Modelling the through-life costs and benefits of detached zero (net) energy housing in Melbourne, Australia

• Three housing performance scenarios were analysed, including a zero energy scenario.
• Zero energy house calculated to have the lowest accumulated costs across time.
• Improved housing environmental sustainability aids housing affordability.
• Renewable energy is important for achieving low housing operational costs.

Zero (or low) energy housing standards are being implemented in several developed countries and represent international best practice for minimum performance outcomes for new dwellings. However, the debate in Australia regarding housing energy performance continues to revolve around ‘sustainability’ versus ‘affordability’, with affordability typically prioritised as the more pressing short-term policy challenge. There is limited analysis informing this debate, particularly regarding higher energy efficiency requirements and the integration of renewable energy technologies to achieve a zero (net) energy house (ZEH) outcome. This paper aims to address the limited empirical evidence regarding costs and benefits of ZEH in Australia. A cost–benefit analysis focusing on new detached housing in Victoria, Australia was undertaken to determine upfront and through-life costs and benefits of ZEH performance. Results show that ZEH is a least cost scenario, in terms of capital and through-life operational energy costs, compared to a business as usual approach or improving the thermal performance of the building envelope only. The research highlights that ZEH standards are economical in Australia and that sustainability assists with affordability when a through-life perspective is applied.