Michael Green

Writer and producer

Secondary glazing

In Architecture and building on

Secondary glazing is second best to double glazing, but it’s a cheaper option providing good results

WINDOWS are wonderful for transmitting natural light. The only trouble is they’re also great at transmitting heat. In a typical insulated home, windows cause more heat gain and loss than any other part of the building fabric.

No matter what climate you live in, double glazing can vastly improve the insulation performance of your house. There are a few ways to get double glazing into an existing dwelling: you can remove and replace the whole window frame, replace just the glazing unit, or install dual glazing (an extra glass window on the inside or outside) or “add-on” double glazing (an extra window or pane on the inside).

Unfortunately, all these measures can tear a hole in your hip pocket in the short term (though you’ll save on active heating and cooling costs over the long term).

In this article, Sanctuary takes a closer look at the cheaper end of the scale: dual glazing and “add-on” double-glazing units.

But before you open your chequebook at all, it’s smart to close some other holes around the home. Maurice Beinat, from household efficiency specialist ecoMaster – which produces ecoGlaze “add-on” double glazing – says windows are normally the third priority. “Every home is different, but usually the first port of call is draught proofing. The second one is sufficient ceiling insulation that’s properly installed,” he says. “Then the third stage is a toss up between secondary glazing, window coverings and window shading.”

External shading is crucial to prevent radiant heat transfer through any glass that gets direct sun in summer. Internal window coverings such as heavy drapes and pelmets will help cut down the warmth conducted through the glass. But Beinat says many householders aren’t keen on curtains at all – let alone heavy ones. “If you don’t want window coverings, secondary glazing is a good alternative,” he says.

So what should you look for?

Gary Smith, from the Australian Window Association, says secondary glazing performs two functions – thermal and acoustic insulation.

Some products, known as dual window systems, comprise of a whole new window – with glass and frame – attached to either the inside or outside of the existing window frame. They’re available from many companies – see the AWA website for a list of members in your state.

 “You get some benefit thermally but they’re usually installed for acoustic reasons,” Smith says.

For soundproofing, the air space between the two windows should be at least 100mm; however, for the best insulation results, the gap between the panes should be much smaller.

“In an insulated glass unit you need dry, still air or an inert gas,” Smith says. “The problem with having a big space is that the air moves around inside and it reduces the thermal performance.”

He says the thermal insulation value provided by double glazing increases with gaps of 6mm to about 16mm, and then begins to decline. “When you get up to spaces like 80mm and 100mm, the performance drops off quickly.”

By way of warning, Smith says would-be buyers shouldn’t accept claims about a product’s performance without independent testing under the Window Energy Rating Scheme (WERS). “If you can’t compare it, you’ve got to be careful,” he says.

The other type of secondary glazing system on the market more readily achieves narrower gaps, by using magnets to attach an “add-on” acrylic panel to the existing frame. These systems include Magnetite, MagicSeal and ecoGlaze (by ecoMaster).

Adrian Lafleur, from Magnetite, says high quality seals and materials make all the difference. “You have to make sure you get an air-tight seal. With the frame, PVC or timber will insulate much better than aluminium,” he says.

Products are available that will suit most kinds of windows, and allow them to be openable. Maurice Beinat, from ecoMaster, says acrylic panes work well in retrofitted systems because they’re light, easy to handle and safer than glass.

Cleaning too, is no trouble. “The best way to clean acrylic is with an antistatic solution or a mild detergent and a microfibre cloth,” he says. “Never use ammonia based cleaners, like Windex, because that will make the acrylic go cloudy.”

Acrylic scratches more readily than glass, so beware of combining low windows with pawing pets and toddlers. Mild scratches can be polished out, or the panels easily replaced.

Although secondary glazing systems are much cheaper than replacing the windows altogether, they’re not cheap. Covering your whole home could cost upwards of $10,000, depending on the product you choose.

Clear Comfort is a low cost solution. It’s a kind of plastic wrap stuck onto the frame and shrunk to fit (see case study). For just a few hundred dollars and a little DIY labour, you can double all your windows – but it won’t last as long as the sturdier systems on the market.

Another alternative is to replace just the glazing unit, but this requires a certain level of know-how, and it’s still not keep. You can get started with www.diydoubleglaze.com.au.

CASE STUDY

Two years ago, Adam Tiller applied Clear Comfort to the southern and western windows of his 1928 Federation bungalow, and he’s hooked on the benefits.

“I think it should be compulsory in every house,” he says. “It eliminates the cold draught you feel coming off the bottom of big windows, even when you have heavy drapes.”

The transparent membrane looks “like glad wrap” in the roll, but once installed, it’s hard to see at all. He had no trouble fitting it to both casement and double-hung sash windows, with the help of his partner.

So far, it’s proved surprisingly resilient – though he wouldn’t recommend it where pets scratch or toddlers reach. “My kids poke it and lean on it and it doesn’t come off,” he says.

COST COMPARISONS

A typical window is around two square metres.

Clear Comfort: $198 for a 10 metre by 1.6 metre roll (about $12 per square metre), together with tape and instructions.

ecoGlaze: $300 to $350 per square metre, but more if the windows are oversized, oddly shaped or require scaffolding.

Magnetite: $380 to $420 per square metre.

Article published in Sanctuary Magazine

Recycling in apartments

In Greener Homes on

High-rise doesn’t have to mean high waste.

WHEN Melbourne City Councillor Cathy Oke moved into her CBD apartment, she found there was no recycling collection at all.

“Residential recycling rates in the city are terrible,” she says. “At the last election almost every councillor identified it as an issue that needed to be addressed.”

In the City of Melbourne, the waste diversion rate – the percentage of recycling and green organics collected, as a proportion of total waste – is second worst among Victoria’s municipalities.

Cr Oke puts it down to high-rise dwellings and awkward infrastructure, together with high tenancy turnover rates and language barriers among some residents.

But it’s not just apartments in the city that don’t get it right. In most multi-dwelling blocks, recycling is less convenient than in stand-alone dwellings.

While new apartment buildings are constructed with separate chutes for landfill and recycling, the set-up is more complex in older buildings. Cleaning is expensive, and without dedicated areas and systems, bins become a jumble of rubbish and recyclables.

Even where space and bins are available, well-meaning residents often gather and deposit recyclables in plastic bags, which cannot be recycled by sorting centres. Items must be put loose into the bin, not bundled in plastic bags.

In Cr Oke’s building, recycling bins have been moved off each floor and she uses a special container, supplied by the council, to sort and transport her recyclables.

“It’s like a funky yellow shopping basket that’s easily tip-able. It fits neatly in my small kitchen,” she says. “If you move the recycle bins to reduce contamination, you have to make it easy to go to those locations.”

Christine Byrne, founder of the Green Strata website, suggests residents engage their owners corporation, property manager or building caretaker on the subject.

“To improve recycling rates you’ve got to think about human nature. Don’t fight it. See if you’ve got space somewhere in your building, reorganise it and make it easier for people,” she says.

The best method will vary from building to building. One apartment block, featured on Green Strata, chose to put recycling bins near the lifts on every level. Cleaners empty them every two days.

“Their recycling rate has gone up by making it convenient. It’s where their garbage chute is, so they don’t have to think about it,” Ms Byrne says.

Another key is effective signage. Colour coding and clear instructions can help focus the most absent-minded residents, so ask your local council for education material.

You can also make room for more exotic kinds of re-use. “If you’ve got facilities for recycling, put another container there for e-waste, corks, batteries, printer cartridges  and fluorescent globes,” she says. “Accumulate it and then get a cleaner, caretaker or a willing owner to take it to the appropriate disposal place.”

Some buildings have even begun swapping pre-loved goods. “They’ve created treasure rooms where people can put useable household stuff they no longer want. It’s available for other residents in the building to take,” she says.

Composting is always tricky in apartments, but Ms Byrne suggests putting a Bokashi Bucket or a worm farm (in a shady spot) on your balcony. Owners corporations could buy the equipment in bulk and arrange a workshop to get people started. Alternatively, enthusiastic residents can establish a communal system on shared garden space.

Read this article at The Age online

Wicking beds

In Greener Homes on

Wicking beds make for a water-smart garden.

IN the car space of his Clifton Hill flat, Frank Fisher now grows vegetables. Late last year, together with neighbours and enthusiasts, he fitted two old apple crates as ‘wicking’ beds – a water-efficient system in which the plants quench their thirst from below.

A long-time bike rider and sustainability professor at Swinburne University, Mr Fisher has no need for parking, but he spends much of the week out of town, so he wanted a garden that wouldn’t require constant attention.

Wicking beds can consume as little as half the water of a normal vegie patch. The technique mimics the natural system by which plants access moisture rising up from the water table.

“They’re optimally self-maintaining,” he says. “I’m growing a big selection of vegies, from leafy lettuce to carrots, tomatoes, broccoli and all sorts of herbs.”

Hannah Moloney, from Cultivating Community, says wicking beds can be used in large-scale cropping or backyard pottering. They’re ideal for container gardening in courtyards, balconies or rooftops.

To start, you need to line a container with strong black plastic (or use a water-tight vessel such as an old bathtub with a plug). Place an L-shaped length of piping along the bottom of the container, with holes on the underside and one end protruding for an inlet.

Cover the pipe with gravel, then lay shadecloth or geotextile on top, and add soil or compost (no more than 30 centimetres). Drill a drainage hole level with the shadecloth.

“Invest in the best organic soil you can get,” Ms Moloney advises. “It’s the difference between making or breaking growing in containers.”

Water your new vegie patch by pouring directly into the pipe. If you mulch the soil well, you’ll avoid evaporation altogether.

“The plants draw the water up by capillary action, through the gravel, through the geotextile or shadecloth, and into the roots where it’s most needed,” Ms Moloney says. “Wicking beds are the most water-efficient way you can grow vegetables.

“You can kill plants by not giving them enough water or by drowning them with love – that’s very common amongst urban growers. Wicking beds are really good because you know there’s enough water when it comes out the overflow. You can’t over-water, so it’s a fantastic technique for nervous or forgetful gardeners.”

The technique was pioneered by Queensland engineer Colin Austin during an aid project assisting African farmers to maintain food production under drought conditions.

“He found that the problem often wasn’t permanent drought, but that they had erratic rain – a monsoon or flood and then nothing for six months,” Ms Moloney says.

“He experimented lining small ditches with plastic so the crops’ roots could always access a reservoir. The beds are designed to consistently provide water to vegies, so they have a reliable food source.”

As climate change brings on more extreme weather patterns, the system may prove increasingly important to ensure food security.

For Mr Fisher, the garden has also become an easy way to spend time with neighbours. “We planted the boxes and had a beaut little celebration and BBQ. And there are various residents who are helping with the watering and maintenance,” he says.

“I’ve got the middle flat. Everybody goes past it. All I have to do is get out there and tend to the garden and the passers-by talk to me.”

Read this article on the Age website

Earthships

In Greener Homes on

Zero-carbon housing is one mission of this year’s Sustainable Living Festival.

FOR the cost of a standard house, renegade architect Michael Reynolds builds Earthships: off-the-grid homes constructed in part from waste materials such as tyres, bottles and aluminium cans.

“The designs are always evolving,” he says. “Our latest building is performing really well: it’s maintenance-free and fuel-free, and it’s carbon zero living. But it’s obsolete because we see that we can do it better and cheaper each year.”

Mr Reynolds, who lives in New Mexico, USA, was the subject of the cult 2007 documentary Garbage Warrior. He is a keynote speaker at this year’s Sustainable Living Festival, which began yesterday and continues until February 27.

The Festival’s theme is “Mission: Safe Climate”, and main event at Federation Square runs from the coming Friday to Sunday. There will be nearly 200 exhibitors, events and talks, covering topics from eco-homes to global campaigns.

In his talk next Sunday, ‘The Art of Carbon Zero Living’, Mr Reynolds will detail the lessons he’s learned over the course of 40 years building Earthships. He’s also running workshops at CERES in East Brunswick, as well as Kinglake, Daylesford and the Yarra Valley.

He argues that while many people devote their time to individual aspects of sustainability, the biggest challenge is to combine all the elements.

“There are a lot of people doing great things working with water, power, sewage, heating and cooling, recycling or food. What we’re saying is that the art of zero carbon living is putting all those ingredients together,” he says.

“There are thousands of different ways to deal with those issues. But we have to deal with them in every home and every commercial building.”

Mr Reynolds says it’s possible to take the Earthship approach to retrofitting existing buildings. “If you live in a home that has eight rooms, that’s an energy-hog home,” he says. “Take one room and make it your safe haven – the room you retreat to when it’s super cold.”

He advises choosing a north-facing room, for the best solar exposure, and then thoroughly researching topics such as thermal mass and solar gain.

“Take it step by step. If you try to do your whole house you’re going to have to get a $200,000 loan. But if you take one room you can do it yourself with information you find online. And the next year you do another one, and another one,” he says.

“We’re trying to empower people with knowledge. We’re working hard to make our website a wealth of information that reflects what we’ve learned.”

A key lesson is that reuse is possible on a much grander scale. “So many materials are thrown away in the modern developed world. Every month we’re expanding the materials we can use, and some of them turn out to be better than materials we can buy,” he says.

Mr Reynolds argues that we have no choice but to reassess our approach to housing, given the challenges posed by climate change. Homes must no longer simply be engines of resource consumption and waste production.

“If you’re going on an adventure hike in the Himalayas, you don’t take a grand piano with you,” he says. “Living in the future on this planet is going to be an adventure and travelling light is a big first step on that adventure. But it’s not about doing without.”

Read this article on The Age website

Star ratings on the ground

In Architecture and building, Environment, The Age on

HUNDREDS of thousands of new homes across the country are not performing at their promised energy efficiency rating, forcing residents to use up to double the predicted energy required for heating and cooling, experts say.

Research by air-tightness testing company Air Barrier Technologies has shown that air leakage in new homes is five to 10 times worse than expected under the star-rating scheme.

This means that an average five-star home is likely to perform only to a three-star level, potentially doubling energy bills for residents.

About 40,000 new homes are built in Victoria each year, and all must adhere to the five-star standard. This will rise to six stars from May.

But a group of industry players, including Henley Homes, who have been lobbying state and federal government and building regulators to crack down on the air leakage problem, say unless more action is taken, customers cannot be confident their homes meet the stated star rating.

“At the moment there’s an assumption that houses are built to a far tighter standard than what we believe they are in reality,” Adam Selvay, Henley Homes energy and sustainability specialist, told The Sunday Age last week.

The question of builder liability was raised in a meeting with the Federal Department of Climate Change and Energy Efficiency and the Australian Building Codes Board in April last year.

Following that meeting, Terry Mahoney, president of the Air Infiltration and Ventilation Association of Australia, emailed other attendees, as well as federal government ministers and senior public servants, criticising officials for failing to respond to the issues discussed.

“It became apparent that no amount of scientific evidence, or global best practice comparisons or safety and health risk concerns raised by the visiting group, would engender any action or urgency from either the [Department of Climate Change and Energy Efficiency] or the [Australian Building Codes Board] at this time,” he wrote.

Mr Mahoney noted the attendees’ view that there is “overwhelming evidence” that the current star rating method “proves grossly inaccurate when constructed homes are performance tested”.

Bruce Rowse, from building efficiency consultants CarbonetiX, said air gaps are common around doors, light fixtures, window- and door-frames, and places where pipes or cables enter the home.

“Sealing is very important and to do it properly is really laborious. And there’s no inspection for it,” he said.

He also expressed concern that the regulatory regime doesn’t ensure insulation is adequately installed. “The building inspector has no idea of what insulation actually goes into the walls,” he said. “It’s also very difficult to validate exactly how well the ceiling is insulated.”

Victorian Building Commissioner Tony Arnel denied there was a systemic problem with air leakage standards or insulation in five-star homes. He maintained that an auditing process had consistently demonstrated that new homes complied with regulations.

“But building is not necessarily always a perfect science. We did some research two years ago with Air Barrier Technologies and that did tell us that there was potentially an issue with draughts and gaps that we needed to continue to work with industry to ensure that quality is met,” he said.

Mr Arnel said if testing proved a home did not meet its star rating due to building deficiencies, the owner could take legal action against the builder “because presumably it hasn’t been built to the right specification”.

Housing Industry Association building and environment director Kristin Brookfield said the association was not aware of any specific research on air leakage but acknowledged that a building’s energy efficiency is affected if it is not properly sealed.

“It’s important that this is seen as an issue about the rating tools,” she said. “This is not an issue about the actual construction of the homes.”

Lin Enright, from the Australian Competition and Consumer Commission, said that concerns had been raised with the Department of Climate Change about air infiltration, but no complaints or inquiries had been brought to the attention of the consumer watchdog.

The issue was privately championed last year by former Victorian Planning Minister, Justin Madden. In July, he wrote to the federal Minister for Innovation, Industry, Science and Research, Senator Kim Carr, requesting that the Australian Building Codes Board consider testing for air leakage to ensure greater energy efficiency of housing and other properties.

Read this article at The Age online