Building a ‘green’ kitchen involves more than just installing energy and water rated appliances and fixtures. A truly sustainable kitchen starts from the ground up, including everything from sustainable cabinetry to non-toxic finishes and glue.
Choosing sustainable materials
If you're serious about building a green kitchen, you'll need to consider how each product and material stacks up in terms of its health and environmental impact. Products must be durable and low maintenance, so that they'll stand the test of time and won't require the use of too much extra energy.
As well as considering what your kitchen's made of, consider the source of the materials too. If you're building with wood for your benchtop or cabinetry for example, ensure that it's FSC-certified plantation timber, recycled or reclaimed timber rather than virgin rainforest timber.
Life cycle analysis
As well as thinking about the types and source of the materials, it's a good idea to consider the environmental impact of the production and extraction of raw materials, and the toxic and greenhouse emissions generated by their manufacture, use and transport. A proper assessment of the total energy used is called a 'life cycle analysis' (or 'life cycle assessment'). This isn't always easy to quantify, but some manufacturers will provide this information, and you can normally get a rough idea by investigating the manufacturer's methods, and by considering things like materials, transport and packaging.
Using heavy materials that have been shipped from the other side of the world, for example, incurs a fairly heavy cost in terms of the amount of fuel that's used to ship it. Locally sourced materials are likely to incur far less in terms of transport pollution. To be truly green, you'll ideally need to look at renewable products with recycled content and a low embodied energy.
Volatile organic compounds
Try and use materials that don't involve the production of noxious chemicals - this is as much for your health as anything else. Natural, non-toxic and low-allergen materials can be used where possible, and all joinery products should ideally employ low VOC (Volatile Organic Compound) materials. Volatile organic compounds are toxic chemicals that evaporate out of certain products such as adhesives, paints and lacquers.
For example, benzene is found in paints and glues, polyurethane is found in two pack finishes and formaldehyde can be found in the adhesives used to manufacture particleboard, fibreboard and plywood. The Australian government says that exposure to formaldehyde may result in eye, nose, throat and lung irritations and allergies - and it's classified as a category 2 carcinogen.
When you're choosing water appliances, ensure they are AAA rated or equivalent. Select your appliance based on the maximum star rating within your budget. A water efficient tap fitted with an aerator might discharge 2 litres of water a minute, whereas a regular tap may discharge anywhere up to 18 litres per minute - which is a pretty huge difference!
Kitchen appliance energy efficiency
All major kitchen appliance products now have labels that rate them according to how efficiently they work - this includes dishwashers, refrigerators, ovens and microwaves. All products available at Australia’s major retailers are energy-efficiency approved before going to market. Efficiencies have improved by orders of magnitude over the past decade, and they're set to get even better.
By law, retailers must display the energy rating label. These labels provide an indication of cost of power and energy. This has become a major consideration when buying an appliance, driven as much by people's concern for the environment as it is by rising electricity prices.
Take a fridge, for example. It must display a MEPS (Minimum Energy Performance Standards) label showing efficiency in terms of a star rating. Products are tested by a National Association of Testing Authorities accredited laboratory, and the more stars displayed, the lower the kilowatt hours (kWh) that are used.
Dishwashers are rated both in terms of how much water they use, and how much energy they consume. The most energy efficient dishwashers are those which have energy saving features such as time delay, which switches on and off depending on peak times. It's expected that by 2016 a WELS efficient dishwasher could save nearly 1200 megalitres a year. This represents a reduction of about 6.5 per cent in the water consumption of the dishwashers sold between 2003 and 2016.
If you have solar panels on your roof, you'll most likely be critically aware of your house's energy consumption anyway...
Energy efficient lighting
Lighting is something you'll need to consider as well. Where possible, daylighting will help to fill your kitchen with bright, natural light, and designing with skylights and windows will ensure you don't need to use electricity during the day. Energy saving LED or CFL globes designed to provide task lighting will help to efficiently illuminate your kitchen when the sun goes down.
Gas efficient appliances
Gas cooking appliances come with efficiency labels too. Label requirements and relevant performance requirements are specified in AS 4551 (AG 101) Domestic Gas Cooking Appliances. Gas energy labels are similar to those found on electrical appliances, except that they're blue in colour and show annual energy usage in megajoules (MJ). The gas labelling program is currently an industry voluntary scheme.
Talk to an efficiency consultant
Building a seriously efficient and sustainable kitchen's a complicated affair. While most of us won't have any trouble choosing efficient appliances (thanks to star ratings schemes), things become a bit murkier when it comes down to figuring out what sorts of products, materials, fastenings and surfaces are sustainable, where they've come from and how they've been produced.
If you're deadly serious about building a sustainable kitchen, talk to a sustainable design expert. Pre-packaged enviro-kitchens are available too - these will invariably cost more to install than your average kitchen renovation, but they may well save you money in the long term.