Shifting from net-zero to net-positive energy buildings

Numerous building projects have been presented as having net-zero energy performance. Such claims use a variety of different approaches: on- and off-site renewable energy technologies, purchasing green energy credits, etc. Efforts have subsequently been directed at formulating clear definitions of net-zero that provide some degree of clarity and theoretical framing. The emerging notion of net-positive energy buildings raises new theoretical and practical issues and introduces several new design considerations and possibilities. Net-positive energy is explored though viewing the role of a building for adding value to its context and systems in which it is part. Rather than considering only the generation of more exported energy versus its importation to individual buildings or the grid, the emphasis shifts to the maximization of energy performance in a system-based approach. Net-positive energy approaches open a host of new technical, behavioural, policy, and regulatory issues and opportunities not currently evident with net-zero energy buildings. These challenge the primacy of individual buildings as the most effective unit to make significant energy gains and the current prevalent expectation that each and every new building should be required to attain net-zero performance. More generally, it highlights the importance of extending the systems limits of energy analysis.