There are at least eight ratings schemes available for home owners, designers, builders and developers to use to determine how ‘green’ their building or site is, but they all have one objective.
The one thing in common across all of these rating schemes is that they strive to provide a consistent and transparent mechanism to determine how sustainable a building is, and provide consumers and the market with confidence that the buildings are genuinely reducing emissions and environmental impacts, compared with business as usual.
They vary in how they are used and what sort of developments they are relevant for, and it is no doubt quite confusing for the end users.
The key differences between the ratings are whether they focus on commercial or other types of developments, whether they cover design of actual performance, and what sort of environmental issues are covered (energy, water, waste and so on). And the cost of certification varies too.
The eight listed here don’t include the ratings of individual appliances (fridges, televisions, toilets and so on), which are different rating schemes again.
Here is a brief outline of the eight ratings schemes:
Green Star is a building environmental rating system based achieving points across nine categories, resulting in a star rating of that building, and managed by the Green Building Council of Australia. Green Star is well known in Australia and widely used.
Accredited Green Star ratings are only available for ratings at or above 4 stars. The top range ratings from 4 to 6 star are categorised as follows:
- 4 Star Green Star (45 points) – Best Practice
- 5 Star Green Star (60 points) – Australian Excellence
- 6 Star Green Star (75 points) – World Leader
There are four rating tools GreenStar Communities, Design and As Built, Interiors and Performance.
LEED (Leadership in Energy and Environmental Design) is a US Green Building Rating System based on a consensus developed standard intended for developing high-performance, sustainable buildings. The available assessment types include:
- Building Design and Construction
- Interior Design and Construction
- Building Operations and Maintenance
- Neighbourhood Development
The levels are Certified, Silver, Gold and Platinum.
LEED provides a framework for assessing building performance and meeting sustainability goals, emphasizing strategies for sustainable site development, water savings, energy efficiency, materials selection and indoor environmental quality.
The system is considered mature in the market place and is globally recognised. Over 150 countries now use a version of LEED. There are 38 registered and 18 certified in Australia.
WELL is an international performance-based system for measuring and certifying building features that impact human health and well-being.
It is similar to Green Star Interiors tool and NABERS Indoor Environment. The standard has seven factors: air, water, nourishment, light, fitness, comfort and mind.
A project is certified by a WELL assessor assigned by the Green Building Certification Institute, which administers the scheme. A WELL rating expires after three years.
BREEAM is the British Research Establishment’s (BRE) Environmental Assessment Method. It is the world’s longest established and most widely used environmental assessment method for buildings. With over 425,000 ratings and 1.9 million registered projects across 60 plus countries.
Projects can be classified under the following schemes within the UK:
- New construction
- Code for Sustainable Homes
For international projects, there are schemes for:
- New construction
- Refurbishment and fit-out
- Communities bespoke
Assessments are undertaken by a licensed assessor and are certified by the BRE.
Originally from Germany and designed for cooler climates, PassivHaus is an international building standard that is focused on energy efficiency, comfort and affordability. Recent adaptations have seen PassivHaus used in warmer climates with a number of successful projects in Australia. The standard encourages the design of low energy buildings that require little energy for space heating and cooling.
PassivHaus is based on five main basic principles:
- Thermal insulation (high performance)
- Windows (well insulated with low-e coatings)
- Ventilation and Heat recovery, (using heat recovery equipment)
- Absence of thermal bridges
Certification requirements include limits on space heating/cooling energy demand, primary energy demand, air tightness and thermal comfort.
NABERS provides four environmental rating tools to measure the actual operational performance of existing buildings and tenancies:
- NABERS Energy
- NABERS Water
- NABERS Waste
- NABERS Indoor Environment
Ratings are from 1 Star to 6 Star in ½ Star increments. NABERS can be used to rate commercial offices, shopping centres, hotels and homes.
NABERS is managed nationally by the NSW Office of Environment and Heritage, on behalf of Commonwealth, state and territory governments.
A formal NABERS rating can only be completed once the building has been operational for at least 12 months. Usually, several months are required to fully commission all systems and ensure the building is operating as intended. High vacancy rates can also dramatically reduce the rating so it is best to wait until the building is at least 75 per cent occupied.
The Nationwide House Energy Rating Scheme (NatHERS) is a star rating system for residential homes, to provide homes with a star rating out of 10 based on an estimate of a home’s potential (heating and cooling) energy use.
It is a tool for energy efficiency only, and administered by the Commonwealth Department of Environment and Energy.
One Planet Living
One Planet Living is another framework (originally from the UK, but now international), and similar to WELL, in that it is a framework that includes more than the biophysical elements of a building. Essentially it is a framework to help developments and regions to living within our means, and not proportionally use more resources than our ‘one planet’ has. The 10 key principles are:
- Health and happiness
- Equity and local economy
- Culture and community
- Land use and wildlife
- Sustainable water
- Local and sustainable food
- Sustainable materials
- Sustainable transport
- Zero waste
- Zero carbon