Reflective window films pros and cons


I live in an apartment with large northwest facing glass doors leading to a balcony and central atrium. Even though we are good friends with our neighbours across the atrium, it would be nice to have a little more privacy than we currently do. I don’t like having our blinds (made with “Ecoview” fabric) down all day and I was thinking of getting a window treatment that makes the glass reflective so you can’t see in. Would this adversely affect heat transmission in the winter? Would it also reduce the amount of light entering the living area? We also have a retractable awning that helps keep the sun off the windows in summer.

— Rosemary


Reflective window films that reflect light and thus provide privacy will indeed reduce solar gain in winter. The external awnings are the best way of regulating solar gain, day by day, regardless of what the seasonal averages suggest. The other characteristic of reflective films is that they rely on a particular imbalance of light, in that they will reflect to the brightest side. This is outwards during the day, but at night it is the reverse, thus making your blinds essential for privacy in any case.

The “Ecoview” blinds you already have are probably the best option for privacy while still getting some of the view, although when down they too will block some winter solar heat gain.

— Dick Clarke


Achieving a high insulation rating


We’re building a winery shed in Yarragon, West Gippsland, from recycled wood and tin. We’d like to use pure wool for the insulation but have not been able to achieve a high enough rating with the space available. We’re aiming for R4 minimum with 150mm deep roof perlins and 100mm wall spacing. Do you have any suggestions?

— Rachel


It is difficult (if not impossible) to get an R4 rating with the spaces you have available. Most insulation materials come in R values of between R1.5 and R3.5. To achieve higher R values, bulk insulation batts can be as much as 300mm thick. Use of polystyrene products with a reflective surface can give reasonably high R values for little width, but you will have to use a combination of a material such as Foilboard (www. or Aircell (www. plus a bulk insulation to achieve R4.

There is one other possibility: thick polystyrene insulation panels of the type used for cool rooms may give you a higher R value. I don’t know of anyone using them in homes though, and you would probably have to get them custom made, but it might be worth investigating.

I recommend you discuss this with your designer. You may have to compromise on either wall and ceiling thickness or on insulation values.

— Mick Harris

Building with bamboo

Lightweight and with the tensile weight-for-weight strength of mild steel, bamboo has been used as a building material across Asia and beyond for thousands of years. A grass rather than a timber, in the right conditions bamboo can grow up to 30 centimetres a day, and can be harvested without destroying the original plant. These qualities make bamboo one of the world’s most sustainable building materials.

Because of its fast growing time, ability to absorb carbon and its versatility, bamboo is frequently used in ‘green’ building products in Australia. It is commonly used as a laminate, for its fibre, or less commonly, as a dried, usually woven material.

Bamboo building products in Australia are almost entirely imported from Asia, predominantly due to lower labour costs in both the production of the plant and the manufacturing of the resulting products. The impact of bamboo as a monoculture, the use of pesticides and toxic adhesives in the growth and manufacturing process, as well as shipping and transport, can all compromise bamboo’s environmental credentials, so it pays to investigate available choices.

Although bamboo is used in a wide range of products in Australia it is not currently rated as a structural building material, but this could change. Architectural designer at Cave Urban, Nici Long, designs and builds bamboo structures, including temporary pavilions and shelters for special events such as the annual Woodford Folk Festival in Queensland. She values bamboo for its sustainability and ease of use.

“Bamboo is incredibly easy to work with so a whole community can get involved with a project,” she says. “It’s lightweight, with low embodied energy and it’s biodegradable.”

As a material for permanent structures, building with bamboo does have some significant shortcomings. As a grass, bamboo’s cellular structure is more water absorbent than timber, which can promote fungal growth and rot. Its high starch content makes it susceptible to insect attack, while its internal structure means that inappropriately placed holes can cause the lengths to split. However, as Nici argues, there are solutions on the horizon. Bamboo is already treated with a natural salt, borax, for powderpost beetle, and its growing popularity in the west is prompting research into alternatives, such as maximising optimal harvest time to enhance natural seasoning. This could potentially reduce or eliminate the need for additional treatments.

Sustainable House Day preview

Take a sneak peek inside some of Australia’s most environmentally friendly houses this September as part of Sustainable House Day. This is a chance to glean some of the hard-won dos and don’ts for your green building project, and see first-hand the results from those that have made it out the other side.

Homes are open on September 7 and 14 across Australia, with homeowners on hand to offer advice on replicating the sustainable features of their properties. This year features a new straw bale dwelling at an eco village outside Adelaide, an 8.5 Star infill development in Geelong, a Gold Coast Hinterland home with native gardens and even architect Caroline Pidcock’s Sydney terrace, deep in the midst of renovation.

Sanctuary 28 profiles eight of the houses open across Australia.

Sydney – The architect’s home

New South Wales – Organic retreat

Queensland – Cool hinterland home

Western Australia – City beach home

South Australia – Eco village home

Tasmania – Mountain straw bale house

Victoria – Geelong 8.5 Star house

Sustainable House Day was first held in 2001 and is now managed under EnviroEvents of EnviroShop. It’s grown to be a calendar favourite for the environmentally-savvy with recent events seeing 200 homes open their doors to over 40,000 people, signalling the growing interest in sustainable living in Australia.

Sustainable House Day gives anyone from industry professional to curious novice an insight into just how much can be gained from going green.

Visit the Sustainable House Day website for a full list of houses open around the country on September 7 and 14.

The architect’s home

Ever wondered how an architect would update their home? This Sustainable House Day Caroline Pidcock will open the doors to her own heritage-listed three-storey terrace at Millers Point – mid-renovation.

Naturally the restoration and renovation by Pidcock, a leading sustainable architect, and her husband, also an architect, will be as sustainable as possible especially in regards to energy efficiency as well as a 2.4 kilowatt solar electricity system, a heat pump hot water system and a real time wireless energy meter. The renovation also features recycled timber throughout, no-VOC paints and timber finishes and double glazing retrofits to improve windows.

She is also wonderfully candid about her experience. “I now realise how important it is to follow the rules I advise for my clients,” says Caroline. “How do I know? Because I have broken nearly all of them!” Read more about Caroline’s project at her blog:’s-own- renovation.aspx

Organic retreat

Environmentally friendly homes and beautiful vistas seem to go hand in hand and Girragirra retreat is no exception. This new residence on a 50 acre organic farm at Forbes overlooks a billabong of the Lachlan River and spreads across two pavilions – one is Wendy and Kim’s new home, the other is a self-contained holiday rental.

Wendy and Kim are fourth generation farmers with a passion for sustainable living and regenerative farming practices. Their retreat was designed by Environa Studio to stay naturally warm in winter and cool in summer. Sun streams in the wide north-facing front in the cooler months while cross flow ventilation, loads of insulation and double glazing provide year round thermal comfort.

The house is clad in corrugated iron repurposed from an old warehouse, the internal joinery courtesy of a felled river red gum, milled onsite, while all waste was reused or recycled, down to the cardboard packaging which was placed in pits to act as a water-soak for trees.

A ‘big lid’ roof collects around 200,000 litres of rain water. A 10 kilowatt solar array produces more energy than the owners can use, and a solar hydronic hot water and underfloor heating system has proved a big energy saver.

City Beach Home

This City Beach home is so close to Perth’s beautiful beaches that you can see the ocean from the balcony. It’s a classic example of a contemporary family home designed with sustainability principles without compromising on comfort.

The owners Mark and Helen asked Solar Dwellings to create a spacious home with separate living areas for them and their growing family, with some communal areas to encourage family interaction. Just as essential though, was the home’s ecological footprint, natural comfort and energy and water efficiency. The house is designed to maximise passive heating and cooling through high levels of insulation, shading, optimal orientation and window placement. The ocean location makes the most of natural breeze paths for summer cooling.

The house also includes full waste water recycling, a 20,000 litre rain water tank, solar hot water, LED and natural lighting and energy efficient appliances.

This is a large family home that includes a home office, pool and rumpus room, yet Mark and Helen receive minimal electricity bills and have even received credit for returning energy to the grid from their solar electricity system.

Eco village home

Life in an eco village sounds ideal. Particularly one that holds creative writing courses, lantern-making workshops for children and art exhibitions for residents. While the Aldinga Arts Eco Village is a haven for creative types, it also benefits from sustainable design throughout, from all homes through to communal spaces.

The emphasis at Aldinga is on bringing people together. The village is committed to retaining over 40 per cent of the complex as open space for the community. Residents use permaculture principles wherever possible, including in the design of the village farm and its proposed organic food production. The private lots are orientated within 30 degrees of north to aid passive solar design, with all homes designed around village sustainability guidelines. Ongoing living costs are kept low with rainwater the main water source for all homes and many powered with solar panels.

One of the village’s newer houses is open as part of Sustainable House Day. It’s a straw bale, Colorbond and glass construction, thoughtfully designed around a courtyard, providing shelter and allowing winter sun into living areas. The straw bale creates texture, curves and embedded elements throughout the home.