Meet the eco-housing standard that demands attention to detail.

HOUSEHOLD energy use accounts for nearly one-fifth of the Victoria’s greenhouse gas emissions. And while our residential efficiency standard will rise to six stars next year, we’re still lagging behind many parts of the US and Europe.

If you want your home to stand above the rest, you could take your cues from one of the most rigorous standards of all: passive house.

Founded in Germany and Sweden in the 1990s, passivhaus (in the original German) is a voluntary standard for building energy efficiency. It aims to create homes that don’t need any conventional heating – even in the bitterly cold winters of northern Europe.

Christoph Begert, from eco-consultancy Sustainable Built Environments, has studied the way passive house principles apply to Australian homes. He’s speaking this week at RMIT’s Green Building and Design Conference.

The concepts involved are nothing new: they include all the usual suspects of passive solar design, such as good orientation and shading. But they’re combined without compromise. “The rigor of the requirements is what makes passive houses successful,” he says. “They effectively decouple the internal climate from the external climate.”

Mr Begert, originally from Germany, says the criteria are such that the power of a hair dryer is sufficient to heat a 100-square-metre home. “The houses often end up not requiring any heating system at all, because a few people and electrical appliances produce more heat than a hair dryer does.”

There are three crucial elements of a passive house. Firstly, the homes are ‘super-insulated’ to two or three times the level required here. Windows are usually triple glazed.

Secondly, they’re sealed like a snap-lock bag. Gaps and cracks must be comprehensively stopped, to the point where the air change rate is less than 0.6 of the volume of the house per hour. That’s up to 30 times less than the rate in a typical Victorian home when a strong wind is blowing.

Finally, to make sure there’s plenty of fresh air inside, passive houses have mechanical ventilation systems. They often use a heat exchanger, which captures the heat from exhaust air to keep the temperature constant inside.

The result, according to Mr Begert, are homes that rate beyond nine stars.

He has examined the performance of passive houses in Spain and Italy and compared them to conditions here. “From our analysis, we found that Melbourne has a very good climate for passive houses,” he says.

Because of our warmer climate, the insulation need not be so extreme and windows only double-glazed. Good shading is compulsory to avoid baking in the hotter months. “Passive houses perform extremely well during winter, but you have to be sure you don’t make an oven during summer,” he says.

In Europe, homeowners have found that building a passive house costs between 10 and 15 per cent more than a standard home. But with little or no heating and cooling, ongoing expenses are low.

The theme of the RMIT conference is “Greening the Existing Building Stock”. Mr Begert argues that the passive house principles can be applied to renovations as well as new homes.

“You don’t renovate your house very often. When you go to that effort, it’s worthwhile getting it right. You’ll spend a bit more money, but you get really good value for it.”

The early gardener attracts the worms.

IF you want to rest easy with a comfy crop of home-grown vegies this summer, now’s the time to make your beds.

Helen Tuton, from Sustainable Gardening Australia, recommends backyard farmers pamper their soil. “Soil is just so important,” she says. “It’s the medium that feeds plants and gives them all the nutrients they need. Vegie patches are really hungry, because annual crops are very nutrient intensive.”

The first step is to clear the patch. Ms Tuton warns that we mustn’t be sentimental about our flagging winter crops. “People are always reluctant to pull them out, but you need to get ruthless,” she says.

Then, to prepare the soil for planting, aerate it lightly with a garden fork, add a layer of good organic compost and chook-poo fertiliser pellets, and mulch to a depth of about six centimetres. “If you don’t mulch, your compost and soil dries out and loses a bit of its vigour and vitality,” she says.

Water occasionally, but otherwise, leave the bed alone for a few weeks. “By the time you come to plant in September or October, it’ll be rich and full of worms,” Ms Tuton says. “If you’ve got good soil management practices in your vegie patch, 95 per cent of the hard work is done.”

Typically, Australian topsoils are shallow, clayey and ill-equipped for fast-growing annual crops. That means if you’re growing vegies, you can never add too much organic matter.

But to get the best results, it’s also worth taking a close look at the chemistry of your backyard, according to Adam Grubb from Very Edible Gardens (VEG).

“When you get the balance of the minerals in your soil right, your soil structure improves, your plants get a lot healthier and the food that you eat is more nutritionally dense,” he says.

VEG offers soil tests and interpretive reports with a focus on organic solutions, from $160.

Mr Grubb says there are three main soil types in suburban Melbourne (they change again when you reach the Dandenongs).

The eastern suburbs lie on ancient ground, grey-yellow clays dating from the Silurian period about 440 million years ago. “They tend to be leached, nutrient poor and have really bad structure,” he says.

All the soils he’s tested in the region have been lacking in calcium, boron and manganese – deficiencies remedied by adding lime (not dolomite), basalt rock dust and micro-nutrients.

The second area, south of the Monash Freeway and towards Frankston, has sandy soils that dry out quickly. For vegie gardens there, Mr Grubb prescribes regular applications of organic matter and mulch.

The third area, he says, is the volcanic plains that start in Northcote and go west, almost to South Australia. They’re the third-largest volcanic plains in the world.

“Volcanic soils are rich and much more nutritious. But the ones we have here are heavy clays, so you need to work in organic matter and calcium, like gypsum or lime.”

City soils can also sometimes bear pollutants, such as lead. “Where you’re near a major road or you’ve had flaking paint, there’s a potential for lead contamination,” Mr Grubb says.

Again, it’s always prudent to add organic matter, because well-composted soil reduces the lead uptake in plants. “There are some days I think compost can fix anything outside the marital bed,” he says.

Existing structures can become affordable, eco-friendly homes.

FOR people searching for low-cost housing, there’s one modern pursuit akin to alchemy: transforming steel shipping containers into homes.

There are over seventeen million containers around the world, many of which languish in ports with nothing to do but rust, while yet more are fabricated and sent to sea.

“China is the major exporting nation in the world,” says architect Matthew Grace. “The containers sit at wharves because it’s not economically viable to send them back empty.”

Overseas, the crates have been successfully stacked into student housing and temporary accommodation. There have been eye-catching projects in London, including the Container City apartments and a 120-room Travelodge hotel.

To date, few similar developments have landed in Australia, but Mr Grace’s resPOD designs might change that. The dwellings, which comprise up to four containers, cost between about $30,000 and $185,000, fitted out. He has set up a factory in Benalla, and the first orders for family homes will soon be delivered to Hurstbridge and Wandin North.

“It’s not about living in a shipping container, but rather, using the steel structure of the container in lieu of a standard timber frame,” Mr Grace says. “It’s a sustainable kind of architecture, and it’s cheaper to build.”

If you’re trawling for crate ideas, try the Fabprefab website. It has a page devoted to container housing projects, together with links to technical resources and books.

However, bear in mind that a recycled building frame alone doesn’t equate to a sustainable home. To set sail for the highest possible star rating, the dwelling must also be well oriented and insulated.

And shipping containers aren’t the only structures waiting to be re-enrolled. When Abbie Heathcote travelled to Melbourne from her home in Castlemaine, she always noticed a playground of disused portable classrooms by the freeway.

“I wanted to build something fairly quickly and I didn’t have a lot of money,” she says. “I like recycling and I’d often thought it was a shame to waste those classrooms.”

So Ms Heathcote, an artist and writer, bought one for $3000 and spent just 13 weeks converting it into a home, with the help of a builder. (See a detailed article about her home in ReNew magazine, Issue 112.)

“The classroom has solid metal bearers and the roof and external cladding were fine. But the floor wasn’t structurally sound so we had to put joists on top of it and install a new one,” she says.

They insulated the floor, walls and ceiling and added internal walls. Ms Heathcote hunted down fittings and furnishings at garage sales, and cut costs by doing much of the work herself. “I did all the light labour: tiling, plastering, floor finishing and fiddle-diddling around,” she says.

She oriented the dwelling to the sun, and removed one of the windows to the south. “I can’t bear to live in houses without windows to the north,” she says. “During the day the slightest bit of sun warms the whole place up.”

The old schoolroom now comprises two bedrooms, a kitchen, a living and dining area and a bathroom and laundry. Ms Heathcote also constructed a broad verandah and enclosed an extra room – making it about 80 square metres in total.

Altogether, the project has cost just over $50,000. “My friends have been amazed at how attractive it is,” she says. “It’s extremely pleasant and comfortable to live in.”

A new housing development will have residents eating the suburbs.

OUR public spaces need not only be ornamental, according to Andrew Partos from state property developer VicUrban. “Streets can be productive as well as aesthetic, and fruit trees are often very beautiful to grow,” he says

In its Meridian housing development in Dandenong, VicUrban is putting nutrition into the nature strip. The streets will be lined with a mix of about 20 kinds of productive trees, including apricots, apples, pears, figs, mulberries, lemons, olives and hazelnuts.

“There are also urban orchards in the public open space, and an area set aside for community gardens,” Mr Partos says. The first two stages of the development have sold out and the third is scheduled for release later this year.

A residents’ association will manage and harvest the trees, together with interested local groups and schools, if necessary. The approach was modelled on similar schemes in Europe and North America.

Here, many councils have long been opposed to public fruit trees, for fear of maintenance bills or litigation should something go wrong. “Those arguments can be addressed,” Mr Partos says. “Some areas of California have had productive landscapes in their streets for a long time, with community organisations set up to manage and run them.”

As well as the edible trees, Meridian includes liveable street design, where slow moving cars must share the paths with pedestrians. The stormwater runoff flows into green landscaped edges, where it waters the plants directly.

Unfortunately, there’ll be a delay before the trees bear fruit, because the first planting was damaged during the construction process.

It will be worth the wait. “Productive landscapes deal with a number of sustainability issues. If you can provide locally sourced fruit you remove a lot of the oil used in fertilising, harvesting, transporting and purchasing it,” Mr Partos says. “But we’ve found that the even greater benefit of all this is the creation of strong neighbourhoods and communities.”

Kirsten Larsen, from the Victorian Eco-Innovation Lab at the University of Melbourne, says it’s crucial we understand that food is a major part of our household footprint.

“When we talk about reducing environmental impact, we often don’t include food. But it is our biggest source of water use, half our waste to landfill, and nearly 30 per cent of our household greenhouse gas emissions.”

She says the planning model for urban areas must change. “We suck resources into our cities, use some of them and waste a whole lot. We need to think about our cities as productive, as well as consumptive spaces. We have the resources here that we need: water, nutrients, space and sunlight.

“Growing some of our food helps close energy, water and nutrient cycles. It cuts the need for transport, encourages healthy eating, and can create green spaces, cooler urban areas and jobs.”

The Eco-Innovation Lab developed an online ‘food map’ detailing locations of food production across the city. Ms Larsen says interest in city food growing has been “exploding”, with guerrilla gardeners, backyard produce swaps, and people grafting fruiting varieties onto existing ornamental trees.

In that spirit, Yarra Urban Harvest is about to plant a community orchard on private land in Collingwood. The group also encourages people to plant productive trees on nature strips and traffic islands – especially in Yarra, where the council hasn’t been removing public gardens set up by residents.

There’s a big upside to removing halogen downlights.

THE federal government has banned the sale of most incandescent light globes, but one kind is still available: halogen downlights. Unfortunately, they’re still marching two-by-two throughout the nation’s homes.

“As light sources, halogens make really good heaters,” says Lance Turner, from sustainable technology magazine, ReNew. “Like all incandescent globes, they’re really inefficient. Less than ten per cent of the power they use turns into light. The rest is turned into heat.”

That excess heat poses a significant fire risk when debris or insulation strays too close. It’s one of the problems that caused the demise of the federal government’s insulation rebate.

But while shonky installation jobs have rightly been condemned, the real problem lies with the halogens themselves. Not only do they run hot and gobble too much electricity, but the necessary gaps in insulation also fatten our heating and cooling bills. “They can cost hundreds of dollars a year to run and they don’t even light rooms very well,” Mr Turner says.

When Cameron Munro and his wife Karin moved into their house in Malvern, the ceiling was spotted with 23 halogen downlights; their insulation “looked like a Swiss cheese”.

In the process of retrofitting the home, they removed nearly all of them. In the lounge room they replaced five halogens with a single compact fluoro bulb, slashing the electricity demand from 250 to 15 watts. “We only kept downlights where they were appropriate – for task lighting over the kitchen sink and in the reading area,” Mr Munro says.

In those spots, they switched the halogen bulbs with LEDs. They placed protective covers over the fittings in the ceiling and filled up the insulation cheese holes.

“With the covers we can run the insulation much closer and effectively eliminate the fire risk,” he says. Downlight protectors, such as the Tenmat or Isolite, are available at hardware stores for less than $20.

According to Mr Turner, the best light fittings are those for which you don’t need to punch a big hole in the ceiling. He argues there are many better options, from classic pendant or oyster fittings, to new products such as disc-style puck lights or strips of LED lighting that can be hidden along pelmets.

If you want downlights, there are a few ways to replace halogen bulbs. Low-energy ‘infra-red’ halogens are cheap and easy, but don’t make much difference. “The low-energy halogen replacement for a 50 watt bulb is still 35 watts,” Mr Turner says.

You can also directly exchange them with LED downlight bulbs, but Mr Turner argues that without appropriate fittings, they bulbs are unlikely to last their full lifespan. To replace fittings you’ll need an electrician, but it’s a quick job.

For a recent ReNew case study, Mr Turner opted for Crompton CFL downlight fittings (Edison screw, about $10 each) with LED bulbs purchased online from the US (US$25 to $50).

“Generally the ones available in Australia are more expensive because they’re not sold in large quantities,” he says, noting that it’s important to assess the quality and standards compliance of overseas products. For a local supplier of complete fittings, he suggests Brightgreen.

Although the cost of fittings and LEDs varies widely, the expense is worthwhile. “If you upgrade to an energy efficient fitting the payback period is never longer than about five years.”