Green is good

Once, building or renovating was about creating a dream home. Now it is just as important to create a ‘green’ home. With a bit of thought and planning your house can be kinder to both the environment and your hip pocket.

Before deciding what to tackle first in greening your home, it’s important to understand where the most energy is used.

According to the federal Department of Environment, energy use in the home can be roughly broken down into:

• Heating and cooling: 40 per cent (houses in cooler areas generally spend more on heating than those in warmer regions spend on cooling).
• Electrical appliances (including standby, refrigeration and cooking): 33 per cent.
• Hot water: 21 per cent.
• Lighting: six per cent.

Whether you are building, renovating or just looking to reduce your carbon footprint, there are a few things you can do to make your home more eco-friendly.

Good design is one of the simplest and most effective ways to slash hundreds from your energy bills by using the sun to heat and the shade to cool.

Retractable awnings, blinds and deciduous plantings can all be used to shade windows in summer. In winter they simply retract, or drop their foliage, to allow sunshine to stream in.

The Australian Government’s Your Home website (www.yourhome.gov.au/ passive-design/glazing) suggests incorporating some simple principles at the design stage of building to optimise the thermal performance of your home.

• Locate and size windows and shading to let sunshine in when the temperature is cold and exclude it when it’s hot.
• Use thermal mass to store the sun’s heat and provide night-time warmth in cold conditions.
• Locate window and door openings to allow natural cooling by cross-ventilation.
• Provide seals to openings to minimise unwanted draughts.

Solar energy has, rightfully, taken off in Australia as we have some of the world’s longest sunlight hours and highest electricity prices.

The major factor driving prices is a massive spike in electricity usage between 4-8 pm,1 thanks to our love affair with all things electronic. Spending on infrastructure and supply is focused on supporting this four-hour surge.

That’s why one of the biggest developments in the photovoltaic (solar energy conversion) market is residential energy storage. That is, affordable home batteries capable of storing solar-generated power for use (or sale back to the grid) during these peak periods.

Two major ways to save water are rainwater tanks and grey water recycling.

Australian Bureau of Statistics data indicates we pay around $584 a year for water. A diversion switch (starting at around $150) to send grey water from sinks and showers to be reused in the garden, can reduce water usage by 30-50 per cent. More elaborate grey water treatment systems (upwards of $3,000) allow for reuse in cisterns or washing machines.

Rainwater tanks (from around $700) can also be plumbed in to supply toilets and laundries.

Public health laws sometimes limit how grey water can be used, so check with state and local authorities before installing a system.

The Tankulator site (http://tankulator.ata.org.au/) run by the not-for-profit Alternative Technology Association is a good place to start any research.

Solar hot water systems may deliver the cheapest hot water, but there are also high initial costs. Savings may also be possible using cheaper eco-systems, such as heat pumps, which use ambient air temperature to heat water. For an idea of costs and savings, the Victorian government has published comparisons on its Sustainability Victoria website which lists the average annual running cost of various systems in a two-person house using 100 litres per day. A solar system (boosted by natural gas) averaged about $91, compared to a heat pump system at $203; gas storage (natural gas) at $219 – $275 and off-peak electric at $508 and gas storage (LPG) at $629.

Choosing a sustainable, insulating building material is an essential part of an energy-efficient home.

Another recent development in ‘smart’ building materials are integrated solar panels, such as solar roof tiles and semi-transparent panels, which can be used as skylights. Thin film photovoltaic technology is also being used to develop cost-effective ‘solar coatings’ for other building materials. For more information on sustainable building materials see www.ecospecifier.com.au

The latest high-end trend in environmentally friendly pools is the ‘natural pool’. Relying on shallow planted areas to filter water naturally, they are both beautiful and green, although they cost more than standard pools to build, and require more space.

If you have a conventional pool, consider heating it with solar hot water panels or solar absorbing pool covers rather than relying on conventional pool heaters. And a cover on the pool when it’s not in use can reduce evaporation.

The average household spends about $2,000 a year on electricity. Appliances left on standby can account for as much as 10 per cent of your bill. Master/slave and ‘intelligent’ power boards are available to cut mains power when devices are not in use.

On new builds it is also possible to install a master switch (similar to systems used in hotels), which turns off all non-essential appliances. Most power companies also offer you the option of receiving some, or all, of your energy from renewable sources for a higher charge.

Make sure you look at the Energy Rating stars of appliances before buying, and only purchase what you need.

Planting out a native garden not only attracts wildlife, but can reduce the need to water. Check out council plantings in your local area, as these will be suited to the climate. Many councils run free native plant programs for residents.

Previous research by NASA suggests that certain indoor plants such as the peace lily provide a natural way of removing toxic agents such as benzene, formaldehyde and trichloroethylene air, helping to neutralise the effects of sick building syndrome.2

Furthermore, vegetables and fruit grown from your own window box or garden bed are fresh, can be grown organically, and limit the need for environmentally harmful transportation measures.

For a list of rebates available in your area see: www.yourenergysavings.gov.au/rebates