In the Building Process

In designing a home you would take account of its energy efficiency:

• Is it easy to heat and cool – well ventilated, well sealed and insulated, with appropriate solar orientation.

• How do its fittings perform on energy efficiency – its hot water system, its lights, its stove?  How much control does the user have to reduce their power use?

• Is it fitted with solar panels and/or batteries to reduce the use of fossil-fuel generated energy?

 

While these questions are most important for the ongoing sustainability of the home, and also reduce the cost burden on your tenants, it’s also worth giving some thought to the emissions generated during the construction.  This includes:

• Looking at your building materials – how much energy is spent making them, what natural resources go into them and how are these renewed and replenished?

• How far did your materials need to travel to get to the building site, and what were the emissions from this transport?

• What was the impact of your construction on vegetation on site, and were losses offset or replaced?

 

Rating Schemes

There are a number of rating schemes in use in Australia which can help you to certify the impact of your buildings.

The Nationwide House Energy Rating Scheme (NatHERS) is a scheme administered and overseen by the Commonwealth Government which helps builders and owners rate the energy efficiency of new housing.  Housing is assessed at the design stage and rated on a scale of one to ten stars (ten being the most energy-efficient) based on a complex set of criteria.  The assessment is carried out by certified assessors using a software system developed for the scheme.

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While NatHERS ratings are not compulsory, the National Construction Code contains minimum standards relating to energy use and a NATHERS rating is one way of demonstrating a home meets these standards.  For houses, a six-star rating satisfies this requirement, while for units a minimum is five for any one unit and six average for all units in a complex.  

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NSW, which always likes to be different, has its own home energy rating scheme which is compulsory for new homes.  It’s called The Building Sustainability Index (BASIX) and fulfils a similar role to that played by NatHERS nationally.

 

There is also a broader-based scheme, the Green Star Rating Scheme, which has been administered by the Green Building Council of Australia since 2003.  Unlike NATHERS and BASIX, this scheme rates both commercial and residential buildings and focuses on a wider range of environmental sustainability questions.  It involves four types of ratings – for buildings, whole communities, interiors and existing buildings – and rates projects on a six-star scape, with four stars and above being granted ‘Green Star’ accreditation.  While the scheme can operate at multiple levels it is particularly appropriate for larger projects.