of Burglary
The breaking and entering the house of another at night, with intent to commit a felony therein, whether the felony be actually committed or not.
House includes a temporarily unoccupied dwelling, but not a building used only occasionally as a habitation.
Definition of Generic Burglary
A violent felony only if committed in a building or enclosed space, not in a boat or motor vehicle.
Congress apparently thought that all burglaries serious enough to be punishable by imprisonment for more than a year constituted a category of crimes that shared this potential for violence and that were likely to be committed by career criminals. There never was any proposal to limit the predicate offense to some special subclass of burglaries that might be especially dangerous, such as those where the offender is armed, or the building is occupied, or the crime occurs at night.
The 1984 definition of burglary shows that Congress, at least at that time, had in mind a modern "generic" view of burglary, roughly corresponding to the definitions of burglary in a majority of the States' criminal codes. In adopting this definition, Congress both prevented offenders from invoking the arcane technicalities of the common-law definition of burglary to evade the sentence-enhancement provision, and protected offenders from the unfairness of having enhancement depend upon the label employed by the State of conviction.