The different levels of Net-Zero Buildings
• Energy-efficient: a building with a high degree of energy efficiency in its fabric and building services that consume energy, e.g. heating, cooling, cooking, lighting, ventilation, hot water and appliances.
• Low-carbon: a building that is energy efficient (low energy) and is supplied by low-carbon energy. Some building services equipment may not be capable of decarbonizing without being replaced (e.g. fossil gas boilers).
• Nearly zero-carbon: a building that is energy-efficient and may have some available zero-emission energy supply (onsite or offsite), but that does not offset 100 per cent of the building’s energy demand.
• Net zero-carbon: a building that is energy efficient and relies on zero-emission energy sources that meet the energy demand over the course of a year (or another established timeline, e.g. a month).
• Zero-carbon: a building that is energy efficient and has its energy demand completely met through zero-emission energy generated either onsite or offsite.
• Carbon-negative: an energy-efficient building that generates renewable energy onsite that not only fully covers the building’s own energy demand, but also produces excess renewable energy which is fed back into a grid and can be used for other offsite purposes.
• Whole life cycle, net zero-carbon: A zero-carbon building with the additional requirement that the embodied emissions associated with the materials used for construction are themselves net zero, either through decarbonization or offsetting
