An Overview of Net Zero Homes

About this course.

A net zero home is one that, measured over a typical year, balances what it takes from the energy or carbon "ledger" against what it gives back, so the net figure is zero. In practice this is achieved by first making the home need very little energy, then meeting that need efficiently, and finally generating clean energy on site (or accounting for remaining emissions) so that the annual balance nets out. The crucial distinction is between net zero energy, which balances energy in kilowatt-hours, and net zero carbon, which balances greenhouse gas emissions — two related but different targets that can lead to different design choices.

Net zero energy means the home produces at least as much energy over a year as it consumes, typically by generating renewable energy on site — most commonly rooftop solar — equal to or greater than the energy it draws in. Because a home uses grid electricity at some times (such as evenings and cloudy days) and exports surplus solar at others, "net zero energy" is an annual balance rather than a moment-by-moment one: the home may import and export throughout the year, but the totals cancel out. This is a useful, measurable and widely understood definition, and yourhome.gov.au discusses homes designed to reach it.