Let’s go green by building green!
Being Green is easier than you think! An energy efficient home is good for the environment, reduces your cost of living and improves your lifestyle.
The importance of designing and building green energy efficient new homes now that will be sustainable in our future of ever increasing energy costs is huge. This has a three-fold benefit – to reduce your energy costs, to enhance your lifestyle through a more naturally comfortable home and to protect our precious environment for future generations. We are excited about research and development currently going on and new products that are continually being released to the market which assist us in our goal of making each home more energy efficient than the last.
The Building Code of Australia requires a minimum level of compliance in relation to energy efficiency. Queensland has a minimum 6-star requirement applying to all new homes, renovations and additions. At Watco Constructions we aim to achieve a higher level of environmentally friendly home than is required by the Code.
A house’s energy efficiency rating is determined primarily by the design of its building shell – its roof, walls, windows and floors. The rating is out of 10 stars with more stars indicating a more energy efficient and comfortable home.
Does a higher star rating mean a more expensive build cost?
While this can be true, the extra costs are generally offset by ongoing savings over the life of the home on household energy bills by reducing the need for artificial cooling.
Additionally there are many ways you can design your home to be more energy efficient which cost nothing such as considering the orientation of key rooms in relation to the sun at different times of the year. These considerations are known as passive design.
How does a higher star rating benefit me?
The higher the star rating the more naturally comfortable your home will be to live in. A more energy efficient home means lower energy bills as there is a reduced need for artificial cooling and less electricity being wasted by in-efficient light fittings or appliances. Reduced energy use also means a lower household carbon footprint so you can be confident you are doing your bit for the environment and to ensure our planets sustainability for future generations.
Energy Efficiency in Townsville’s climate
Queensland is home to several different climatic zones requiring different energy efficiency considerations. Townsville is located in Building Code of Australia’s climate zone 1 which covers Australia’s tropical areas. This zone is characterised by warm winters and hot humid summers with high summer rainfall. The main energy efficiency consideration when designing and building in Townsville is to cool the interior of the home all year round.
What is Passive Design?
Passive design is the key to sustainable building. It achieves this by using free, renewable sources of energy such as sun and wind to provide household cooling, ventilation and lighting, therefore reducing the need for mechanical cooling or lighting. This makes our homes more comfortable, saves us money and reduces environmental impacts such as greenhouse gas emissions.
Some key elements of passive design in the tropics are: designing a building to make the most of natural light and cooling breezes and using shading, orientation and appropriate building materials to reduce heat gain and storage. It costs little or nothing to incorporate passive design into a new building. The greatest benefits are achieved when passive design principles are utilised in the entire design and build process from site selection onwards.
Design considerations for building in Townsville
When designing for energy efficiency and comfort in this area, it is important to protect key living areas from the heat of the sun, to use lightweight construction materials which can cool quickly after the sun sets and to promote good airflow throughout the home. The following are some key design principles to bear in mind as you design your home:
- Orient the house and configure rooms to minimise direct sunlight and capture the prevailing breezes
- Allow the breeze to flow over and under the building shell to assist in cooling
- Carefully locate wall openings to allow breezes to flow through the interior of the home, including positioning internal openings to ensure cross-ventilation
- Consider the use of openings higher in the walls to allow rising hot air to escape and promote natural air movement. Higher ceilings also assist in removing warm air from the rooms lived in area
- Provide adequate shading to all walls, especially windows to minimise heat entering the home
- Use light coloured materials or paint on the roof and external walls to minimise heat absorption
- Use lightweight construction materials which do not store heat
Orientation and floor plan layout
- Townsville’s prevailing breezes come from the north-east, especially in summer. Ideally locate your main living areas and master bedroom to capture these breezes.
- In mid-summer, the south-eastern (morning sun) and south-western (evening sun) walls will be subject to direct heating from the sun. Consider locating the garage on the south-western side to take the brunt of the evening sun and position the living areas to the north-eastern side as they are mainly used in the evenings and will enjoy shade at this time.
Natural airflow and cross-ventilation
- Appropriate openings should be located to allow cooling breezes into the home. Use a combination of doors, louvre windows and other openable windows particularly along the north and east facing walls to capture the prevailing breezes.
- Good cross-ventilation is a key design element in the tropics and allows homes to be cool and comfortable without reliance on air conditioning. Internal openings should be located to enhance airflow throughout the home. Consider using timber blade louvre windows or louvre doors to improve airflow between rooms.
- Include ceiling fans to all areas to promote internal air movement.
- Eaves are essential for houses in Townsville’s climate. Combined with appropriately located outdoor living areas they assist in shading large windows and exposed walls. This is particularly true in summer when the sun is at a higher angle and has a higher heat index.
- Also consider landscaping as large trees can be utilised to shade key living areas.
- Avoid locating unshaded driveways and paving in front of prevailing breezes, as air passing over the surface will heat up before entering your home.
Insulation and material choices
- Insulation is important and can make a big difference to the comfort of your home and reduced energy bills. It can be used in both the ceiling and external walls to provide a barrier keeping the hot outside air out and the cool inside air in. Not only will insulation keep your home at a more stable temperature but it can reduce street noise from entering the home. Choose insulation with a higher R-rating to increase your level of protection.
- Lightweight timber frame construction is ideal for Townsville’s climate as it is more responsive to changes in temperature. Once the sun sets it will cool quickly unlike masonry products that can retain the suns heat for quite some time and release it into the home during the night.
- Lighter colours tend to reflect rather than absorb the suns heat. Recent studies have shown that a light-coloured roof can have approximately 30% lower heat gain than a dark roof. Consider using lighter colours for your exterior paintwork, roof and window frames to reduce the amount of heat entering your home.
- Roof-space ventilation is another key factor in keeping the heat out of your home. When roof-spaces are poorly ventilated the trapped air can get as hot as 70deg and this in turn conducts heat through the ceiling into the living areas below. In Townsville with over 300 days of sunshine a year, ventilating your roof-space can make a big difference.