NABERS is a standardized building rating system which looks at the sustainability performance of commercial buildings around Australia. The National Australian Built Environment Ratings System, more commonly referred to as NABERS for short, provides a star rating out of 6, similar to an energy efficiency rating commonly seen on appliances, for buildings such as offices, hospitals, shopping centers and hotels.
One star on the NABERS scale is the lowest rating, with 6 stars the highest (a sign of a “market-leading” building, showing exceptional environmental efficiency). A building with a NABERS rating of 6 stars is exponentially better than one with 5 stars and will have almost half the amount of greenhouse gas emissions. Three stars reflects an “average” rating, but it represents a good base level, so building owners and managers can work towards energy efficiency improvements.
NABERS rating requirements looks at four categories when assessing a building’s rating:
Energy: measures energy efficiency, for example reviewing lights, lifts and air-conditioning usage
Water: measures water used and recycled
Waste: measures waste produced and recycled and looks at supply chain management
Indoor Environment Quality (IEQ): looks at the comfort of people within a building, measuring air quality, lighting, temperature and acoustics.
The rating system uses a comparison system to similar buildings and only looks at elements that a building owner/manager can influence and improve. For example, how efficiently a building separates their waste to be recycled. This means that a six-star rating is theoretically achievable for every building.
The NABERS ratings system analyzes performance over a 12-month period to reflect a range of operating situations (for example, during both summer and winter months when energy usage tends to fluctuate). It demonstrates operational performance and building sustainability across the whole year and distills it into a simple star rating.
Is NABERS mandatory?
NABERS is managed nationally by the NSW Office of Environment and Heritage, on behalf of Commonwealth, State and Territory governments and has been the system expanded internationally to the United Kingdom (NABERS UK) and New Zealand (NABERS NZ), where it is run locally with the support of the NSW Government.
While generally participation in NABERS ratings is voluntary, there are instances where it is required. For example, the Australian Government has specified that new government buildings must achieve a 4.5-star NABERS energy rating. It is also required when leasing, subleasing or selling commercial office spaces over 2,000 m². Increasingly, local governments across Australia are also requesting NABERS minimums for new large-scale developments.
Why is NABERS important?
Every building, regardless of its physical footprint, has an impact on the environment. Greenhouse gas emissions, waste disposal and water usage all contribute to the environmental impact left behind by buildings, with nearly 40 percent of global CO2 emissions coming from the built environment. Tracking NABERS ratings not only influences developers to design new buildings with sustainability in mind, it also encourages the upgrade of facilities and assets into more energy efficient ones.
Improvements to a NABERS rating are the responsibility of not just the building owner but all tenants too, and the rating requirements measure actual impact, not just intent. This means it reflects real performance, not merely plans.
A NABERS rating also provides the foundations for improving building and tenancy activity for better sustainability performance. Regular tracking and recording of NABERS ratings exposes weaknesses and areas for improvement. A reduced star rating in a category provides clear direction for focus areas.
While NABERS rating requirements are voluntary, an improved NABERS rating has considerable benefits, in addition to improved environmental impact. Reduced operating costs, such as energy bills, can result in substantial financial savings, and investments in efficiency improvements will generally pay for themselves very quickly. All of these factors also contribute to reputational benefits as well, as buildings which follow NABERS rating requirements are independently verified as being more sustainable for the environment and appealing for occupants.
How NABERS ratings are calculated
NABERS ratings are calculated by looking at data provided through measured and verified performance information, such as energy and water consumption. This information is adjusted to compare it with other comparable Australian buildings to produce a star rating. It takes energy consumption data and other metrics, benchmarks it, and converts it into an easily understood score. Given that consolidating utility data for reporting frameworks such as NABERS can be complex for organizations, IBM Envizi has developed a Utility Bill Analytics tool to support organizations with energy-intensive buildings so that utility bill data can be easily captured and interpreted into real-time insights.
Currently, NABERS ratings are available for offices buildings, hospitals, data centers, shopping centers, aged-care, apartment buildings and hotels. However, some measurement categories are only available for certain types of buildings. For example, the Indoor Environment Quality rating is only available for office buildings, as it is most relevant to measure IEQ for this building use, compared to a data center or hospital.
A NABERS rating is recognized Australia-wide as it is independently verified. Receiving a NABERS rating each year helps to track progress, or alternatively identify irregularities.
NABERS is also able to provide carbon-neutral certification for the built environment, for those that want to take their sustainability targets even further. The official NABERS website provides a range of calculation tools for estimating a building’s current ratings and for predicting what those ratings could be with changes and upgrades. These indicative results can help business owners and managers to identify opportunities for improvement.
How to improve a NABERS rating
Once a NABERS rating has been received, it works as a benchmark for tracking a building’s sustainability progress. The two ways to improve a rating are through operational changes and equipment upgrades.
For example, replacing halogen lights with more efficient LED globes can reduce energy usage by 75%, and as they require changing far less, they also result in reduced waste. An operational change that can improve a NABERS rating is to fully shut off lights and air conditioning when a space is unoccupied, for example in an office building on the weekend.
Energy management software such as IBM Envizi is another effective way of identifying weaknesses and opportunities for building optimization.