Insulation works all around the house.

CEILING insulation is taking a lot of political heat this year. But while the federal government admits its rebate scheme was flawed, the insulation itself shouldn’t be left in the cold.

Caitlin McGee, from the Institute for Sustainable Futures at the University of Technology, Sydney, says good insulation is always a crucial part of construction. “It has many benefits: greenhouse gas reduction, better comfort and lower energy bills.”

And the ceiling isn’t the only spot for it. “The roof cavity is the most important place, but if you want to insulate well, you need to think about the walls and floors, and the building shell as a whole,” she says.

If you’re building your house, get the wall insulation right first time – it can be difficult and expensive to add later. According to Ms McGee, in existing homes, the best opportunity to retrofit is “when you’re renovating or pulling apart your walls for some other reason.” In all cases, it’s wise to consult a building sustainability assessor for detailed advice.

Because heat transfers in different ways, a combination of both reflective (foil) and bulk insulation (such as batts) works best. When you’re choosing a product, consider its green credentials, such as recycled content, as well as its performance, measured by the R-value.

In Melbourne, the building code requires that walls rate a minimum of R2.2. “Generally, the more extreme the climate, the more insulation you should have,” Ms McGee says. But she warns DIYers not to buy overly fat batts that must be squashed to fit. Bulk insulation works by trapping air; it’s less effective when compressed.

Another retrofitting alternative is to add the insulation outside. On her home, Ms McGee affixed polystyrene and cement panels to the external walls. “The material I used as my cladding is also part of my insulation strategy,” she says. “It’s worthwhile thinking about less conventional materials that have good insulating properties.”

Underfloor insulation is more straightforward, so long as there’s enough access space. Maurice Beinat, from home retrofitting business ecoMaster, says you need about 400 millimetres to work in.

Although floors cause less heat loss than ceilings and walls, insulating them can make a big difference to winter comfort. “The special thing about floors, particularly polished timber, is the contact your feet make with them,” he says. “Floors don’t need to be very cold to make you uncomfortable.”

He suggests that well-insulated floors should reach R2.5. (Uninsulated timber floors rate R0.7, and with good-quality carpet and underlay, they rate R1.)

Mr Beinat says there are two requirements for floor insulation: that it doesn’t hold moisture and won’t become a rat nest. For those reasons, he recommends polyester insulation (manufactured in a roll, rather than a batt, for convenience). Before stapling it in place, seal any gaps in the flooring.

In homes that have a lot of underfloor airflow, such as weatherboards, ecoMaster also fastens a layer of reflective insulation to the joists, making the sub-floor nearly air tight. They charge between $28 and $35 per metre, installed.

Mr Beinat says it’s a job well suited to DIYers, but with one serious warning: “The main danger is electrocution by stapling through wires. People do die underfloor.” He advises purchasing a double-insulated, electric stapler, rather than cheaper handheld models that won’t protect against electrocution.

On the first Sunday of every month, the members of Dig In Community Garden hold a working bee. “We make compost and we tidy the place up,” says Ann Rocheford. “Then we retire to the barbeque and open the red wine – it’s good community-building time.”

The Port Melbourne garden, in Murphy Reserve, has been running since 2003. There are 51 plots and well over a hundred people who regularly stop in. The members reflect the mix of the suburb, from old-timers to newly arrived apartment dwellers. “In the garden they all speak a common language: it’s about how their crops are going. That helps people get to know each other,” Ms Rocheford says.

The plots range in size from four to ten square metres. “It’s amazing how much you can grow on a small amount of land if you look after it properly,” she says. On her plot, she grows “more than enough” for her and her husband. She has finished her winter planting and although it’s a slower time of year, she still tends her patch at least once a week: watering, harvesting and tormenting white cabbage moths.

“You have to be there regularly. It’s a constant thing – community gardens have a ‘use it or lose it’ policy. In summer, you’ve got to be able to water your plants three times a week.”

But the returns on that commitment are many. As well as reinforcing your sense of community, regular trips to the garden are good for your health. “Bending your back and doing some work is very beneficial – if you really want a good workout, try making compost,” Ms Rocheford says. “Also, the vegetables are organic. You pick them, put them in the pot that night and eat them. It’s terribly healthy.”

Ben Neil is the president of the Australian City Farms and Community Gardens Network. He argues that these gardens are a crucial part of the bigger push towards sustainable living. “If we are to face the challenges of climate change, then urban agriculture and community gardens have got to be part of the solution.

“They tick so many boxes: they give you an opportunity to meet your neighbours, improve your mental and physical health, and grow and eat locally produced, organic, fresh fruit and vegetables.”

Melbourne’s oldest community garden, in Nunawading, has been running for over three decades. At last count, in 2006, there were 75 gardens across the city. They’re sprouting. “There’s tremendous demand for new gardens,” Mr Neil says. “A lot of councils now are developing policy to deal with the requests.”

The start-up process is never quick and easy – establishing a group, finding land and gaining council permission is more likely to take years than months. (The South Australian neighbourhood house association, CANH, has released a comprehensive how-to guide.)

One thorny objection is that starting a community garden means privatising open land. Mr Neil says groups can keep the wider public involved by running regular tours, workshops or growing fruit trees anyone can harvest.

“But the reality is that land is going to become harder to find,” he says. “The natural progression is the sharing of backyards. Many people have more space than they need and are happy for others to use it.”

 

 

Modular houses can be green, if you choose carefully.

For most buyers, prefabricated homes have three big pluses: a set product, a set price, and construction in double-quick time.

The factory-built process can also result in far less waste. Architect and environmental design consultant Chris Barnett, from Third Skin Sustainability, says that even if prefab companies aren’t eco-minded, they’re likely to use materials efficiently.

“Supply chains can be refined and controlled to reduce waste – there’s an alignment between waste saving and cost saving,” he says. “Also, the site impacts, noise and ecological disturbances will all be cut down if the on-site construction time is short.”

But it’s a mistake to assume that modular always means green. Most modular houses use steel framing, which has much higher embodied energy than timber. Another potential disadvantage of prefab is the lack of thermal mass, meaning the homes can’t store the heat from winter sun or the cool from summer nights. Quality modular buildings compensate by adding extra insulation so they require little energy to stay comfortable.

Homebuyers need to assess a modular dwelling’s design and performance just as they would conventional on-site builders and plans. “Look at the building fabric and the star rating, as well as the energy and other environmental impacts of delivery,” he says. “If it’s a green modular house, it should have a high star rating and low energy demand through smarter appliances and lighting.”

Mr Barnett is developing SmartSkin, an innovative manufactured housing system that uses timber wall panels that are both structural and insulating, and a factory-built technology pod. He expects to complete the first home by the end of the year.

“We’ve been building the same way for hundreds of years – we still get handed the same piles of sticks and nails,” he says. “Over the next 20 years we are going to see significant changes. The efficiency of manufactured and component-based construction will be crucial in creating greener housing that remains affordable.

“There aren’t many sustainable options on the market now, but products are starting to come from overseas and Australian manufacturers are beginning to gear up.”

One Australian manufacturer taking sustainability seriously is Eco Villages Worldwide, based in Bendigo. They sell Eco Pods – flat pack homes that are assembled on-site in three weeks. “When someone buys one, I make an order and it creates a list of every product needed,” says Bryce Tonkin. “It’s a manufacturing process for the building and that has massive ramifications for efficiency, and reducing waste, time and effort.”

Mr Tonkin says the market for prefab homes has grown over the last few years. “More and more, people want buildings quickly. Our path has been to design those homes for their eco-friendliness and energy efficiency.”

Eco Pods are rated at 7.5 stars, which means they need about two-thirds less energy than standard five-star homes. Among the carefully selected materials are compressed-straw wall panels made locally in Bendigo, recycled carpets and decking made of old milk bottles and sawdust. The three-bedroom design sells for $230,000.

“There are a lot of people who want to reduce their carbon footprint and ongoing energy costs, but it’s complicated if you’re starting from scratch,” Mr Tonkin says. “We’re trying to make it easy for people to get something they can move into now.”

Home buyers benefit from reading the eco-scorecard.

Household energy efficiency ratings (or star ratings) tell you how comfy the temperature of your home will be throughout the year.

“Most people wouldn’t know the star rating of their house,” says Matt Fisher, from the Association of Building Sustainability Assessors. “But the stars have a dollar value in terms of the price and running cost of the home – that will become better understood as a lot more houses advertise with their star rating.”

So how are the ratings figured out?

Energy assessors plug the details of your plans (or existing building) into a nationally accredited software program, such as FirstRate5 or AccuRate. The program analyses the home’s layout and orientation, and the construction of the roof, floor, walls and windows.

This information is matched with the local climate to calculate how much heating and cooling you’ll need. “It’s a very sophisticated model,” Mr Fisher says. “Using climate data collected over many years, it calculates [the home’s temperature] for every hour of every day of the year. It works out the amount of heat or cooling energy necessary to keep the house comfortable.”

Homes can score between zero and 10 stars. At zero stars, the building does next to nothing to protect against temperature outside; at 10, it will be comfortable all year round without artificial heating or cooling. A five-star home is good, but far from outstanding.

Last year, state and federal governments agreed to lift the residential standard from five to six stars. The states must bring the rules into effect by May 2011, at the latest.

“It’s a step in the right direction, but we need to go further,” says Liz Minchin, Age journalist and author of new eco-book Screw Light Bulbs. She argues the regulations should have been more ambitious, by adding a timetable for even higher standards and factoring house sizes into the ratings.

“The five-star regulations helped slow down the increase in emissions from Victorian homes, but those emissions are still growing – largely because houses are getting so much bigger,” she says.

“Bigger homes typically take more energy to keep cool or warm – and that costs everyone money in rising energy bills, because we need to build more expensive power generation to cope with spikes in electricity use.”

The good news is that the governments have agreed to another change that should push household energy efficiency higher. Homeowners and landlords will soon be required to declare the energy, water and greenhouse performance of a house when they put it up for sale or lease.

It means that buyers and renters will be able to compare the environmental impacts and ongoing costs of different homes. Even though the full details and start date aren’t set (it will be phased in from May next year) the plan is relevant immediately – especially for people considering renovations.

Ms Minchin says a similar mandatory disclosure scheme in the ACT has shown that energy-efficient homes attract higher prices. A study for the federal government found that in 2005, lifting the energy rating of a median-priced house in the ACT by just half a star added about $4,500 to its value.

“Buyers are becoming more conscious of climate change and energy prices,” Ms Minchin says. “Real estate agents say people are asking about energy ratings more and more.”

Compost toilets save water, energy and nutrients.

We flush nearly one quarter of our household water down the toilet. “At the moment there’s this silly situation where we use high-grade water to flush our toilets,” says planning expert Professor Patrick Troy from the Australian National University. “To cut down our consumption of potable water, we need to change the way we manage human body wastes.”

Professor Troy, editor of Troubled Waters: Confronting the Water Crisis in Australia’s Cities, says composting toilets work with little or no water, and are suitable for suburban and even multi-storey housing. “They can be fitted into standard bathrooms so they look just the same, except they don’t have cisterns and flushes.”

The many different designs – both commercial and owner-built – fit into two broad categories: continuous or batch composting. Continuous systems, such as the Clivus Multrum, use one container. The material decomposes slowly and emerges as finished compost that can be safely dug into your garden. Batch systems, such as Rota-Loo, use two or more containers. Once one is full, it is replaced, sealed and set aside to compost. Commercial systems cost from $800 to $8000, depending on the model and size.

The Environmental Protection Authority accredits commercial composting toilets before they can go on sale. The authority’s code of practice for onsite waste management permits them to be used in both sewered and unsewered areas.

Hamish Skermer runs Natural Event, a business that provides composting toilets for festivals and events around the world. “People can have confidence that these systems meet rigorous standards,” he says. “Composting toilet technology can work anywhere on any scale. If we can do it for 18,000 people at the Falls Festivals, then a family of five can do it in their home.”

Even so, householders often find it difficult to get council approval, usually based on perceptions rather than substantive health issues. But those attitudes are changing: Natural Event has already provided toilets for community events run by a number of Melbourne councils.

Unlike conventional toilets, compost toilets require some maintenance – at the least, to distribute the finished soil conditioner. “They all have to be managed, because it’s not a flush system where it’s taken away and it’s someone else’s problem,” Mr Skermer says. The toilet should not smell. If it does, it’s a sign that something isn’t right. But he says that householders can easily fix any issues by attending to the drainage or ventilation, or adding cover material such as sawdust.

He argues that pee and poo shouldn’t be even referred to as waste. It’s the line of thought most recently popularised in The Humanure Handbook, by American writer, Joseph Jenkins. “We have to understand that shit ain’t shit,” Mr Skermer says. “Waste does not exist in nature. The mere concept of a toilet being ‘waste management’ is a backwards thought.”

Compost toilets not only dramatically reduce water consumption, but also cut the energy required to pump sewerage (currently powered by heavy-polluting brown coal) and return valuable nutrients to the soil. “Our food contains nutrients in the form of nitrogen, potassium, phosphorous and all the trace elements,” Mr Skermer says. “We eat and then pee and crap into the sewer system and a large amount of these nutrients are pumped into the ocean. We’re removing ourselves from the cycle.”