About
The Household Energy End-use Project (HEEP2) is a national study to establish when and how energy is used in New Zealand homes.
HEEP2 is analysing data from a national sample of over 750 households. Data collection included combinations of self-completion and onsite surveys, in-home monitoring and accessing metered energy data from retailers.
The data from HEEP2 will provide evidence to inform how energy can be used more efficiently, to reduce bills and lower carbon emissions, while also making it easier to keep homes warm and dry.
HEEP2 builds on the success of the original HEEP study, which ran from 1995 to 2005. Comparisons between the findings of the two studies will show how energy use and home conditions have changed over the past 20 years.
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Current status
The data collection phase was completed in April/May 2025.
Analysis of the data is underway. The first two reports have already been published:
- SR495 Household Energy End-use Project 2 Report on winter comfort, heating and indoor temperatures (preliminary analysis) (2024)
- SR502 Household Energy End-use Project 2: Report on summer comfort, cooling and indoor temperatures (preliminary analysis) (March 2025)
Partner acknowledgements
BRANZ wishes to thank Stats NZ for supporting household recruitment. We are, of course, grateful to the household participants themselves, without whom the HEEP2 study would not be possible.
Funding acknowledgements
This research was funded by the Building Research Levy, with co-funding from the Ministry of Business, Innovation and Employment. New Zealand Green Building Council provided additional funding for the related Canterbury-based high-performance and code-minimum study.
More information
What is the project doing?
HEEP2 seeks to:
- collect data on energy use and conditions in New Zealand homes
- understand the purposes for which energy is used, such as for heating, cooking and entertainment
- provide insight into household energy-use behaviours and practices
- collect information on dwelling characteristics and household appliances
- provide data to support the transition to a zero-carbon built environment and reduce energy hardship in Aotearoa New Zealand.
What data is being collected?
For more details see the HEEP2 data catalogue and other information under Information for researchers.
Why is this important?
The data collected from HEEP2 is crucial for:
- developing strategies to reduce greenhouse gas emissions in both existing and new buildings
- ensuring that all New Zealanders have warm, dry, and healthy homes that are affordable to run
- informing policy makers and stakeholders about current energy use and opportunities for improvements.
How are we doing this?
- Households were recruited to take part in the national HEEP2 study through the Stats NZ Household Economic Survey. Over 750 households are taking part in some capacity.
- Data collected in HEEP2 includes a combination of self-completion and onsite surveys, in-home monitoring and accessing metered energy data from electricity retailers.
- In addition to the national sample, over 40 homes in Canterbury are being studied as part of a related project focusing on higher performance and Code-minimum homes.
Updated: 5 August 2025