Though double glazed windows will, in the long term, provide lower bills, low greenhouse emissions and comfortable homes and buildings, we cannot ignore the fact that replacing the typical single glazed window would mean a cost so expensive, not only with the glass itself but with appropriate frame needed as well. Unless our building code mandates it, I am sure many will continue to ignore the facts about thermal efficiency, which will be so helpful both for the extreme heat of summer and the coldness of winter. When industry standards, building codes, and government policies focus effectively on energy and thermal efficiency in building construction, maybe a less expensive double glazed glass will be available in the market and attract more users to choose them.

I will put forward a different view point – maybe it is just a lack of education, if you don't know the how and why, and no one can prove to you that you will actually benefit from it, then you are right to be sceptical about it.
Energy efficiency can be designed and verified in the building design process, quite easily and cost effectively. There are software products and design strategies that can be used within the current design timelines and fees that will result in savings in both the short and long term.
I have witnessed the use of the BCA section J analysis software by Darren O'Dea. It does a very good job, very quickly at highlighting design changes that will result in the best energy efficiency from the design.
Sefaira is also a software package I have used to demonstrate the impacts of design changes that impact energy efficiency, while allowing optimising the building for daylighting and views.
IES-VE does a very good job and if used by an experienced operator can provide answers quickly and cost effectively at the very start of a project, determining the best orientation of a building to achieve energy efficiency.
My point is the tools and capabilities exist, the efficiency of the operators and understanding architectural intent are the areas where we need to improve so that providing these services and analysis of buildings becomes the norm.
Education of the benefits of having building physicists work within the architectural design environment is key to achieving the long term outcomes we are all striving for.

Whilst I agree that it is worthy of consideration on any new build, there are also glazing films which are also great at significantly reducing glass surface heat transference.

As for those building's you see with the lights on, they are often either being cleaned or are 24hr operations by the tenant.

Many buildings start out with intelligent lighting controls, etc. only to have these disrupted and disabled by tenancy fitout. Same thing with supplementary A/C controls not integrated into the base build so that they oppose each other.

Every building has unique features and these need to be addressed by appropriate design and installation at every change to structure, equipment, layout, occupation, furniture & fittings.

There are a number of reasons in my opinion. Here's one:

Building services & energy engineers are usually involved far too late in the design process. Good design takes a bit of time. Integrated, first-principles lean design is the best way to design buildings that are both cost-effective to build, operate & maintain, & be energy efficient. McDonalds menu star rating systems aren't the best way – it's just an easy way to market it, unfortunately it often ends up as just a green-washing exercise.

Integrated design can't happen unless all design disciplines are involved from the start & are given equal status. You won't see Toyota designers come up with a beautiful, heavy, expensive vehicle design & then say to the engineers "just make an engine to fit in there somewhere & make it cheap", or "We've come in over budget but we need to keep the body & interior as-is, Can we use a 1980's engine design to save money". It just wouldn't happen – yet it happens all the time with buildings.

Interesting comments! A few from my experience. We designed and built a passive house following the International Passive House Standard which models the design to predict a maximum energy use per sqm per annum. (see facebook page superpodhome) In Australian terms it is an 8.7 star house but the energy efficiencies are just not measured on the Nathers scale. This house is so good it needs NO heating and NO cooling in Melbourne.
There is no risk of us leaving the heater on all winter because we don't have one.
As for windows we got triple glazed and boy was that hard to get here!
Thermally efficient window frames are also almost impossible to get here. Overseas they are 10 – 20 years ahead of us.
One big difference is that there is little proper testing and data of the performance of building products here. Some companies assert certain figures but have no spec sheets to back it up. You can't buy those products and hope to comply with the Passive House Standard.
Yes we need to change our laws, our perceptions, and our practices. In the meantime, people can still choose to voluntarily build better buildings (pending legal change which might be 10+ years away).

Darren you are quite correct. I think everyone knows this sustainable issue and star rating in all a con job to keep people employed that thaught all this up.
To reduce power consumption is very easy and people would know that lighting, HVAC&R are the biggest users of power. As tou quite rightly say why dont you see more double glazing. All costs could be offset by energy saving and all these funds that are given out is not required. This will save the government millions of wasted dollars.
They always looking at cutting funds to areas that need it such as the blind and disabled. But willing to hand out lots of money to crap.

Great comments above… 2 comments of concern though in relation to the article….

1. “It is estimated that the double glazed window market is less than five per cent (in Australia)”… not sure where that is from as it does not reflect what i am seeing!

2. “Using double glazing can result in significant savings of 40 per cent off energy bills for heating and cooling” …. the source (Woods Products Victoria) actual states” A significant saving of 40% off energy bills to heat and cool all residential and commercial buildings can be made if appropriate glazing is installed”. By misquoting the term “appropriate glazing” in replacement for “double glazing”, this article creates a very real misconceptions that double glazing is as effective across Australia as you move away equatorial regions….it simple is not!

well said. J6 the BCA Nabers are all garbage.
When people brag about a Nabers 6 star rated building but leave every light on 24/7 who is fooling who about been sustainable. And the government are also stupid for funding all this.
I saw a bunning shop get 250,000 or around that to upgrade lighting. What did the do. Kept all the hogh bays and added T5 high bays no fittings came out. So what was saved ZERO
but the government felt good and promotes the fact they gave bunning money.
Once again big companiez that can afford to do things themselves getting funding to waste energy.

For me, it's about accountability. Nobody is worried about Section J of the BCA because they won't get in trouble if they get it wrong. It's like speeding along a road and there is no police force to book you for it. Would you adhere to the speed limit? No! Even if a cop stopped you and said "Did you know you were speeding?" and you say "No." and then the cop says 'Well, yeah you were, so don't do it again. On your way." Would you change your behaviour? Of course not. It's only because cops give us massive fines, with a serious risk of losing our licences, that we have changed our driving behaviour over the last 2-3 decades. Until we have 'cops' booking people for not producing energy efficient buildings (especially with the risk of losing our licences!), no one is going to bother to change what they've always done. And as we go into the second decade of Section J, we can clearly see that this is true!

marisa. You are correct. It is very easy to make a building energy efficient with no capital outlay and no government assance required. I see too much government funding been given out for projects that do no more than waste energy.

There is a perception that its 'expensive' to design energy efficient buildings, statutory requirements are too lax in this area, energy costs too cheap, and a paradigm shift is still required at all levels of the design, technical, local govt, utility providers, construction, procurement, and facility management process to think differently so that our buildings are as efficient as possible. All too often there is no time in the design process to research what's needed, to properly weigh up the upfront costs against ongoing costs, and in the end it becomes all too hard and better the devil you know…….

After living in Central Queensland for 12 months and being sourounded by an explosion of development I feel I can comment on this subject. I also have an engineering background an architectural qualification. The domestic construction I observed in CQ was extremely poor but not only from an energy efficiency perspective. Insulation was completely omitted or only consisted of a thin layer directly under the roofing to prevent direct heat contact from steel roofing. Foil sheet on was was considered wall insulation (outlawed in NZ decades ago), plumbing water supply pipe work only clipped onto framing sporadically on the outside of framing in the brick veneer drainage cavity. Thermal envelopes serve to maintain an internal environment wether this requires heating or cooling.
But energy is so low cost due to all the coal fired power stations so where is the insentive for improvement?

After reading all the comments , Good article Sophi you have stirred the possum . The main problem is ,the building industry is made up of a large group of builders who fight amongst them selves to do the least for the least amount of money to the lowest standard & the client wants to pay as little as possible . Then there is the BS like , Just open a window , multi glazing is for cold climates , use brick or concrete on the exterior of the building . To top it off, why is a lot of professionals in the building industry blind , deaf & dumb when it comes to understanding ICF & how it really works . what is ICF ? Insulated Concrete Form . As builders in Australia we must stop building houses as we have in the past & just add some bandaids to fix the problems ,It does not work, we need a whole new approach .With ICF we are held back to 8 to 10 stars by inferior windows & Doors & it is the standards that need to change .

why do 6 star rated buildings have their lights on all night?. Why is it ok to use way over J6 IF GREEN POWER is used?
Energy efficient buildings are not efficient it is all a furphy to make people feel good

Australia is still debating how to keep energy prices low rather than how to reduce energy consumption!

The price of land and housing is very high – increasing property values are people's main concern. People think that having a house that might require some thought to manage temperatures, lighting costs etc might reduce the profitability of the investment.
The idea of saving money through having a more energy efficient house does not seem to be of interest to home owners. The attitude is that water comes from the tap as needed, hot or cold, the air conditioning keeps us cool, the heating keeps us warm. To have a home that is energy efficient due to care in its construction is not a common goal. Perhaps the costs of gas and electricity need to be come even more expensive to spark a desire for energy efficiency in Australia

With respect, NCC Section J is fairly demanding and looks at facade direction, surface area of glazing, then the important combination of frame and glass and uses Window Glazing Calculator to optimise each and every project.
Double glazing in hot climates holds heat in after the a/c stops and needs extra pulldown the next morning at the worst peak time. Aluminium frames that are not decoupled should be barred. New breed Low E glass can be close to double glazing in a single more economical unit.

This surprises me because I know Australia has a very effective Green Building Council and an Energy Efficiency Council. I campaigned strongly for greater Government recognition of the importance of Energy Efficiency a few years ago and thought the message had been understood. Now I'm based in Singapore and find that Government agencies and business gets the message and the public private partnership seems to be working. Of course more could be done, but it is obvious here – and in other Asian countries – that energy efficiency helps companies/buildings/businesses save money at the same time as saving energy.

In Queensland we have a new performance method to control heat in buildings both residential and commercial. It is called opening it up, open a window and allow passive heat controls and natural ventilation to reduce energy use and green house gases. Our buildings are designed to "Leak like sieves", which is appropriate in the subtropics. In high rise residential, often balconies provide shade in the best developments. Double glazing and thermal separation are excellent for Southern Australian conditions, however entirely different measures are required at the &quot.

Hi Sophi, excellent article, wise words! As double and triple glazed window manufacturers (timber) we have been trying to educate the market here in Australia for 25 years. Great to have reinforcement! Cheers, Edith

I think a large percentage of the industry would provide these answers to the headline is "Because clients aren't asking for it" or "It costs to much". I hear this way to many times from designers and builders. Every building, from commercial towers to single dwellings, should be highly energy efficient and should also use sustainable building materials and products inside and out. The building industry needs to practice sustainability as matter of course, day in day out. That's the only route to a responsible industry. Sustainable building is not just for the top end of town. The industry and associated suppliers need to get together on this and sort it out once and for all otherwise we keep floundering in the sustainable mud. We owe it to our community to produce healthy building stock.