Meet a city community that combines high-density living with open space.

SIX years ago, Jo Thomas moved into Adelaide’s CBD – but not into a lonely, city shoebox. She moved into Christie Walk, a residential development on the site of an old bottle-recycling depot. On land the size of about three suburban blocks, there are now 27 apartments and townhouses.

“I work long hours in my job as a doctor and when I first came here my daughter was still at school,” she says. “Her grandparents lived here too and she really liked being close to them, but she also had a lot of other people around, with diverse interests. It was good company for her.”

Christie Walk is included in a new book by American architect Ross Chapin, called Pocket Neighbourhoods: creating small scale community in a large scale world.

In a pocket neighbourhood, Mr Chaplin says, houses or apartments are grouped around shared open space, which can be a courtyard, a lively pedestrian street, or even conjoined backyards. There, residents will meet by chance and children can play safely.

Dr Thomas believes living at high density would be much more difficult without that kind of design. “We can stop and chat if we feel like it, or share a meal in the community room,” she says. “We know each other, but we have our own private space and dwellings. It’s the best of both worlds.

Despite a narrow, awkwardly shaped block, the layout of Christie Walk feels open and lively. There’s no driveway through the site. Instead, plants cover about a third of the space, including a deep rooftop garden and a vegie patch. The buildings also far exceed the minimum efficiency standards; residents’ utility bills come in at one-third to one-half of the state’s average.

Urban Ecology, an advocacy organisation founded by Christie Walk residents, has just released a short film and information pack, a decade after they ran their first site tour.

The project’s architect – and a former resident – Paul Downton, says the group set out to inspire better cities.

“We wanted to build something that recognised the city as a positive thing: not a problem to run away from, but a solution to walk towards,” he says.

“In terms of making great places to live, conventional development has missed the point completely. The pocket neighbourhood idea is a way of putting people back in touch with each other without rubbing their noses in it.”

Mr Downton says the idea of “connection” was a key to the design. “You can do it anywhere and everywhere. It comes back to recognising what humans are all about: we are not consumers,” he says. “Development should be about making us better able to enjoy life and connect with each other and the natural environment. Those are big aspirations, but they’re achieved through tweaks at the immediate, local level.”

The scope for this kind of change isn’t limited to new projects. In existing neighbourhoods, a good way to remove social barriers is to keep our physical barriers low.

“If you’ve got a six-foot fence out the front and you can’t see the street, you’re not going to make much connection there. Or compare backyards that are sealed off with ones where the kids can still see each other and ask each other to play,” he says. “Little changes can make a big difference to relationships.”

Read this article at The Age online

Why cycling will get you fit and green

BRUNSWICK resident Rosy Strong rides her bike to work in Richmond. “It means I don’t have to think too much about exercise or going to the gym out of hours,” she says. “My ride to work becomes my hour of daily activity.”

Around the offices of Bicycle Victoria, says Bart Sbeghen, they call this “the extra Tim Tam factor”.

“A lot of people ride for convenience and then they realise they’ve got the health benefit. An extra Tim Tam a day – it’s all justified,” he says.

Mr Sbeghen says there’s been a steady rise in commuter cycling numbers around Australia. “Riding to work just keeps going up and up, especially in the capital cities. Melbourne’s inner-north has almost one in five people riding to work. And the number of cyclists on Swanston Street lately is equivalent to more than 40 trams a day. It’s getting to be like a European city.”

If climate change is a diabolical policy problem, then cycling is one of the saintly solutions. Pedal pushing is an antidote for several modern ills, from greenhouse gas emissions, air and noise pollution, and traffic congestion, to obesity and social isolation.

“It’s a big cost saving too,” Mr Sbeghen says. “In some cases, people can give up the second car, or their monthly public transport ticket.”

But while inner-city residents can cruise on easy streets – especially in Melbourne’s north, which has a web of bike lanes – the roads are rougher for cyclists elsewhere.

Mr Sbeghen is working on design guidelines for new housing estates to make sure developers consider the needs of bike riders, such as direct links to shops, schools and public transport. With smarter planning, he says, cycling can fit in with local errands or make up one leg of a longer commute for people in middle- and outer-ring suburbs.

“Not all jobs are in the city, and shops and schools are always local,” he says. “Trips of between two and five kilometres are in the sweet spot where riding beats any other way of getting about.”

To find out about cycling in your area, contact your local Bicycle Users Group. On its website, Bicycle Victoria has a long list of BUGs and cycling clubs. “They’re popping up everywhere,” Mr Sbeghen says. “BUGs are independent and they talk to local politicians about what they want. It’s making for a much healthier city.”

If you’re hesitant about getting into the saddle, consider cycle safety training. Ms Strong’s business, Bikes@Work, runs regular courses for the Darebin, Booroondara and Whitehorse councils, as well as for individuals.

She says the idea of riding in traffic can be intimidating. “One rider said to me, ‘In a car, you’ve got metal wrapped around your skin, but on a bicycle, it’s skin wrapped around metal.’ People feel there’s a lack of protection.”

But that sense of vulnerability can become a strength, if you ride with it in mind. Ms Strong advises bike riders to use lots of lights and reflectors. “And you need to be looking around you all the time, observing and anticipating what could happen,” she says.

“Position yourself in a predictable, visible place on the road. Keep a metre out from the kerb or from parked cars – never assume drivers will watch for cyclists before they open their door.”

Read this article at The Age online

Too much light is damaging to our nights

ON Thursday, Friday and Saturday evenings, when the sky is clear, Jack Mack lugs his telescope, computer, card tables and folders to the front of his Abbotsford home. He positions a sandwich board, which reads: “Welcome to Footpath Astronomy”.

He’s been doing this for four years, on Nicholson Road, next to the Retreat Hotel. “It gives people an opportunity to see the moon, a planet or a star cluster through a telescope,” he says.

Most city-dwellers notice the moon and nothing more. “People walk past and I say: ‘Sit down here and look in the eye piece’. And they’re absolutely blown away. Saturn is the crowd favourite, because you can easily see the gap between the planet and its rings.”

In 1610, when Galileo observed for the first time that the Milky Way was made up of individual stars, our galaxy was so bright it cast shadows on the ground. Now, from where we live, most Australians can’t see the Milky Way at all.

Mr Mack is a member of the Astronomical Society of Victoria, which has a dark sky viewing location near Heathcote in central Victoria. Even from there, the glow from the city encroaches upon the sky.

“It’s light pollution,” he says. “At least in the bush you can see the Milky Way with the naked eye. As you get closer to the city, the light gets denser and you see fewer and fewer objects.”

That’s not the only adverse effect of light pollution. Mark McDonnell, director of the Australian Research Centre for Urban Ecology, says it’s a threat to biodiversity and alters animal behaviour and feeding habits.

“Night-flying insects cannot resist the light. Research from Europe has shown a dramatic reduction in the number and diversity of insects, particularly moths, in cities when compared to the village-farmland edge. They estimate billions of insects are dying,” he says.

“It not only reduces food sources for animals, but also it reduces the number of pollinators. Light pollution also affects when plants flower and when they go dormant for the winter.”

The International Dark-Sky Association website carries useful guides on light pollution and residential lighting. Mr McDonnell believes householders can take a lead in reducing its harmful effects.

“We shouldn’t have lights that shine up. Some homes are lit up like landing fields around doors, paths and garages. We can shield lights so they’re only directed downwards. We can use motion detectors and timers to switch lights off when no one’s around.”

All our lighting also sucks energy. Last year, the Municipal Association of Victoria launched the Give our streets the green light campaign, aiming to secure state and federal funding towards the up-front cost of more efficient street lights.

It estimates that better globes and fittings would cut lighting energy use by over two-thirds and cause three to four times less light spillage.

Mr Mack, flanked by two freeways, the city and the MCG, says light pollution is bad and getting worse. Even so, he can still summon wonder among passers-by. On a good night for seeing, he shows the moon. “I do it from a low magnification first, then I put in a higher power and they’re looking inside a sea pockmarked with craters,” he says. “The moon is just as fascinating as anything in the solar system.”

Read this article at The Age online

Plane travel is the forgotten baggage on the green-home carousel

The carbon footprint of a return flight to London is about the same as the average household’s yearly carbon footprint, according to Moreland Energy Foundation.

When Helen O’Shea, from North Fitzroy, first heard about the greenhouse impact of flying, the information stopped her in her tracks. “Like many other people, I’d changed the light globes, got solar panels and reduced my driving,” she says. “But I realised you can’t take a holiday from that once a year and virtually double your carbon emissions.”

So, four years ago, Ms O’Shea decided not to fly.

She retired recently, after a career in academia in which she had worked around Australia and overseas. “I have friends on the other side of the world who I’d dearly love to see every year, but if I’m serious about adapting my lifestyle to the needs of society and the planet, then I think I can’t do that,” she says.

“Like every resolution, it stands to be broken, but I’ve set myself a goal – and it’s a journey in itself.”

As a part of its Zero Carbon Moreland project, Moreland Energy Foundation coordinates activities and retrofitting deals to help people go green. In the last few months, the campaign has focussed on transport, encouraging residents to take public transport, walk, ride and car-share.

Asha Bee-Abraham, from the foundation, says that if we’re serious about reducing our emissions, we must also think twice about long-haul travel.

“Flying does matter. It’s a difficult issue, because it’s become more and more accessible. And as we’ve globalised, our relationships have spanned the world.

“We’re not asking people to give up the air cold-turkey, but encouraging them to pause and think before they book a flight. Can you have a similar experience more locally, or travel by train or bus instead?”

In the office, she says, workers can try video conferencing instead of scheduling interstate or overseas meetings.

The foundation compared the greenhouse emissions of a journey between Melbourne and Sydney by plane, bus and car, with different passenger numbers. For just one person, driving came out worst, followed by plane and bus. But with a full car, driving was the most efficient.

Ms Bee-Abraham says that although offsetting your flights can be worthwhile, you must do your research. Costs and calculations vary widely, depending on the kind of offset and its assumptions about the aircraft’s load and efficiency, and the effect of emissions at high altitudes. The Carbon Offset Guide website recommends making sure the offsets are independently verified and comply with recognised standards.

(For an alternative take on offsets, visit Cheatneutral, a satirical website which allows cheating partners to balance their infidelity by sponsoring the celibate or monogamous.)

Throughout May, Ms Bee-Abraham is running a local adventures campaign. “Travelling broadens our perspectives, but there are ways we can travel that don’t involve flying. In Melbourne we’re surrounded by beautiful scenery and national parks, as well as places where people can pamper themselves and see things that are very different to our day-to-day lives,” she says.

Likewise, Ms O’Shea says her resolution hasn’t meant foregoing all fun. “If I want to visit friends or have a trip, I take the train and turn holidays into a time where the travel itself is a big part of the adventure.”

Read this article at The Age online

For extra inspiration, obey gravity with short story writer Laura Jean McKay. She’s blogging about a year without flying.

Why big households are better than big houses

OVER the last century, Australians have lived increasingly alone. When the first national census was conducted in 1911, an average of 4.5 people lived in each home. By the most recent census, the number had nearly halved.

But at the same time, we’ve been building bigger houses – a report by CommSec in late 2009 found our new dwellings were the world’s largest – and affordability has fallen.

As permaculture founder David Holmgren summarises: “We’ve got bigger houses, with more stuff and fewer people in them.”

Proportionally, smaller households use more energy and create more greenhouse emissions than larger ones.

“As you get down to double- and single-person homes, the efficiency of the household economy falls,” Mr Holmgren says. “Food preparation, food wastage, heating, cleaning and maintenance all become a bigger load for less benefit.

“And when it comes to more self-reliant living, in a small household you can’t do as many things, like growing and preserving food, keeping animals, or your own building and renovation.”

He notes that not only are fewer people living together, but we’re also spending fewer hours at home. The combination forces ever-more development, jams our transport systems and exacerbates social isolation.

“Our cities are crowded by empty buildings under lock and key, with people racing between them – whether it’s to work, the gymnasium, the restaurant or the childcare centre,” he says.

Given the spare capacity in existing housing stock, he argues the case for “higher density living”, not higher density building.

Bigger households, where people are home more often, are likely to be consuming less, producing more of their own needs and contributing to the vitality of the local area.

So how can we live in larger numbers? Mr Holmgren says the two most common ways are to take in boarders or share with extended family.

“From a hard-nosed, self-interested perspective, if you’re a homeowner with a mortgage, renting the spare room out to a boarder is the best thing you can do to reduce your debt burden,” he says.

Likewise, Ed McKinley, of the Groupwork Institute of Australia, argues young people should consider the financial, social and environmental plusses of teaming up to buy a house.

“It’s one way younger people can enter the market and still live in the groovy parts of the city,” he says. “There are big blocks around with enormous scope to be cleverly reconfigured to meet individual, family and group needs.”

From this Friday to Sunday, the institute is running a short course on living and working well together. Mr McKinley draws expertise from nearly three decades living at the Commonground community, near Seymour.

“People are frightened it won’t go well and they won’t get their own space. They’re real concerns, but you can make agreements upfront,” he says. “You can be clear about what is going to happen when someone leaves or if people get into conflict. You can set up good processes and expectations to deal with those things.”

And while the concerns are real, so are the benefits. “It’s about having one block working a lot harder,” he says. “You might need to work less to afford that location. Your utility costs drop dramatically and you may have more capacity to install things like solar panels or solar hot water.”

A new web guide will help straighten your irrigation

MELBOURNE has begun 2011 with record rainfall, but there’s no guarantee that the lush times will continue. The Bureau of Meteorology predicts that the La Niña conditions that brought the big wet will dissipate by wintertime.

By historical terms, the city’s dams are still low, and stage two water restrictions will remain at least until spring. That means householders still aren’t allowed to water their lawns from the mains. Gardens, however, can be watered by hand at any time, or every second day, at specified times, with manual and automatic irrigation systems. (You can find the full details about stage two restrictions on the Melbourne Water website.)

Geoff Connellan, from the University of Melbourne’s School of Land and Environment, says that just because we can water more often, doesn’t mean we should.

“The most common mistake people make in their gardens is to over-water, because they don’t understand how much water different plants need and how much moisture can be stored in the soil,” he says.

Together with Dr Jon Pearce and a team from the university, Mr Connellan has spent five years developing a free, online tool, called Smart Garden Watering, which helps you understand how to give your garden the right amount of water at the right time.

Using the website, you can calculate your water needs by entering all the details of your garden, including the location, size, slope and soil conditions, as well as the watering method and the types of plants and mulch.

The program draws on localised climate data and soil conditions, together with a database called the Burnley Plant Directory, which comprises over 1500 Australian and exotic plants.

Because it requires such detailed local data, the system is only available to residents in Melbourne and Geelong – for now, at least. “It does calculations for your postcode,” Mr Connellan says. “That’s important, because if you think of a garden in Sunbury and a garden in Olinda, they’re two totally different scenarios.”

The site is sprinkled with facts and features. It includes a Facebook application as well as maps, photos and forums that allow users to see other people’s gardens in their area, contact the gardeners and learn from each other’s experiences.

You can also plug in the details of your water tanks and see their likely storage levels throughout the year, based on the irrigation needs of the garden.

The results can be used not only to help you better understand your plants, but also to see what would happen if you re-designed your backyard. The website is interactive – you can toy with the settings and see how they affect your water consumption.

“It’s a sophisticated tool, but we’ve found that once people have become used to it, they are happy to play around with the options,” Mr Connellan says. “For example, if you choose drip irrigation or spray irrigation, or mulch or no mulch, you can see the consumption changing.

“That’s a very powerful graphical tool for a user. It encourages people to select efficient irrigation methods, and plants with low water needs.”

As a general tip, Mr Connellan recommends drip irrigation systems, underneath a layer of mulch of between 50 and 75 millimetres.

“Most people with plumbed watering systems can save about a third of the water they’re using, if they water wisely.”

Read this article at The Age online

To find the right solar panel, you can’t beat thorough research

THE rebate for residential solar panels has changed, yet again. From the start of July, the cash back available from the federal government will be cut by between $2000 and $2500.

Solar retailers and installers are experiencing a rush of demand before the fall. Many are already booked up until the new financial year, and those that aren’t yet are warning customers to get in quickly.

So if you’re considering purchasing a solar photovoltaic system, it’s worthwhile investigating your options now. But if you miss the deadline, all is not lost – prices may not rise too much.

The federal rebate is based on the trading value of ‘small-scale technology certificates’ (formerly known as RECs), which are created when solar hot water and solar electricity systems are installed. Presently, householders receive a credit of five times the certificate price, but the recent glut of installations has meant that the price – and therefore, the rebate – is lower than usual.

The multiplier will be cut to three from mid-year, and progressively reduced until 2013.

Russell Marsh, policy director at the Clean Energy Council, says the strong Australian dollar and falling costs in the industry mean that despite a smaller rebate, the price of a system won’t increase significantly in the second half of the year.

“Costs are coming down quicker than most people expected. The market is booming – there could be nearly 300,000 houses with systems on their roofs before the end of this year. We suspect [the rebate change] will have a small impact on price,” he says.

Mr Marsh says a good quality, 1.5-kilowatt system will set you back about $4000, out of pocket, depending on installation costs. For an average household, the payback period is around seven years.

If your head isn’t spinning already, you also need to consider the state rebates, known as ‘feed-in tariffs’. In Victoria, power retailers credit panel-owners 60 cents per kilowatt-hour for any surplus energy they feed into the grid (for the next fifteen years).

But new owners may soon miss out. “That premium tariff has a limit and we expect it to be reached within the next six months, or sooner,” Mr Marsh says.

Of course, there’s much more to consider than prices and rebates. To help, the Clean Energy Council has produced a detailed guide to buying solar panels. It covers basic information about the technology and its suitability for your home, together with a checklist for installation and comprehensive lists of questions to ask retailers and tradespeople.

For even more information, try the articles and podcasts put together by Choice.

Ingrid Just, from the consumer advocate, says a 1.5-kilowatt system produces about a third of the energy used by an average household.

“Firstly, get into the habit of reducing your energy consumption,” she says. “Australians tend to use a lot of electricity, so you should look at how much panel capacity you actually need.”

Before you buy anything, be sure to research thoroughly: ask your energy retailer about the tariffs it offers panel-owners and get quotes from a number of retailers and installers.

“Make sure you’re using an accredited installer and that any panel you consider meets Australian Standards,” she says. “Look for a warranty of 25 years from a company you trust.”

Read this article at The Age online

A mix of ingredients will put your compost on the top of the heap

GARDENING guru and landscape architect Costa Georgiadis can’t get enough vegie scraps. To feed his chooks and worms, and his compost pile, he imports peelings from neighbours.

“I’ve got a bin at the front and another one on the side street and my neighbours drop their scraps in them,” he says. “It’s a wonderful resource and everyone has it.”

Today marks the start of International Composting Awareness Week. To celebrate, Cultivating Community and Yarra City Council are holding a ‘Composter’s Composium’ next Saturday, May 7, at Smith Reserve in Fitzroy, from 11 am. The event will be a humus-inducing extravaganza, complete with live music, a workshop by Mr Georgiadis and (nearly) every kind of composting contraption known to urban living.

Lisa Coffa, senior waste officer at the council, says organic waste still comprises over half the kerbside collection, by weight. “It imposes great demands on our infrastructure and requires a lot of resources to pick up,” she says.

But that’s not all – every tonne of green waste in landfill causes about a tonne of greenhouse gas emissions. Ms Coffa says composting is a low cost, low-tech, local solution. Most councils, including Yarra, offer residents a discount on worm farms and bins, as well as advice on how to do it right.

“For most people, it’s very easy to convert green waste into something productive,” she says. “If you’re composting, you are better connected to your food source. It makes the link between what you purchase and what you throw away.”

For his part, Mr Georgiadis likens composting to cooking. “When you make compost, you transform the ingredients into something edible, with the help of microbes and worms and plants. You’re actually a chef, cooking your own chemical-free elixir.”

His first tip is to prepare well. “Compost gets a bad wrap when people do it half-heartedly,” he says. “You need to have the ingredients on hand, otherwise you’ll end up with a lasagne that only has pasta in it – and then it will become a seething, smelly, gooey mess.”

In the kitchen, get yourself a sealable container to stop vinegar flies from invading. In the garden, choose a shady spot and set up dedicated, covered spaces for several materials. You’ll need to mix the nitrogen-rich kitchen scraps with carbon-rich brown stuff, such as dried leaves, straw, shredded paper and cardboard.

Other items on Mr Georgiadis’ recipe include manure, green garden clippings, rock minerals and soil. Make sure you’ve also got a watering can handy and a corkscrew-style aerator (about $20) or garden fork for turning the heap.

“The key to any composting system is diversity, so every time you add something, add some of the other elements as well. Water it, turn it, cover it and let it do its thing,” he says.

Once the bin is full, you’ll need to leave it for about two months (but keep turning it every week) while you start a second batch.

When it’s done, to test if your mix is right, Mr Georgiadis suggests grabbing a handful. “If you squeeze firmly, you should see a little liquid running along the bottom of your pinky. If a whole lot of juice comes out, you need more carbon material; if nothing comes out, you need more water.”

Read this article at The Age online

Old electronics are too valuable to be dumped

IN Life Pscycle-ology, a short animation by Leyla Acaroglu, a forlorn mobile phone named Eric Sun laments his future stuck in a desk drawer. He is only one year old.

But poor Eric Sun’s plight is just the tip of the landfill. According to Greenpeace, e-waste now comprises five per cent of global municipal waste, nearly the same amount as all plastic packaging.

Ms Acaroglu, from Melbourne design consultancy Eco Innovators, says only one out of every 100 discarded mobile phones is recycled.

“The way we use and abuse high-end goods is very inefficient,” she says. “They contain hazardous substances that escape into the waterways or leach out in landfill. It’s wasteful and unfair to future generations – we’re gobbling up valuable resources so we can all have the latest iPad.”

Unfortunately, pollution and waste aren’t the only worries. Our throwaway electronics have side-effects all along the production line, from allegations that the illegal trade in minerals funds conflict in eastern Congo, to the dumping of e-waste on developing countries. (For more about the high-tech life cycle, see Annie Leonard’s animation, The Story of Electronics, and for background on conflict minerals, check out US charity, The Enough Project.)

“Australia is one of the only industrialised countries that doesn’t have effective end-of-life management for electrical goods,” Ms Acaroglu says. “And not only that, we also have no restriction on the hazardous substances used in those goods.”

But at least we’ll soon be able to get old TVs off the footpaths. Under legislation introduced to federal parliament in March, importers and manufacturers will be required to fund and run a national recycling scheme for televisions and computers, set to begin before the end of the year.

Ms Acaroglu says that while the product stewardship legislation is a crucial step, the goods themselves must be made differently. “Many of our products are designed to break. We really need to be creating long-lasting, interchangeable, upgradeable products,” she says.

“We need system service models – so that if you buy a computer, it’s not more expensive to get it repaired or upgraded than it is to buy a new one.”

In the meantime, Ms Acaroglu says householders can still minimise their gadget habit. First, unplug or switch off chargers at the wall – needless energy consumption accounts for a large dose of a mobile’s life cycle impact.

“Secondly, consider the consumption hierarchy,” she says. “Do you really need this product?”

If you really do, consider buying second hand or opting for the best quality, longest-lasting one you can find. Greenpeace’s Guide to Greener Electronics is helpful; it ranks the major brands’ performance on toxic substances, carbon footprint and e-waste.

“Seek out products that have longer warranties or service components associated with them,” Ms Acaroglu suggests. “Cheaper is not always better. And when something is really, truly no longer of use to you, make sure you recycle it.”

You can earn money for your old gizmos on eBay or from buy-back businesses (such as Mazuma Mobile or Cash a Phone), or give them away on Freecycle. There’s also a recycling scheme for mobiles, called Mobile Muster. Victorians can drop off old computers through the Byteback scheme, operated by Sustainability Victoria.

“Don’t leave them stuck in your drawer,” Ms Acaroglu says. “Get those resources back into the recycling stream.”

Read this article at The Age online

Beat urban heat with light surfaces and green spaces

AFTER a hot, still day, parts of the city can be up to seven degrees hotter than the surrounding countryside. Dr Andrew Coutts, from Monash University’s Centre for Water Sensitive Cities, says a phenomenon known as the “urban heat island” effect means that built-up zones are often warmer than rural areas, particularly after dark.

“Urban areas store heat during the day and slowly release it during the night,” he says. “Meanwhile, rural areas can cool rapidly because soil and vegetation don’t store as much warmth.”

The urban heat island effect is present all year round, but it becomes a problem during the hotter months. “Without low temperatures during the night, we don’t get to recover from daily heat stress, especially when we have daytime temperatures in the high 30s and 40s,” Dr Coutts says.

Victoria’s chief health officer found that the heatwave preceding the Black Saturday fires might have contributed to 374 people’s deaths, more than double the number who perished in the fires. “Heat stress is a big concern for vulnerable people, such as the elderly, the really young, and those with pre-existing medical conditions,” he says.

Dr Coutts says the heat island effect has three main causes. Firstly, dense, impervious surfaces, such as asphalt and concrete, trap and store heat from the sun. “In urban areas we have these complex geometries, like street canyons, where heat gets absorbed by the walls, roads and roofs,” he says.

Secondly, human activities, such as driving cars and using air conditioners, generate waste heat. And finally, because cities have fewer trees and less vegetation, they receive natural less cooling from shade and evapotranspiration through foliage.

The effect creates a vicious cycle, in which prolonged heat makes people switch on their air conditioners, which leads to more waste heat. Likewise, higher temperatures predicted under climate change will mean extra air con – thereby increasing both the urban heat island and greenhouse gas emissions.

So how can we sink the heat island?

To keep your property cooler, plant trees in your garden and harvest stormwater for irrigation with tanks and rain gardens. Minimise hard surfaces such as solid concrete; opt for gravel paths or porous paving instead.

Also, lighter colours increase the “albedo”, or reflecting power of a surface, so when you restore or replace your roofing, follow the example of whitewashed Mediterranean cities. “If you paint your roof white, it increases the solar energy reflected away from the surface,” Dr Coutts says.

It’s also possible to buy dark-coloured paints that cut the heat absorbed by your roof. Ceramic-based, heat-reflective coatings are available from a number of businesses, including Astec Paints and Colorbond Steel. “They reflect solar radiation in the near-infrared spectrum,” he explains. “This means you can keep your traditional roof colours, and reduce your energy needs and the urban heat island as well.”

Dr Coutts and his colleagues are studying the cooling effect of street trees, as well as the relative benefits of green roofs and high albedo surfaces. He says the tactics we need for the city-at-large mirror the task at home: we must make our buildings and roads more reflective, plant more vegetation and harvest our stormwater. We also need better public transport to reduce waste heat from cars.

“It’s mainly about smart urban design,” Dr Coutts says. “We can have quite high density living without the impact of urban heat islands.”

Read this article at The Age online