Existing Rating Tools – Residential & Commercial.
Introduction:
Below is a brief overview of the existing residential and commercial rating tools at both the National
and State levels, it does not specify which rating tool is best, rather it provides a short description of
them whilst highlighting some of their strengths and weaknesses.
NATIONAL
NatHERS – National House Energy Rating Scheme: www.nathers.com
Developed by the CSIRO, NatHERS is a House Energy Rating software application that estimates
the heating and cooling energy consumption of a house design. The software performs hourly
calculations for heating and cooling over a year, based on specific information such as dwelling
design, dimensions, construction materials, orientation and post-code climate zone for a
standardised occupant pattern.
The results allow the ranking of a dwelling in terms of performance. However, the standard
occupant pattern is not designed to predict actual or typical household energy use. NatHERS
provides a rating of between 0 and 5 stars, which shows the potential of the house to have low
energy requirements for heating and cooling.
NatHERS is not based on actual performance; it is simply based on the design of dwellings. In turn,
it fails to deliver predicted savings in actual operation.
Australian Building Greenhouse Rating Scheme: www.abgr.com.au
The Australian Building Greenhouse Rating scheme is a national program that benchmarks
commercial office buildings' greenhouse impact on a scale of one to five. The more stars a building
or tenancy receives, the better its greenhouse performance. A Three star rating represents current
best market practice.
The scheme provides a national approach to benchmarking the greenhouse performance of
buildings and tenancies. A higher star rated building is attractive to tenants and investors due to its
lower operating costs and it's enhanced greenhouse performance.
Building managers, owners and tenants can self assess the greenhouse performance of their base
building, whole building or tenancy at no cost using the Australian Building Greenhouse
Performance Rating Calculator. Using 12 months of energy consumption (from bills) and some
other details such as the number of people, number of computers, net lettable area and the hours of
occupancy, you can obtain a star rating that indicates the greenhouse performance of your office
building
NABERS- National Australian Building Energy Rating Scheme.
NABERS is a broad-brush tool that gives a rating of the overall environmental impact of a building.
NABERS is not a tool for environmentally sustainable design, although it provides performance
targets for designers to aim at. It is based on a measurable performance rather than a prescription,
thus it does not cover the use of recycled materials, construction waste and noise.
NABERS consists of a two part format: Building questions related to, for example, physical fabric
and User questions that relate to things, for example, number of people using building. It is not a
design tool as it rates the performance of buildings that are in existence or use.
NABERS uses a reporting system rather than a weighting, thus the system makes use of measured
results to provide its ratings. The advantages of this are that the results are not simulated, whilst the
use of measurements avoids the problems of prescriptiveness. Measurements minimise the need
for a body of expert assessors, while the use of measurement allows the incorporation into the
rating of buildings of all types and ages.
STATE
ActHERS – ACT House Energy Rating Scheme: www.palm.act.gov.au
Developed in 1995, the ACT House Energy Rating Scheme has been designed to be consistent
with the National House Energy Rating Scheme (NatHERS). It assists in informing householders
and the building industry in evaluating how well a new residence will perform in the efficient use of
energy for heating and cooling, by assessing its design, siting and construction.
-2Furthermore, it defines this performance in terms, which are consistent with regard to climate,
design and individual preference. This is commonly expressed as the star rating, where houses are
rated from 0 to 5 stars depending on how energy efficient they are seen to be. In essence,
ActHERS is based on NatHERS so that the ACT building industry would not be disadvantaged
nationally. A point score is allocated to each feature that applies to the house. Scores are added up,
and a corresponding star rating is given. ActHER also provides the designer or assessor with
information to further improve the house energy rating performance.
The ACT House Energy Rating Scheme considers:
 Siting [orientation of the residence; vicinity to adjacent dwellings]
 Design [aspect of windows in living areas; ceiling height]
 Construction [thermal performance of walls and floors; air leakage]
Energy Efficient Ratings (Sale of Premises) Act 1997.
Requires the disclosure of an existing dwelling’s energy rating by vendors to purchasers prior to
advertising or entering into a contract for sale.
ActHERS is based on design features to reduce energy. However, the behaviour of occupants and
the energy efficiency of major appliances are also very important in overall energy consumption, but
are not considered in ActHERS. (www.palm.act.gov.au)
New South Wales
NSW Planning – BASIX: www.planning.nsw.gov.au
Basix attempts to address all aspects of sustainable building design across residential, commercial
and industrial building types. The residential sector is receiving priority attention. It aims to set clear
benchmarks for acceptable industry practice, a framework for industry to better that practice and
allow for local and regional adaptation where required. In essence, Basix is not a single issues
approach to sustainability and development control.
BASIX is a web-based planning tool for councils and proponents of residential dwellings to assess
the potential performance of their development against an agreed set of sustainability indices.
BASIX is designed for all common residential dwelling types, which are detached dwellings, villas,
townhouses and multi-unit apartments.
The BASIX tool has two key parts, the building and context components. To date BASIX has
focused on the building component, which assesses the response of a building proposal to the
opportunities presented by the context of the site and its infrastructure. The BASIX tool encourages
developers to focus on the sustainability areas that can reasonably be addressed, such as
environmentally appropriate energy and water efficient systems and appliances, building materials
and landscaping. The second phase of BASIX focuses on the context component, which factors in
the context of the proposed development. This will include assessing integrated land-use, transport,
stormwater systems, water supply and energy infrastructure, all of which are beyond the control of
the developer.
BASIX considers a range of sustainability indices to rate development proposals and potential
performance. The nine BASIX indices are:

Site

Social

Transport

Water

Stormwater

Energy

Waste and recycling

Materials

Indoor amenity
Victoria and Western Australia
FIRSTRATE – Housing Energy Rating: www.seav.vic.gov.au
-3The FirstRate House Energy Rating Software Package provides a simple method to assess and
improve the energy efficiency of house designs and completed homes. The FirstRate computer
program rates homes using the 5 star scale, with 5 stars being the most energy efficient. FirstRate
includes two house energy-rating modes: the comprehensive FirstRate mode and the fast and
indicative QuickRate mode. QuickRate is particularly useful at the sketch design stage. The draw
back to FirstRate is that it cannot be used in hot and humid climates.
The house energy rating is independent of the size and type of housing, ensuring that both large
and small houses, attached and detached dwellings have the potential to achieve a good energy
efficiency rating..
Queensland
Building Energy Rating Scheme: www.solarlogic.com.au
BERS allows the assessor to select whether mechanical cooling is to be used and can assess a
number of natural ventilation options. The BERS (Building Energy Rating Scheme) computer
program was developed by Solar Logic. It is a tool capable of simulating and analysing the thermal
performance of Australian houses in all climates from Alpine to tropical. Unlike other HERS
programs, BERS allows the assessor to select whether mechanical cooling is to be used and can
assess the performance of a number of natural ventilation options. Its most common application is
currently in Queensland but it is equally appropriate in other states.
Some of the specific features of BERS include:
 Assigns star ratings to specific house designs according to their particular climate
type.
 User interface of the program is graphics based.
 Data entry about the building, the type and the conditions of use is selected from
pictures displayed on the screen.
 Floor plans are drawn with a mouse. This eliminates the need for time consuming
data entry of dimensions, orientations, adjacent zones etc. making data entry fast and
accurate.
 Calculated data is displayed in graphic form as well as being written to files.
 Output files can be printed, or imported into spreadsheets, (for further processing), or
moved into reports generated by word processors.
 BERS provides a comfort index (degree hours of discomfort) for buildings, which are
not heated or cooled mechanically. This is based on temperature, air speed, relative
humidity and acclimatisation. This feature allows designers and occupants to design
heating and cooling around occupation patterns.
SEDA is expanding its Australian Building Greenhouse Rating (ABGR) Scheme into the residential
market. The objective of the Residential ABGR scheme is to guide best practice beyond the
existing regulation of the Energy Smart Homes Policy and the Building Code of Australia, by
rewarding high performance homes and raising the awareness of the benefits of reducing
greenhouse gas emissions within the residential sector. In turn, it’s envisaged that the performance
rating will enable various products, services, and policies to be developed as to encourage and
reward good energy performance.
Like its commercial counterpart, the residential scheme will offer a two-tiered service: a free and
simple web-based self-assessment tool; and an accredited star rating offered through a network of
registered assessors. The potential exists to expand the role of Accredited HMB Assessors from
providing NatHERS assessments for new designs, to the whole-of-home performance ratings
required by SEDA's ABGR residential scheme.
It should be emphasised that the tool is a greenhouse performance benchmark for the residential
sector and not a design tool. Data collection will include: billed energy use; climate; home siting,
structure, appliances, products; occupant behaviour.