By adopting passive design principles, we can effectively reduce a building’s energy consumption. In Brisbane, we are fortunate to live in a near-perfect subtropical climate, where it is possible for a well-designed building to be comfortable almost all year without the need for air conditioning or artificial heating.  Orientating a building effectively, maximizing the use of natural breezes and sunlight, effectively shading and insulating your building, and giving thoughtful consideration to building planning, can all work to reduce a building’s reliance on artificial systems and reduce your energy use.

Quantifying Energy Use

RESIDENTIAL  A number of tools have been developed in an effort to quantify the energy efficiency of a building. For residential buildings, the Nationwide House Energy Rating Scheme (NatHERS) is used. Under this scheme, energy consultants use plans and building specifications to input data into a NatHERS accredited software tool, which will generate a rating out of 10. A 1-star rating means that the home is energy hungry – and extremely inefficient. A 10-star rated home is extremely energy efficient. In other words, the closer to 10 the rating is, the less energy is needed to heat and cool the home.

In Queensland, new houses and townhouses must achieve a minimum 6-star energy equivalence rating. However, a better performing home should look to achieve 7.5 stars or above.

To encourage Queenslanders to switch off their air-conditioners and take advantage of the natural environment, the energy rating scheme provides optional credits for homes that have a deck, veranda or balcony that complies with certain requirements (adding a code-compliant roof and a ceiling fan). The idea being that the more time home occupants spend time outside (and become acclimatized) the less they are inclined to use artificial cooling.

COMMERCIAL  Commercial buildings must also meet certain energy efficiency standards. One of the leading measures used in Australia is the NABERS rating system (a 1-star to 6-star rating). The system provides a rating from one to six stars for buildings efficiency across energy, water, waste and indoor environment. The intention of the system is to provide a tool to understand a building’s performance across these elements compare to other similar buildings. Energy efficient buildings are generally rated above 4 Stars under the National Australian Built Environment Rating System (NABERS).

Why is this important?

Globally, the built environment accounts for over 40% of the world’s greenhouse gas emissions. Commercial buildings alone are responsible for around 25% of overall electricity use and 10% of total carbon emissions in Australia. The most recent IPCC report shows that we can mitigate climate catastrophe, but only through immediate and radical action. The Architect’s Declare movement in Australia is calling for all new buildings to be built to Net Zero emissions, which involves consideration of the entire building lifecycle, including its operational energy use.


Whether you are looking at a residential or commercial project, it can be prudent from a commercial perspective to seek to achieve building ratings that exceed today’s minimum standards. In addition to creating an energy-efficient building today, the building is likely to continue to be a “good performer” as rating standards increase over time. Reasons to be energy efficient:

Commercial buildings - owners

  • Increase building value by reducing the costs to operate and maintain the building
  • Helps to attract tenants and reduce tenant turnover
  • Potentially achieve higher rents and increased property value
  • Goes a long way to helping you be a good corporate citizen – meeting your goals for corporate, social and environmental responsibility

Commercial buildings - tenants

  • Energy efficiency means saving money on your energy bills
  • Enhancing your employee’s working environment Increases productivity
  • Goes a long way to helping you be a good corporate citizen – meeting your goals for corporate, social and environmental responsibility

Residential homes

  • Save money by reducing your energy bills
  • Increase the comfort of your home
  • Improve your health by living in a healthy building
  • Play your part in helping reduce our carbon footprint
  • Make a house that is more resilient to a changing climate

Increasing energy efficiency in existing buildings

Applying passive design principles to new building designs will help increase the energy efficiency of the project. But what if you are looking at renovating an existing building, what options are available to help increase energy efficiency?

Insulation, windows and draft proofing

A lack of insulation, poor draft proofing and aging windows can all contribute to excessive heat loss in winter and a building that gets too hot in summer. Addressing these elements – upgrading insulation, ensuring windows and doors are properly sealed and considering window glazing options can all contribute to a more energy efficient building.


Lighting accounts for approximately 12% of total residential energy consumption in Australia and is a significant part of the energy usage by a building. Consider switching the building lighting to a more energy efficient options (eg LED lights) to have an immediate impact on energy usage. Retrofitting the building to enhance the use of natural light, through the installation of skylights or new additional windows, can also greatly reduce an existing building’s reliance on artificial lighting.


Improving the energy efficiency of appliances and products has significant economic and environmental benefits, reducing running costs for households and businesses. The Energy Rating Label on appliances allows you to compare the energy efficiency and running costs of appliances before you buy.

Renewable Energy

Renewable energy from sources like wind, solar and hydro provide about 21% of Australia’s electricity supply. Today Australian businesses and householders have more options than ever to supply and manage energy for their buildings. Using a renewable source for your energy supply is a step towards a cleaner environment and responding to climate change.