Sustainability Assessment tools – comparison
The type of building to be assessed determines the potential tools available for assessing that building. It is not always practical or possible to achieve an assessable 5 or 6 star rating for some buildings. The most common rating tools can be reviewed briefly as follows:
1. Residential energy ratings – NatHERS (Nationwide House Energy Rating Scheme) rating
- Residential energy ratings are the basic tool that sets a mandatory minimum benchmark for the efficiency of all class 1 and class 2 residential dwellings ie free standing homes or townhouses on their own land; and apartments. The National Construction Code – Building Code of Australia (NCC-BCA) requires that these dwellings must meet the 6 star standard, which is an assessment of how energy efficient the design of the building fabric is. (The building fabric is the walls, roof/ceiling, floor, windows). The 6 star standard applies to class 1 and 2 dwellings Australia wide. The 6 star standard in Victoria also requires that class 1 dwellings have also have a 2000L rainwater tank or renewable energy hot water service. There are currently no such requirements on apartments.
- Potential dwelling rating scores range from 1 – 10 stars. A 1 star score is a very poor performing building, and a 10 star score indicates that the building would not require any energy to keep hot or cold in winter or summer ie this is as energy efficient as you could expect the building fabric to be and is similar in concept to the best practice renowned Passive house level of performance.
- Note the building energy efficiency rating does not take into account how efficient the heating or cooling units are in the dwelling, how people use heating and cooling systems, the energy efficiency of any of the lighting, other appliances or plug loads such as TVS and computers. The energy rating only assesses the energy efficiency of the specified building fabric for that dwelling.
- The rating assessment can be undertaken using any of the FirstRate5, Accurate or BERS rating tools.
- A HERS rating or a Part 3.12 Building Code deemed to satisfy assessment is mandatory for all new class 1 & class 2 buildings and extensions and is only available to residential houses and multi unit developments. HERS ratings are undertaken on the design of these buildings. Commercial buildings of class 3-10 cannot be rated using any of the three tools, and cannot obtain a HERS rating. BCA Section J assessments are required for such buildings.
2. BCA Section J compliance
- Compliance with Section J of the Building Code of Australia is mandatory for all non-class 1 or 2 buildings ie all buildings class 3-10. These assessments must be completed for commercial buildings to obtain a building permit. There is no star rating applied with these assessments, however a report is required to be completed to confirm compliance is achieve in relation to energy efficiency.
- Section J is a minimum standard and does not require improvement above the minimum. (Note the minimum standard will be improved in the 2019 BCA but the standard will still effectively be designed as a minimum. It is not a mechanism that rewards higher performance.
- Similar to the 6 star standard Section J compliance is a framework that is applied at the design stage although it is for all new non-residential developments.
- It is worth noting that the scope of the BCA to date has been to only focus on energy efficiency so other considerations such as stormwater management, water conservation, material selection, waste, transport, indoor environment quality, urban ecology, emission and innovation are not touched on by the Building Code regulations. Other tools such as the SDAPP program have been developed with an aim to address sustainability in these other areas, and addresses it to some degree in a range of other developments, but not all developments.
3. Sustainable Design Assessments for the Planning Process
- The SDAPP (Sustainable Design Assessment in the Planning Process) program is a Victorian council developed process to be applied to all buildings that require planning permits. Where applied it is mandatory to achieve satisfactory compliance. Approximately two thirds of Victorian Councils are now implementing the Sustainable Design Assessments.
- The SDAPP process is designed to apply to a wide range of development types. The BESS tool can be used to assess the sustainability of:
- individual houses
- extensions to houses
- multi-dwelling townhouses
- multi-dwelling apartments
- non-residential developments – office, retail, industrial
- mixed use developments
- The SDAPP program and BESS is has not typically been used on masterplanned communities or larger subdivisions for the following reasons:
- It is designed to assess and improve the sustainability of buildings and does not consider many elements relevant to delivering sustainable infrastructure. It considers on-lot solutions but not larger street-wide or precinct considerations such as encouraging appropriate density, connected active transport routes, the design or walkable neighbourhoods or sustainable materials selection.
- Most housing estate dwellings are individual houses. In growth areas zones planning permits are not required for individual houses, hence there is not a mechanism or process of referring new dwellings to councils for the implementation of the SDAPP program or BESS tool.
- SDAPP Fact sheets for each of the key sustainability areas identify mandatory requirements and Councils Best Practice standards.
- Where Green Star aims to lift the bar of the top end of developments, SDAPP looks to raise the standard of all developments that require a planning permit. Accordingly compliance certification is less demanding.
- Compliance with mandatory requirements or standards is demonstrated by submission of a Sustainable Design Assessment (SDA) or Sustainability Management Plan (SMP) depending on the size of a development. These assessments both generally use the BESS tool to quantify compliance, and written SDA or SMP to further explain compliance.
4. Green Star rating
- Green Star rating tools provides either a 4 star, 5 star or 6 star rating. Green Star is generally voluntary and can be used to assess most types of buildings. Four Green Star tools exist: Design and As Built, Communities, Green Star Interiors and Green Star Performance. Green Star – Design & As Built is currently the most commonly discussed Green Star tool, which assesses the sustainability attributes of a building through nine categories:
- Indoor Environment Quality (incl daylight, natural ventilation, indoor air quality-VOCs, acoustics etc);
- Land Use and Ecology;
- Emissions; and
- The GS Design and As Built tool replaces a suite of older similar tools that were building type specific, and which are now being phased out ie GS Multi-Dwelling, Office, Education etc.
GS is a relatively expensive process – lots of documentation to show compliance
- A 4 star Green Star building represents a building in the top 25% of buildings nationally in terms of its sustainable design. A 5 star Green Star building represents a national best practice building. A 6 star Green Star building represents a worlds best practice green building. Obtaining a Green Star rating is a voluntary accreditation. The process of achieving a Green Star rating is usually integral with the design of a building, and requires a lot of design consideration, time and document substantiation. It is not an in-expensive process and would practically mainly only be considered for projects above $3M in value or where the client has a very strong commitment to achieving a very high standard of sustainable design in their building.
5. EnviroDevelopment tool
- EnviroDevelopment (ED) is an alternative sustainability tool to Green Star that includes many similar goals.
- An established tool, it is substantially less expensive, faster and easier to implement than Green Star. The ED process is likely to take 3 months rather than 2 years as occurs with Green Star and accordingly is significantly less expensive.
- The tool is more commonly used on masterplanned communities and subdivisions, although it is also suitable for other building types: Seniors Living, Multi-Unit residential, Mixed Use, Industrial, Retail, Education, Health and Aged Care, Other.
- There are 6 elements to address In ED: Ecosystems, Community, Energy, Water, Waste, Materials.
- Currently only 4 of the 6 elements are required to be completed to achieve the minimum 4 leaf rating.
- The tool sets goals and requires statements to support how these have been met. It is not prescriptive, and is more flexible.
6. NABERS (National Australian Built Environment Rating System) rating
- NABERS unlike the above two rating tools is a performance based rating system for completed / existing buildings that relies on 12 months of operational data before a rating can be determined.
- NABERS assessments can be completed on the following building types: : offices (where their area is above 1000m2), hotels, shopping centres, data centres, and multi-unit apartment common areas. NABERS ratings range from 1 – Poor performer 2 – Below average performer 3 – Above average performer 4 – Strong performer 5 – Top performer 6 – Best practice.
7. Building Energy Efficiency Certificate (BEEC)
- Commercial building mandatory disclosure – under the national Commercial Building Disclosure program the owners of all commercial buildings over 1000m2 are required to undertake and disclose the results of a BEEC to prospective tenants or building buyers.
- The BEEC involves 3 components: a NABERS base building energy efficiency rating, a tenancy lighting assessment, and behavioural energy efficiency guidance. A BEEC is valid for 12 months.
- NABERS energy ratings which assess the infrastructure of the building, must not take into account Green Power.
- For further information on the mandatory Commercial Building Disclosure program refer to www.cbd.gov.au
8. One Planet Living tool
- The One Planet Living tool is an alternative to Green Star and like Green Star is suitable for larger projects. It takes a similar amount of effort to manage this certification process as a Green Star certification process.
- The One Planet Living tool is more goals focussed. It is established but not as commonly undertaken as Green Star.