Sanctuary: Modern green homes

Green by nature

This is an excerpt from an article in Sanctuary magazine issue 17.

In a place not known for its modest homes, a specialist landscaper is doing all he can to restore and rejuvenate the bush while creating a series of “treehouses” for his family.

Words Rachael Bernstone
Photography Simon Whitbread

When Mark Paul and his wife bought an old house on a large block in Palm Beach – holiday playground of Sydney’s rich and famous – they planned to use it as a weekender and eventually retire there. That was 14 years ago, and the couple have since had two children, now aged eight and 10. When the kids were younger, the Pauls found it was too much effort to decamp for the weekend, but now they are older the family is once again frequenting the northern beaches.

Mark trained and worked as a marine biologist before becoming a successful sailboard designer and maker. Towards the end of his sailboarding days he began exploring his passion for landscape design, particularly the creation of green walls and green roofs. His business The Greenwall Company, founded in 1997, is well known for its innovative no-soil planting of vertical and roof surfaces, which helps to extend the natural world within the built environment.

Mark was keen to apply those same principles to the Palm Beach property, a nearly-2000 square metre block with a 46 metre drop from its highest point to street level. “I was very keen to keep the tree canopy and improve on that by removing weeds and exotic trees from the site – which I replaced with indigenous species,” he says. “Because of the steep incline, the site needs to be kept well vegetated [to reduce erosion].”

If you’d like to read the rest of this article you can buy this issue here.

Red brick renewed

This is an excerpt from an article in Sanctuary magazine issue 18.

A modest extension means this suburban Adelaide house works more naturally to keep its occupants comfortable, and has also inspired them to live more sustainably.

Words Sasha Shtargot
Photography Craig Parham

Kirsten Aberle and David Mason always knew they would renovate the 1920s red brick bungalow they bought in 2004. Starting a family would make it necessary to extend the four room house in the Adelaide suburb of Hawthorn – when daughter Elizabeth was born three years later, it was time to act.

“We originally just wanted a house that had lots of light in winter and was cool in summer,” Kirsten explains. The couple were interested in sustainability and called Archicentre for an architect with green credentials. They were rapt with the initial renovation proposal by Emilis Prelgauskas and hired him as the designer and Energy Aspect Living as the builders.

The renovation started in late 2008 and took about six months, the family living in the house for most of the time the extension was being built. “We really enjoyed living in the house during the renovation,” Kirsten says. “We were able to ask questions on a daily basis if something was being done that we didn’t understand, and this was invaluable in decreasing ‘mishaps’ or miscommunications.”

If you’d like to read the rest of this article you can buy the issue here.

Windows that work

From Sanctuary issue 10. More articles like this

By Michael Green

Excerpt: Windows might be transparent, but they’re complex. Good windows well placed will help keep your home comfortable all year round. Bad windows in the wrong places will cost your dearly.

In a typical insulated house, windows cause more heat gain or loss than any other part of the building fabric. While they’re expensive up front, they’re also an investment in the resale value and day-to-day comfort of your home.

So which windows should you choose? There are hundreds of products and combinations to consider, from the glazing, frames and coatings, to the size, shape and location. The Window Energy Rating Scheme website (www.wers.net) lists detailed ratings of over 40,000 products.

Two years ago, Alan Kerlin designed his sustainable home in Canberra. Afterwards, he established a consultancy, Solar Flair, to help pass on what he found out. When he was researching windows, he found good advice hard to come by. “It’s a difficult area, but it’s easier if you understand some of the basics behind the science,” he says.

Heat transfers in different ways – for windows, you’ll need to consider “conduction” and “radiation”. Conduction refers to the ambient warmth that passes through the glass and the frame. A window’s conduction is measured by its U-value. The lower the U-value, the better its insulating qualities, and the better for your energy bills.

Radiation, in contrast, refers to heat transferred when sunlight passes through the glass, hits something and warms it up. Light is converted into heat as the visible light is absorbed by a thermal body and re-emitted as long-wave or infrared energy – heat.

Radiation is measured by the window’s Solar Heat Gain Coefficient (SHGC); the higher the SHGC, the more radiant heat it lets through.

Passive solar design
Armed with this knowledge, you need to consider the weather where you live and the design of your home. Most Australians live in climates where we want to draw in extra warmth during the cold months and shut it out throughout the hot months. With careful consideration, your windows can help this happen – together with other elements of passive solar design, such as shading and orientation.

In Canberra, Kerlin designed his home with a bank of glass to the north – the sun streams in throughout winter, but eaves and shading block the direct rays in summer. Small windows to the south, east and west help reduce the solar access when the sun is low in the sky and passes below the awnings. “But remember: it all depends on where you are living,” he says. “In northern Australia, you don’t want sun hitting your glass at all.”

Insulating glazing units (IGUs)
No matter your location, there is one constant: double glazing is always preferable to single. For now, nearly every Australian home has single-glazed windows. “They’re like a thermal wound in the building envelope,” says Gary Smith, from the Australian Window Association.

Double and triple glazed windows – known as IGUs (insulating glazing units) – help seal the wound. “Standard double glazing can reduce conducted heat transfer by about half,” Smith says. Triple glazing is common in Europe and North America, but rare here. The window units weigh and cost more, but provide extremely low U-values and excellent sound proofing.

Within an IGU’s frame, the panes of glass are held apart by a spacer. A wider gap gives better insulation – 12 mm is regarded as the best. Likewise, an IGU will prevent even more heat transfer if the cavity is filled with an inert gas, such as argon, rather than air. “With argon, you get about a 15 per cent improvement in U-value,” Smith says.

IGUs also perform strongly in bushfire attack conditions. “Double glazing works really well in the bushfire tests because the insulation barrier stops the radiant heat coming through the glass,” he says. This year, all states and territories will introduce a new standard for windows and doors in bushfire prone areas. So far, few products have been tested to the top levels.

Smith says the extra cost between single and double glazing can be between 50 and 100 per cent, depending on the company and the product. Householders can spend from a few thousand, to tens of thousands of dollars extra. “There’s a huge variance. The best bet is to shop around – there are good deals and really good products out there.”

Glazing
Glass is no longer just plain old glass. It now comes in a dazzling range of coatings and tints that will help keep your energy bills down.

Low emissivity (low-e) glass has a transparent metallic coating that reduces the pane’s U-value. “Low-e glass can significantly reduce the amount of heat that travels through your windows, keeping your house more comfortable in both summer and winter,” says Jamie Rice, vice-president of the Australian Glass and Glazing Association. It can also curtail UV light and reduce fading in furnishings.

Single-glazed low-e coated glass is a good option for people who want a step up from standard glass but can’t stretch their budgets to double glazing. However, it’s far more effective when placed inside an IGU – it can reduce the U-value of a double glazed window by half again.

Tinted glass cuts the heat transmitted into the home from direct sunlight. Available in a range of colours, tints are especially suited to west-facing windows that receive direct, summer afternoon sun. “The problem with standard tints has been that to improve the performance you end up cutting out light,” says Rice. “But there’s now a more sophisticated product, called spectrally selective tinted glass, which significantly increases solar control and only slightly decreases light transmission.”

Low-e coatings and tints can be used in combination. Together, they reduce both the U-value and the SHGC, making for a window that’s ideal for keeping out the heat.

Frames
Most window frames in Australia are made from aluminium. They’re cheap and versatile, but conduct heat very easily, which means they slice the insulating performance by up to 30 per cent. Thermally broken aluminium or composite frames offer better insulation, but they’re much more costly and, for the time being, not widely available.

Timber frames also have significantly lower U-values than aluminium. Edith Paarhammer, from Victorian window manufacturer Paarhammer, argues that although timber is more expensive, it performs better than any other framing material.

She recommends that eco-conscious buyers choose products made from either plantation timber or Forest Stewardship Council (FSC) certified timber. “It’s also very important that the frames are substantial, not flimsy,” she says. “And make sure they have seals all around, so there are no draughts.”

Another high performing frame is uPVC. Only recently introduced into this country, it has a comparable thermal performance to timber, but is cheaper. Warren Miles from Ecovue says a double glazed uPVC window can cost just 25 per cent more than equivalent single glazed aluminium.

Miles says it’s crucial that buyers look for frames that minimise air leakage. “You need a complete seal between the window and the frame, and also between the frame and the structure of the building. If you can’t achieve that you may as well not worry so much about the glazing.”

Miles says it’s crucial that buyers look for frames that accommodate double glazing while also minimising air leakage. “You need a complete seal between the window and the frame, and also between the frame and the structure of the building. Reducing air infiltration is a significant part of energy efficiency.”

Few businesses are specialist window installers, although some manufacturers can do the job. You can find them listed on the Australian Window Association website (www.awa.org.au).

Retrofitting
If you’re in an existing house and want to improve your windows, you have several options. The most effective and expensive way is to remove and replace the entire window units. In some systems you can replace the glass alone.

It’s also possible to retrofit double glazing, either with glass secondary window systems or cheaper acrylic panes that attach to your window frame using magnets. Cheaper still (but less effective) is Clear Comfort, a membrane that you tape to the window frame and make taut by shrinking with a hairdryer (a 10-metre kit costs only $180).

Films are an efficient way to cut solar heat gain on existing windows. They range from almost transparent to dark grey and cost between $60 and $100 per square metre, installed. They are also available with low-e coatings.

Glossary of terms
U-value: the measure of a window’s heat conduction. High insulating windows have U-values from about 3.5 down to 1.4. U-value is the inverse of the R-value.

SHGC: Solar Heat Gain Coefficient. The measure of the heat transmitted through the window when the sun strikes it directly; 0.8 is high, 0.2 is very low.

IGU: Insulating Glazing Unit. Double or triple-glazed window systems, which have sealed cavities between the glass layers.

Low-e glass: glass with a low-emissivity, metallic coating that improves its insulating qualities. Some low-e coatings also reduce the SHGC.

Spectrally selective glass: glass that allows lots of light in, while cutting out unwanted UV and solar heat gain.

A naturally warm home

This is an excerpt from an article in Sanctuary magazine issue 3.

By making a few changes to your home you can considerably reduce your heating bills and stay comfortable in the process.

Design for warmth

The cheapest way to heat your home is to use the warmth of the sun. If you are building or renovating, include passive design principles in your plans to let the winter sun in and keep the summer sun out. Position the daytime living areas so that they face north, with windows strategically placed to let in the winter sun and shaded by eaves, sails or external blinds during summer.

In cooler climates, thermal mass can help regulate the temperature inside the house, especially when there is a big difference between day and night outdoor temperatures. Use building materials that have high thermal mass such as concrete, bricks and tiles to absorb heat during the day and radiate the warmth back into the home during the night.

Changes around the home

Even if you are not building there are some measures that you can take to stop heat escaping from the house. Good insulation is a must. Insulation is like a barrier, preventing heat passing in and out of the house and can be placed in the ceiling, walls and floor. When looking for insulation check its R-value; the higher the value the greater the level of insulation.

Do a walk around your home with a candle, using the flame to show if there are any drafts. Place draught excluders, such as under-door strips, and foam door and window seals around doors and windows. They are low cost, very effective and are one of the simplest ways to reduce energy use. Replace or seal off open air vents and exhaust fans that allow warm air to escape into the roof cavity or the outside air. Don’t forget gaps between walls and skirting boards, and even the gaps between floorboards—these gaps may be small, but put together they can make for a great deal of cold air entering the house, especially when it is windy outside.

Shade treatments for old homes

This is an excerpt from an article in Sanctuary magazine issue 7.

When the heat is on and it’s streaming through your windows, you must think past the glazing. “External shading is the only way to significantly improve summer comfort,” advises Andreas Sederof of Sunpower.

The Victorians made extensive use of shutters, which on east and west-facing walls are still a fantastic investment.

In many Victorian-period houses, when the shutters fell into disrepair they were not replaced. Recesses on the window frame show where they were set. If you want to stay true to the Victorian style, the old shutters were two leaves fitted with louvres on a slant. They were also painted (in heritage colours, of course!).

Awnings, pergolas and deciduous plantings can be used to shade the high summer sun on north-facing windows while still permitting in the low winter sun. The Victorians also used canvas awnings on balconies and verandas.

Curtains

Another way to reduce winter heat loss – and some summer heat gain – through your old windows is curtains. “Given the difficulties of installing double glazing, curtains and pelmets can be very useful”, says Paul Downton of Ecopolis.

Adds Maurice Beinat of ecoMaster: “Full length drapes are best as they usually extend well past the edge of the window unit. If you don’t like pelmets it is an easy task to install invisible pelmets” – pearl-coloured Perspex that performs the same function as the bulky box pelmet.

The downside to curtains is that they cut out daylight. And proper heavy curtains can be very expensive.

Sash windows

This is an excerpt from an article in Sanctuary magazine issue 7.

The panels on the old double-hung sash windows are a common source of draughts, and their thin glazing is an insulation disaster – but replace them with something modern that’s out of character and you could be stripping thousands off your resale value.

It’s also important not to underestimate the environmental benefits of retaining your old windows. Replacing old features entails waste – unless you recycle in which case you’re merely trusting that someone else will adopt the “inefficient” technology you discarded. It also means installing a new window, whose embodied energy, the energy invested in its manufacture, transport etc, will offset its efficiencies for some time.

And old windows are not as inefficient as all that. As Paul Downton, principal architect of Ecopolis Architects, points out, “old sash windows provide very good controllable ventilation options that other windows do not”.

Sash windows are notoriously tricky to upgrade. There’s no point even looking at glazing solutions until you’ve sealed your window’s draughts, and while there are a range of draft-sealing solutions for sash windows opinions vary as to the effectiveness and appearance of each of them. ecoMaster make their own custom treatments, as do companies like Classic Windows and Sash Window Specialist.

Assuming you can seal your window against draughts, glazing treatments range from higher performing single glazing, to solar films, to discrete double-glazing substitutes such as Magnetite and Clear Comfort.

And yes, it is even possible to retrofit double glazing in old windows. “It’s a bit technical,” says Dick Clarke of Envirotecture, “but any competent carpenter can do it”.

Sun taming

This is an excerpt from an article in Sanctuary magazine issue 6.

It’s summer. The heat is intense and, somehow, it can seem nearly as hot inside as it is out. You have insulation and the blinds are drawn – what else can you do to raise comfort levels?

The first thing you should look at is shading. Imagine that for every square metre of glass in your house receiving direct sunlight, you are receiving a single-bar radiator’s worth of heat inside. Clearly, reducing the amount of direct sunlight that comes through your windows is going to make a big difference to your comfort levels. The good news is, you don’t need to pull down the blinds and live in the dark to keep your house cool. With a little strategically placed shading, you can block up to 90 per cent of all heat coming through your windows and still enjoy the view.

Shade structures can range from awnings to eaves, shutters, shade sails or trees. There is no one-size-fits-all solution. Your taste will be a factor, as will be the orientation of your windows.

The side of your house that you can do most with is the north, where the trick is to employ “horizontal” shade structures such as eaves and awnings. In summer these will act like a sun visor to exclude the high and hot summer sun. In winter, the sun, travelling low to the horizon, will still peek under your shade structures to allow in precious winter warmth.

Adjustable shading gives you maximum control over how much sun you invite into your living space. Contemporary shade sails can introduce elegant lines and spaces to your home, and allow you to choose exactly how much shade you get on any given day – particularly useful in spring and autumn. Mechanical awnings also offer choice and convenience.

Once you’ve got your shading, the other thing you should look at is the windows themselves. The type of window you use has a huge effect on how much heat gets in (and in winter, how much gets out).

For all-round performance in windows, you can’t go past double glazing. It’s a common misconception that double glazing is only useful in cold climates. In fact, it’s as good at keeping the heat out as it is at keeping it in. If you have north-facing windows that you can shade in summer and open to the sun in winter, then double glazing is a must.

If you have single-glazed windows and you’re thinking of upgrading, there are a few options. You can get double glazing installed, or you can go with one of several products designed to be attached to the inside of a window frame. Price will probably determine which option you choose.

Seal those draughts

This is an excerpt from an article in Sanctuary magazine issue 6.

Draughts can contribute up to 25 per cent of a home’s heat loss or gain. For new homes, choose well-made windows and doors with airtight seals and avoid gaps in the walls. Duct exhaust fans and fit dampers to chimneys and flues. In existing homes, using draft strips on windows and doors can make a huge difference: it can be as simple as using a stuffed snake!

Go for double glazing

This is an excerpt from an article in Sanctuary magazine issue 6.

Even if you’ve installed insulation in the ceiling and walls, much of that good work could be undone by your windows. Heat gain through an unshaded window can be 100 times greater than though the same area of insulated wall, while heat loss can be 10 times higher.

Double glazing dramatically increases the thermal performance of windows. If your current home has single-glazed windows, installing double glazing is one of the best ways to quickly upgrade your home’s energy performance. And don’t baulk at the cost. Studies by the Australian Glass and Glazing Association showed an average cost payback of just over five years.

Get shady

This is an excerpt from an article in Sanctuary magazine issue 6.

Get to know the difference between vertical and horizontal shade structures, and permanent and adjustable shade structures, and know where to use them. Employed properly, shade structures will make your house a cool haven in summer, while allowing in that precious sunlight during winter.