What are the elements of a burglary?

The elements of burglary are: Entry into a building with the intent to commit a felony or theft. ( Pen.Code, 459.) Entry occurs when part of a person's body or an instrument, like a rock, penetrates the outer boundary of a building. (See Magness v. Superior Court (2012) 54 Cal.4th 270, 273, 142 Cal.Rptr.3d 268, 278 P.3d 259.) " [T]he roof, walls, doors, and windows constitute parts of a building's outer boundary, the penetration of which is sufficient for entry. [Citation.]" ( Id. at p. 274, 142 Cal.Rptr.3d 268, 278 P.3d 259.)