What should I be aiming for?Print

​​​​​If you’re starting a new project, the first step is to set energy objectives for your home. ​

Setting energy objectives starts with thinking about your current and future needs. What may seem unimportant today might be essential in the future as households change over time. For example, the energy needs of a working couple with young children change significantly as the children grow up and leave home and the couple enter retirement.


Always remember that your objectives should be driven by your priorities, not by available technologies – a 4KW PV system is not an objective, for example. Thinking only about technologies will limit the scope of what you can achieve and is likely to result in a range of isolated solutions instead of a comprehensive and integrated approach. It is also important to remember that an energy objective doesn’t exist in isolation. For example, the outcomes you seek around comfort in your home will influence your energy needs for heating and cooling (see ‘Comfort and Health​’for more information).

When setting energy objectives you need to reflect on what your priorities are. The type and scope of impact you want your home to have will influence your objectives. For example:
  • Aiming to be a certain percentage below the average energy consumption for Auckland could lead to improving the efficiency of lights and appliances.
  • A desire to keep energy costs stable over time may lead to an objective that involves some self-generation of energy.
  • If you're focused on eliminating fossil fuel use and reducing overall impact on the environment, you may consider pursuing the objective of net zero energy.
Targets, or quantified objectives, will be helpful when communicating what you want to others, such as designers and suppliers of systems. It can guide the design process and inform decision making thro​​ughout your project, and when your home nears completion it can help with testing and verification. Targets might look like one of the following examples:​
  • I want to spend $1,500 on my energy bill per annum.
  • I want my energy budget to be no more than 8% of my income. 
  • I want to use no more than 800 kWh per month during winter. 
  • I want to achieve net zero energy.
Once you’ve set your energy objectives you should include them in your design brief. Establishing objectives before finding a designer will help you to measure their response to them and assist in finding the right team for your project. Your energy objectives, along with objectives in other areas, will help guide the design process and will need to be taken into account throughout the design stages. 

An alternative to setting your own energy objectives and targets is to use one incorporated in a building rating tool. Building rating tools and certification systems help homeowners set and quantify their objectives by providing benchmarks and strategies that have been tested and implemented by others. 

The table below explains how energy criteria are addressed in each of the tools discussed in these articles, and lists the objectives and benchmarks they have set.

Certification scheme

How does it address energy objectives?

Energy targets

Building Code

Focuses on the bare minimums to ensure occupants’ health.

Addresses energy efficiency in clause H1.

Dictates minimum R-values to be used and glazing percentages to reduce heat loss.

Performance targets are not set for residential buildings within the Building Code.

Living Building Challenge

Aims to create a future in which the built environment relies solely on renewable energy sources.

Buildings need to achieve net zero energy without the use of on-site combustion, in addition to meeting all the other requirements of the standard.

On an annual basis, the building has to produce 105% of its energy needs from renewable energy sources.

Net Zero Energy

Focuses on one objective: achieving zero energy, which means that the amount of energy consumed by the building will be less than – or equal to – the amount of energy generated on site.

Forbids the use of on-site combustion, which means a home seeking this certification cannot use gas.

On an annual basis, the building has to produce 105% of its energy needs from renewable energy sources.


Addresses energy objectives in terms of reduced energy use and occupants’ thermal comfort.

The ‘Energy, Health and Comfort’ category accounts for almost half of the points in the Homestar tool.

Focuses on improvements of the thermal envelope and on the selection of efficient systems and appliances to minimise energy consumption and CO2 emissions.

In the Homestar Technical Manual v.3​, a summary table is provided to illustrate the various energy benchmarks (kWh/annum/m²) that have to be achieved in order to be awarded a certain number of points.


Passive House

Certified Passive Houses offer comfortable and healthy indoor environments with minimal energy consumption. Limits on heating and cooling energy, as well as primary energy, and a stringent quality assurance process safeguard the performance of the building fabric and fresh air system. Post-occupancy evaluation of Certified Passive Houses regularly confirms that these objectives are achieved in practice.

Consumption maximum of 15kWh per square meter a year for heating and cooling. A cap on all sources of primary energy used in the home of 120 kWh per square meter a year.


High Standard of Sustainability (HSS)

Sets an energy benchmark for existing and new homes. This target is a starting point based on best available national information and it is expected to be revised over time.

New homes in Auckland6 should use no more than 5,800kWh of reticulated energy per year while existing houses should aim for no more than 6,200kWh of reticulated energy per year, regardless of their size.

6The HSS tool segments New Zealand into ‘Climate Zones’. Auckland is in Climate Zone 1.​
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