Rebuild a chance to embrace green options

EASY ON THE EYE: What fun it would be to have a vertical garden growing up a Christchurch building.
EASY ON THE EYE: What fun it would be to have a vertical garden growing up a Christchurch building.

The rebuild offers Christchurch an opportunity to build energy-efficient, eco-friendly buildings for the future. So why aren't we?

Christchurch has a brilliant opportunity to build back better - not just safer, stronger buildings that may possibly be more attractive and useful than the old ones, but also more energy- efficient, eco-friendly buildings.

Houses, as well as public and commercial buildings, can be greener. The advantages include massive savings in running costs over the lifetime of the building; savings for the planet in terms of energy use and materials; and improved comfort for the occupants.

In the face of rising costs and a shrinking supply of fossil fuels, countries including Germany, Britain, Australia, and the United States are placing energy efficiency at the top of the agenda.

Christchurch could also be a leader. Unfortunately, many houses and buildings are going up with scant regard for alternative technologies. People may be genuinely unaware of what is out there, but also those in charge have failed to act.

Organisations such as EECA (the Energy Efficiency and Conservation Authority), Beacon Pathway, and the Green Building Council are doing their best to encourage a new approach. There are also some innovative companies. But politicians, both local and national, need to demand higher standards.

Meantime, home and building owners can take at least some steps themselves. Here's how.

Embrace passive design. This costs nothing other than a good architect. The building is simply oriented north for maximum sunshine. Judicious placement of windows and shading prevents overheating in summer and freezing in winter, thus slashing airconditioning and heating bills. Thermal mass, usually in the form of concrete, stores solar heat and regulates the temperature. Singapore's Changi airport has been given a makeover using passive solar design to keep the terminals comfortably cool without the need for expensive aircon.

Insulate. Install as much insulation as possible to minimise heat loss, boost comfort and cut costs.

Slap on some PVs (photovoltaic panels). Travel through the German countryside and you will see PVs plastered on the roofs of houses, public and commercial buildings. PVs, which utilise a silicon wafer to harness the free energy of the sun, have become a lot more efficient and cheaper. PVs produce DC (direct current). An inverter turns DC into AC (alternating current), which can be used to power your lighting and appliances, including perhaps a heat pump for space or water heating. PVs may not power the whole building all the time, but will cut costs. You can even feed surplus electricity back into the grid and get paid for it. Your house or office can become a mini power station.

Solar water heating also makes sense. The sun generates ample energy to supply the needs of the whole planet, free; the challenge is to harness it.

Install LEDs. Light-emitting diodes are an amazing technology that has come ahead in leaps and bounds. In January, 2011, I was lucky enough to take part in a tour organised by Philips Lighting to see LED lighting at the company's plant in Palo Alto, California, and at Color Kinetics, in New York City.

LEDs are approximately five to 10 times more energy efficient than incandescent lights and last 12 to 20 times as long. No wonder LEDs are being installed in buildings around the world (including the new Christchurch airport control tower).

According to Philips, "Widespread LED lighting use could potentially save 189 terrawatt hours (TWh) per year, eliminating the annual output of about 30 1000-megawatt power plants."

In 2009, President Barack Obama called for improving the energy-efficiency of more than 75 per cent of federal buildings and 2 million American homes.

LED bulbs in standard fittings are now available in New Zealand hardware outlets. They may cost more initially, but you will save big in the long term. Automated lighting controls also save energy and money.

Save water. With future droughts a virtual certainty, new buildings should be required to harness rainwater.

"Greywater" can be used for watering the garden or flushing the toilet. New subdivisions on the Kapiti Coast require water saving measures. Why not here?

Get planting. French botanist Patrick Blanc is an original guy. The author of The Vertical Garden (Mur Vegetal) has designed plant walls on highrise buildings around the world.

Not only do his buildings look cool and welcoming, the plants also create a unique microclimate. An Auckland based company, Vertical Garden, is doing the same thing around New Zealand. These are literally green buildings. Looking at greenery is a lot more restful than facing a sheer a concrete wall. What fun it would be to have a vertical garden growing up a Christchurch building! Have your say on architecture and the Christchurch rebuild. Email

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