The authors acknowledge some limitations to this methodology as discussed in the selection of primary energy as an indicator, the energy use calculation methodology and the boundaries and simplifications of embodied energy calculations. It is understood by the authors that the concept of LC-ZEB does not take into account aspects of the decision and policy-making processes such as the integration of other environmental and socio-economic aspects of building construction. However, the accuracy and applicability of proposed methodology can only improve as more detailed data on life cycle of building products and systems becomes available. In the meantime the use of the LC-ZEB, even with the assumptions proposed in this paper can offer a simple life cycle perspective to building energy assessment not currently addressed in commonly used ‘net-zero energy building’ definitions.