• The buildings we live and work in have an impact on our environment:
• We use energy for lighting, heating, cooling and ventilation
• We use water for washing, drinking, toilets and air conditioning
• Waste is generated by building occupants
• Building occupants are affected by the quality of the air
• Local biodiversity is affected by the construction and tenancy of buildings
• Natural storm water flows are redirected and often concentrated
• Toxic materials may be present in buildings
• People travel to and from buildings, often in greenhouse gas-emitting vehicles

Building owners, managers or occupants can manage and reduce these environmental impacts. NABERS is designed to provide you with a simple indication of how well you are managing these environmental impacts compared with your peers and neighbours.

The vast majority environmental impacts from buildings are due to the operation of existing buildings in the marketplace. Most existing rating systems in Australia and overseas are intended for use at the design and development phase. Whilst design is clearly of crucial importance, good design is no guarantee of sound environmental performance during operation.
It makes sense therefore to use a rating system that is specifically tailored for existing buildings, and that measures relevant impacts during the operational phase of buildings. This approach has a number of benefits, including:

• NABERS provides a rating of the things that a building owner/operator can reasonably assume responsibility for, rather than items that were decided possibly by another party many years ago and cannot be easily changed
• As NABERS is based on actual measured performance rather than on prescriptive design parameters, it is complementary to expert design tools and design-based ratings systemsNABERS is structured to recognise:
• The different realms of accountability and responsibility for commercial building owners, commercial tenants, or home owners

A building needs to have twelve months continuous energy data in order to obtain a performance-based NABERS energy rating.  However, new buildings can sign up to a NABERS Commitment Agreement and voluntarily disclose their targeted rating, modelled in accordance with certain protocols. As soon as two years have passed since the certificate of occupancy has been issued, the NABERS Commitment Agreement ends.

A NABERS energy rating rates either a base building rating or the whole building.

A base building rating covers the performance of the building’s central services and common areas, which are usually managed by the building owner.

A whole building rating also covers the tenanted space. These ratings are only disclosed when there is inadequate metering to obtain a base building rating.

A NABERS energy rating assesses a building’s energy efficiency on a scale of 0 to 5 stars. A 5-star rating demonstrates market leading performance, while a 0-star rating means the building is performing well below average and has considerable scope for improvement.

NABERS rates a building on the basis of its measured operational impacts in categories such as energy, water, waste and indoor environment. A NABERS energy rating also provides information about the greenhouse gas emissions resulting from the operation of the building.

• Energy use and greenhouse emissions – Energy-related greenhouse gas emissions are a key factor in increasing the levels of carbon dioxide in the atmosphere, leading to human induced climate change. How buildings are operated can affect their energy demand significantly
• Water use – Building users can be major water consumers, but users can also adopt practices to harvest water sustainably and effect considerable reductions in demand on existing constrained supplies
• Waste – Waste contributes to resource depletion and a range of pollutants and emissions. The reduction of waste minimises the area needed for landfill, and reduces the environmental impact of overall materials throughput
• Indoor environment – As well as minimising impacts to the wider environment, it is important for the health, satisfaction and productivity of occupants that buildings provide a comfortable indoor environment for those who use them

NABERS provides separate ratings for:

• Office buildings – This covers the environmental impacts of the activities and services traditionally supplied by, or within the control of, the landlords/operators of Office buildings. NABERS for offices incorporates NABERS Energy, NABERS Water, NABERS Waste and NABERS Indoor Environment
• Office tenancy – This covers the environmental impacts of the activities that are under the control of office occupants
• Hotels – Available for AAA-rated business hotels
• Shopping centres – For shopping centres over 15,000 sqm GLAR
• Homes – CarbonetiX does not do residential ratings

Obtaining a building’s first NABERS Energy rating can take some time, so you are encouraged to plan ahead. It will save you time and money if you compile all of the materials your assessor needs beforehand.There is new legislation as part of the Commercial Building Disclosure (CBD) Program that from 1 November 2010, office owners, lettors or sub-lettors must get a NABERS Rating when selling, leasing or sub-leasing office spaces over 2,000 m2. From 1 November 2011, full Building Energy Efficiency Certificates (BEECs) are to be disclosed.

A BEEC comprises:

• An energy efficiency rating (using the NABERS energy efficiency rating methodology)
• Information about the energy efficiency of the office lighting, and
• Generic guidance on how the energy efficiency of the building may be improved

NABERS can be used to define and set operational performance targets and measure and rate actual performance. Accredited ratings can also be used to disclose and report on performance to interested parties, establish commercial relationships for the monitoring and maintenance of performance targets, enlist professional services to improve a rating, and make decisions about priority actions or investment options.
Government agencies and councils, planning and housing authorities, and utilities may also be interested in the information that NABERS generates as a means of encouraging environmental improvement and providing incentives.