There are still big incentives to retrofit, but be sure to get in quick.

The federal government has once again changed its eco-rebates and programs. Here’s an update on the major schemes.

The ceiling insulation rebate has been scrapped temporarily. It’s scheduled to begin again on June 1. The new minister responsible, Greg Combet, is letting the batts settle before announcing the full details, but the subsidy will be $1000 (down from $1200). Householders will be required to pay upfront and claim the cash later through the Medicare system.

The federal rebate for replacing your old electric hot water service has also been reduced. Householders are now eligible for $1000 for solar hot water systems and $600 for heat pump systems (down from $1600 and $1000, respectively). You can apply for either the insulation or the hot water system rebate, but not both.

The state government offers rebates for solar hot water systems too – up to $1500 in metropolitan Melbourne, and $1600 in regional Victoria – but only if you’re ineligible for the federal incentive. Extra discounts are also available courtesy of the schemes for renewable energy certificates and Victorian energy efficiency certificates.

The federal government has amended the Green Loans program. Previously, householders could receive a free home sustainability assessment and a four-year interest free loan of up to $10,000. The loan component has been axed altogether, but the assessment scheme has been expanded to allow for an extra 600,000 homes. It’s still free and open to renters and landlords, as well as homeowners.

Home sustainability consultant Keith Loveridge, from Eco Assessment, says that despite its administrative hiccups, the program gives householders a great opportunity. “Energy and water bills are expected to increase sharply in the coming years. You can offset those rises right now by identifying areas where you can make savings.”

To get the best advice, he recommends booking assessors who aren’t affiliated with solar panel or water tank retailers. “Try to stay with the independent assessors who don’t try to sell you anything,” he says. “And make sure your home sustainability assessor is accredited. We all carry identification with us.”

If you want solar photovoltaic panels, the federal Solar Credits scheme remains in place. Presently, the rebate fluctuates according to the market value of renewable energy certificates. However, from January 1 next year the price of the certificates will be fixed at $40. According to Nick Brass, from renewable energy retailer Energy Matters, that will translate to a rebate of $5400 for Victorians who install a grid-connected 1.5-kilowatt system.

Owners of photovoltaic panels may also benefit from the state government’s net feed-in tariff, which started last November. It means you can receive cash or a credit on your bill (depending on your electricity retailer) for any excess power you generate. “With a 1.5-kilowatt system, if you feed half the energy generated during the day into the grid you’ll earn about $800 a year. That will allow you to pay off your system in under eight years,” Mr Brass says.

And finally, water. Both the state and federal governments still offer rebates for tanks and greywater systems – all up, you can get $1500 for a tank or $1000 for a greywater system.

All this is just the start of the snail trail. To track the full details, see the Sustainability Victoria and Living Greener websites.

Cohousing combines common sense with green design.

In Melbourne’s north, construction has begun on an urban infill development with a big twist. Ecohousing Heidelberg includes not only 18 eco-designed homes, ranging from one to four bedrooms, but also an extra building with facilities for everyone to share.

Known as cohousing, it’s a type of a residential development where your home is one of about 15 to 30 clustered around a common house and open space. “It’s like returning to the positive aspects of a village or extended family neighbourhood,” says Iain Walker, from Cohousing Australia. “It can be done in urban high-rise, as well as suburban or rural locations.”

The individual dwellings are private and self-contained, not communal, but the residents pool some resources. The common house might include a shared guest room, kitchen, laundry and shed. Outside, there can be shared garden space or play areas.

“It considerably reduces your eco-footprint and the area of land you need, but you can still have quality design and amenity,” Mr Walker says. “And because you’re sharing more community spaces, you often build more affordably.”

The concept originated in Denmark in the 1970s and has become popular in Europe and North America. Mr Walker says that because of the environmental and resource limits facing our cities, it’s crucial we think about different kinds of housing.

There are also important social benefits. “It’s great for young families. You can know your neighbours and support each other with childcare. It’s also great for people to age-in-place for longer. Most cohousing neighbours eat together two or more times per week. Right now the fastest growing household size is single-person, and that isolation and alienation is bad for our health and wellbeing,” he says.

Ecohousing Heidelberg isn’t open to private buyers – it was established by Common Equity Housing Limited, a community housing association. It will offer rental housing for members of a cooperative (applicants must fall under certain income and asset levels).

Andrew Partos is a member of another Melbourne cohousing organisation, Urban Coup. The group, comprised of 30 individuals and families, is looking for land in the city’s inner-north. “We’ve got a diverse mix of people with a breadth of skills and experiences, and a range of ages from newborns to retirees,” he says.

The group has spent over a year gathering members and sorting through issues such as design, legal and financial models, incorporation, articles of association, decision-making and conflict resolution.

The Urban Coup has now reached the toughest stage: buying the property. Spiralling prices and financing delays have stymied other cohousing collectives at this point. But according to Mr Partos, his group has received strong encouragement from within councils and the housing profession. He’s optimistic that Urban Coup can blaze the way for other groups now springing up in the northern and eastern suburbs. “We’re a bit of a prototype,” he says.

Mr Partos works at the state property developer, VicUrban, and travelled to Europe and North America in 2007 to study cohousing projects. He says they typically have eco-footprints about 40 per cent lower than traditional developments.

“You can do things on a larger scale, such as combined blackwater and greywater treatment plants and shared hot water services. And there’s a whole flow on for sustainability, with the opportunity to share vehicles and use bicycles or other types of alternative transport.”

Permaculture helps cut your footprint and grow your food.

When Kat Lavers moved into her Northcote home, she named the property after its big old plum tree. Ever since, she and her housemates have set about transforming the rest of the block into an urban permaculture demonstration site, aiming to show how much of our needs can be met on a small scale.

“The Plummery is less than one tenth of an acre – about 400 square metres – and that’s including the house,” she says. “Once our design is fully in place, we’ll be providing all our salad, eggs, honey, water and electricity, plus a really good supply of our fruit and veggies, and lots of mushrooms. We’ll also process all our organic wastes on site, using technologies like a home-built composting toilet and lots of compost, chooks and worms.”

Ms Lavers didn’t chance upon a suburban oasis. Instead, such abundance comes from careful planning and design based on the principles of permaculture. The word is a contraction of permanent culture or permanent agriculture. “It’s about creating human environments that provide for our needs without requiring massive inputs of resources or producing a lot of waste,” she says. “It’s common sense, but it’s uncommonly applied: designs and behaviours that can exist generation after generation.”

For example, in her house, a greenhouse outside the back door will serve many uses: a space for seed propagation, mushroom growing and hot climate plants, as well as a sunroom for drying laundry and warming the home in winter.

“For me, permaculture is real sustainability – it’s not just changing a light bulb or using a reusable bag,” Ms Lavers says. “I only started learning about it in 2006. I’ve made a big transition in a short time so I feel like it’s possible for many people to do the same.”

Rick Coleman runs Southern Cross Permaculture Institute in Leongatha. He says there’s nothing complex or mysterious about permaculture. “In a nutshell, it’s sustainable design. It’s like playing chess with life, moving the pieces around so they operate best in your system.” That can mean anything from the smart placement of your garden beds to taking advantage of the way soil stores water.

“Every property has some sort of a slope. If you understand where the water flows, you can slow it down, block it or divert it into certain trees so it all stays on the property,” Mr Coleman says.

Good designs link the needs and functions of different parts of the system. “Chickens are the best example,” he says. “They can do all your composting, clean up food scraps, and provide fertiliser and eggs. If you have two garden beds, the chickens can scratch out all the weeds in one, fertilise the area and eat all the bugs. Then it’s ready for planting and you move them into the other one.”

For now, most suburban blocks produce little and consume a lot. Permaculture not only seeks to reverse that, but also establish stronger local networks – it’s the basis for community building movements such as Transition Towns and Permablitz. “You’re going to produce lots of healthy, home-grown food, consume less power and save your dollars. And you’ll also start integrating into the community,” Mr Coleman says.

“You can start simply. Hand a bag of beans to your next door neighbour, and it’s on.”

To find out about permaculture groups in Melbourne, see permaculturemelbourne.org.au, or to learn more about what it’s all about, see permacultureprinciples.com.

Well-placed, high-density materials can keep your home comfortable.

By and large, when house designers mention “thermal mass“, their clients’ minds go blank. The topic seems as impenetrable as a thick bluestone wall.

Sustainable building expert Dr Chris Reardon, of Suntech Design, says it’s a crucial concept for people to grasp – and it’s actually not so complex. “Thermal mass is the battery of passive heating and cooling,” he explains. “It’s where you store free heat from the sun, or free cooling from breezes or radiation to clear night skies.”

Dense building materials, such as concrete, brick, earth or tiles, have high thermal mass – they need a lot of heat energy to warm them up and they retain the heat for a long time. “The main value of thermal mass is to even out day/night temperature ranges. In winter, it stores daytime solar heat and augments night temperatures. In summer, stored night ‘coolth’ can absorb daytime heat gains,” Dr Reardon says. In contrast, lightweight materials heat and cool rapidly.

High-density materials are helpful in climates where there’s a gap of more than six degrees between daytime maximums and night-time minimums. In Melbourne, the temperature often varies by 10 degrees or more. “The more extreme the climate, the more thermal mass you need,” he says.

But mass is just one element of good solar passive design. If not co-ordinated with the orientation, windows, shading and insulation, the heavy materials can accentuate the worst aspects of the climate – the home could absorb extra warmth in summer and stay colder in winter.

“Thermal mass must be exposed on the inside of the house and insulated from the outside,” Dr Reardon explains. For example, the timber and plasterboard internal wall in a brick veneer home insulates the mass in the bricks, meaning they don’t help to curb temperature extremes. The mass is better put to use in reverse brick veneer construction, or by designing internal feature walls of exposed brick, cement-rendered brick or earth.

According to Riccardo Zen, from Zen Architects in North Fitzroy, carefully placed high-density materials are essential to cut energy needs for homes in Victoria. “Our basic goal is to eliminate heating and cooling in our buildings,” he says. “It’s very hard to do that unless you have some form of mass.”

A classic example of thermal mass is an exposed concrete slab floor, positioned in front of windows in a north-facing living room. In the winter, the sun can shine directly on the slab, which absorbs the radiation and warms the house into the night.  With appropriate shading, sunlight won’t hit the concrete in summer and the chill of the slab will help the home stay cool.

You don’t have to start from scratch to improve the thermal mass in your home. Mr Zen says building designers are learning nifty ways to add high-density materials to existing houses, including suspended slabs, aerated concrete blocks and tiles. “We did a project where we brought concrete pavers onto a timber floor using the existing joists,” he says.

“People are also experimenting with using water tanks. Water is one of the best forms of thermal mass – you can also shift it and put it back seasonally when it’s required,” Mr Zen says. “We’re becoming more sophisticated in the way we use mass. There are some hybrid systems evolving to tackle difficult sites.”