What is NABERS Rating and why do we have it?
The National Australian Built Environment Rating System (NABERS) is an initiative by the Federal government to measure the environmental quality of building developments. The ratings ranging from 1 to 6 stars, measures greenhouse gas emissions, energy, waste, water efficiency and indoor environment quality of existing buildings in several categories.
The formulation of NABERS grew out of the need to create sustainability in commercial spaces and buildings. Buildings use 40% of the world’s energy resources, emit 40% of the world’s carbon footprint and use 20% of the world’s available drinking water. As we gain further scientific knowledge about the impact of such behaviours, it is has become necessary for the government to take action in restoring the notion of sustainable usage. To ensure greater efficiency in usage, it is necessary to measure and understand the environmental performance of a building. This is done through a NABERS rating, which provides an indication of how well environmental impacts of a building are being managed in comparison to similar buildings.
The ratings are used by property managers, building owners and tenants to improve the environmental performance of their buildings and workplaces. This rating system was introduced in 1998 in NSW as the Australian Building Greenhouse Rating (ABGR), by the NSW Sustainable Energy Development Authority (SEDA). By 2000, the property industry had pushed for the ABGR tool to become nationally standardised. Furthermore, it was agreed that the ratings tool should be based upon the performance of the buildings in each locality. During this national standardisation process, NSW and Victoria were the first states to have sufficient local information to establish the necessary benchmarks.
The NSW government was awarded a tender to commercialise NABERS in 2005. Once standardisation was complete nation-wide, in 2010 the Commercial Building Disclosure Scheme used NABERS as a means of disclosing building energy efficiency at the point of sale or lease. By 2013, the NABERS system became an internationally recognised program, with NABERS NZ, being launched in New Zealand.
How does the NABERS rating system work?
Using 12 months of measured performance indicators, such as energy and water bills, NABERS provides a star rating ranging from 1 to 6 that represents its current operational performance status.
The ratings take into consideration the following factors before delivering a complete status :
- The climate conditions under which the building operates
- The hours of building and office space use
- The level of service that the building provides to its occupants
- The energy source it uses to conduct these services
- The size and occupancy of the building itself
The ratings are obtained from a benchmark projection that represent the optimal use of buildings and performance levels of other buildings in a similar style, usage and location. For example, a 6 star rating demonstrates market-leading performance, while a 1-star rating means that the building has considerable scope for improvement. These ratings are valid for 12 months, because an annual review ensures that the rating accurately represents the building’s current operational performance at any given point in time.
The NABERS program has the ability to convert detailed technical information about a building’s environmental impacts into an easily understood star rating that demonstrates how a building or a tenancy is performing in comparison to similar buildings in its location.
Building owners and managers, further use NABERS ratings to set targets for building or portfolio upgrade projects. The NABERS Energy and Water tools for offices, shopping centres and hotels measure performance on a rating scale from 0 to 6 stars, as does the NABERS Indoor Environment for offices tool. The NABERS Waste for offices tool, measures performance on a rating scale from 0 to 5 stars.
The NABERS Rating Scale:
NABERS Indoor Environment, Energy and Water tools for offices, shopping centres and hotels ranging from 0 to 6 Stars :
- 6 Stars - Market leading performance
- 5 Stars - Excellent performance
- 4 Stars - Good performance
- 3 Stars - Average performance
- 2 Stars - Below average performance
- 1 Stars - Poor performance
- 0 Stars - Very poor performance
NABERS Waste for offices ranging from 0 to 5 Stars :
- 5 Stars - Market leading performance
- 4 Stars - Excellent performance
- 3 Stars - Good performance
- 2.5 Stars - Average performance
- 2 Stars - Below average performance
- 1 Star - Poor performance
- 0 Stars - Very poor performance
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What is Indoor Environment?
The NABERS Indoor Environment (‘IE’) tool, first released in 2009 measures the indoor environment performance of offices and also reward those office spaces that are environmentally efficient. A NABERS rating provides an industry respected, demonstrable advantage in the market, proving sustainable and leadership credentials in the property industry.
The rating provides a commonality and acts as a link between multiple parties who are involved in the process of setting goals and evaluating occupational health standards, while achieving performance targets in a sustainable manner. The ratings allow for all related parties to further pinpoint areas for improvement and to better evaluate upgrades to services in response to the occupants’ needs.
Key indicators of an office delivering an appropriate level of comfort to its occupants is dependant on various factors such as the temperature, relative humidity, the presence of draughts or air pollutants, the cleanliness of the air, internal noise levels, sufficient yet unobtrusive lighting and how the space is ergonomically arranged. While some of these factors can be controlled by building services, others are based around management decisions. The IE tool accounts for the varying roles and responsibilities within each building management structure, and thereby provides 3 different rating types - base building, whole building and tenancy.
- Base Building → For building owners and managers who control and maintain the thermal services, air systems and cleaning
- Tenancy → For tenants who control the materials within an office space including lighting and internal noise
- Whole Building → For larger organisations who manage the building as well as occupy the internal office space. The factors associated with both tenancy and base building are factored into this rating type
The IE tool uses quantitative measurements based on the rating, and an occupant satisfaction survey and assess the quality of the office’s internal comfort conditions. Similar to all the other NABERS tools, it is based on a 12 month rating period.
To assess the comfort conditions there are 5 factors :
- Thermal services including the temperature, mean radiant temperature, humidity and air speed
- Indoor air quality including ventilation effectiveness and levels of pollutants
- Lighting to maximise daylight, while minimising glare and heat
- Acoustic comfort including the ability of the building to minimise external noise as well as the noise levels within the tenanted space
- Office layout including the spatial arrangements of walls, partitions, furniture and equipment in relation to fixed elements, like windows and heating, ventilation and air conditioning
From 1st July 2017, the Building Energy Efficiency Certificates (BEEC) has undergone changes as a result of changes to the Commercial Building Disclosure Program (CBDP). Before this change, lessors were required to provide energy efficient information when leasing or selling commercial office spaces that were 2,000 square metres or more. Now this number is set to 1,000 with the introduction of these changes. The aim of this is to promote energy efficiency objectives of commercial office buildings and to provide more information to individuals who are buying and leasing.
The NABERS Energy rating, which is valid for a year closely ties into this, as the information provided in a NABERS Certificate is necessary for a valid BEEC during sale or lease.
The higher the number if stars on a NABERS certificate the lower the greenhouse gas emissions of the building will be and therefore the building will have a smaller environmental footprint. If a NABERS rating certificate demonstrate the maximum number of stars, this means that there are lower greenhouse gas emissions for the development compared to most of the similar buildings in the same area. The rating is based on a calculation of benchmark figures, related to buildings in the same category using 12 months of consumption data. The consumption figures are then adjusted to include building area, hours of use, climate zone, equipment density and greenhouse intensity of the energy source.
The NABERS Water tool measures the water consumption of an office building on a scale of one (least efficient) to six stars (market leading/most efficient) reflecting the performance of the building in comparison to the rest of the market. The average rating within the market at this time is around two and a half stars. While the ratings are being determined, in order to productively compare performance, the figures are adjusted for factors such as building area, hours of use and climate zone. It does not take into account the consumption of internally or externally supplied recycled water or water from on-site sources such as rainwater tanks. The total amount of externally supplied recycled water is used in the rating process but does not ultimately affect the rating- rather it is used to help the building owner understand the total water consumption of the building.
The NABERS water rating tool is only available for whole buildings and not for tenancies. This can also be conducted at the same time as a NABERS energy base building, or whole building rating.