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Progressing energy performance certificates for homes

The introduction of home energy performance certificates (EPCs) has the potential to improve housing conditions, reduce home energy costs and cut carbon emissions. New BRANZ research provides valuable insight into the style of EPC that could best fit the Aotearoa New Zealand context.

Published August 2023

The carbon emissions from the day-to-day energy use of Kiwi homes are responsible for approximately 60% of a residential building’s carbon footprint. Residential operational energy results from energy used for heating, lighting and cooking in the home.

By focusing consumer attention on home energy performance – in the way EECA energy ratings do for appliances – home EPCs have the potential to drive positive behaviour change among consumers and the industry.

In Australia, Europe and parts of North America, EPC schemes give people information on how energy is consumed in their homes. By understanding how any given home performs against universally accepted metrics and benchmarks, consumers can make informed purchasing, rental and home renovation decisions.

In New Zealand, energy performance ratings are commonplace for commercial buildings and are often a key consideration in the design of new-build homes. The government is proposing to make energy performance ratings mandatory for new and existing public, industrial and large-scale residential buildings.

This BRANZ research, which started in 2019, is providing valuable evidence on the challenges and success factors of methodologies used in Australia and the UK. It offers insights into how Kiwis perceive EPCs and their potential benefits and how a certification scheme could be introduced for maximum uptake and success.

The potential impacts of home EPCs for New Zealanders are widespread – from educating and influencing purchasing decisions to long-term policy making. For consumers, EPCs will help with estimating annual energy bills and assessing whether a prospective property would make a warm, dry and healthy home.

At a national level, aggregated data from EPCs would help capture the energy performance of the country’s housing stock to inform future policy making. An EPC scheme would make it possible to identify the worst-performing homes where improvements could be targeted to make the biggest positive difference to living conditions, and overall carbon emissions.

This evidence suggests that home EPCs could be a practical tool to reduce emissions and move towards reaching climate change goals.