Thermal tempering of glass is a treatment process used to enhance safety upon the breakage of glass structures. This process results in relatively high residual compressive stresses at the outer surfaces and high tensile stresses within the interior of a glass panel, which causes the glass component to break into relatively small fragments instead of shattering into large pieces. This contribution addresses the development of an efficient eigenerosion technique to model complex fracture patterns using the finite element method. It is aimed to present an eigenerosion formulation, which is capable of modelling multiple crack initiations, crack branching and fragmentation of tempered glass in a relatively efficient manner. The main advantage of eigenerosion is the capability of modelling fracture without the need of introducing an extra degree of freedom to express crack propagation [1,2]. The realistic modelling of the crack driving energy is considered, where several associated decompositions are discussed and implemented within the suggested computational framework. Several numerical aspects including mesh dependency and the computational efficiency of the eigenerosion approach are addressed, where associated numerical solutions are proposed. The suggested numerical formulation is employed to simulate the complex fracture behaviour and fragmentation of tempered glass.