Window glazing

VEU activity 13 - Double glazing

VEU activity 14 - Window film

This article answers common questions about claiming rebate for installing double glazed windows, film or secondary glazing.

What sort of windows/window film I should get?

You should consult your window supplier/manufacturer for advice what are the best windows for your home. However that advice can be biased or limited to the products they offer. As the windows cost can easily be thousands of dollars, consider getting independent advice. Even if you have to pay for an assessment, $200-$300 is well worth spending as it can save you thousands and a lot of stress of getting a product that does not do what you expected.

You can do your own research, starting from this text then searching the web for more information.

We also offer free advice on specific product, if you have a quote and it has the specs or codes we can advise on rebate and general note of suitability.

To get specific advice you will need Scorecard assessment. These are paid assessments and cover the entire house not just windows but you can advise the assessor you are specifically interested in windows. We suggested Scorecard because it is controlled by our government and requires high quality standards and knowledge of the assessors which must be accredited to perform the assessments. Scorecard is also subsidized by VEU rebate which makes it even more useful.

We are also accredited for providing Scorecard assessments.

You can read about this service on Energy Assessments page.

And you can register for Scorecard rebate at the same time as for double glazing, by pressing Register button.

We can process both Scorecard rebate and double glazing rebate for you. We can process Scorecard rebate done by any assessor (not just our own assessments) as long as the assessor is accredited. You are not obliged to use our service - for a list of assessors available in your area click here. Our own service area information is here

Now, back to the windows ...

How does the rebate work?

You apply for the rebate after you installed double glazed windows or film. When processed and approved by our regulator we will pay cash to your nominated account (the process takes 2 to 4 weeks from lodging).

How much rebate can I get?

For the film, the rebate depends on the brand and model of the product used, your postcode (the climate) and the total area of the windows. For double glazing it also depends on the type of the frame being used. If you have a quote from the installer, we can estimate the rebate you will receive.

But in general, the rebates are not very big. For the film, the rebate is around $10/sqm. For double glazing the rebate is $30-$40/sqm. A minimum of 5 sqm applies to both activities.

What do I have to do?

You need to

- Get a quote from your selected windows maker or installer. Best to get 2 or 3 as window prices can vary.

- Ensure the product is approved and installed by qualified tradesman

- Take pictures before and after (1 or 2 windows will do, entire project welcome, but not rrequired)

- Provide invoice for works specifying brand and model of glass (or film) products used

- Provide installer information for approval (pic of D/L and RBP licence)

- Fill in and sign the claim form

Does the installer need to be accredited with VEU?

No. But the installer must have a builder's licence (RBP = Registered Building Practitioner) or completed retrofit course, and be approved by ESC/VEU. We apply for approval but we need a picture of RBP registration/card and a picture of their driver's licence. Talk to your installer early to make sure these documents will be available.

How do I know the product is approved for rebate?

To be approved for rebate the windows must be registered on WERS database and have minimum performance level as recorded on the database. The requirements are U-Value<=4 and Heating stars >= 4. You can read about those specifications below.

For WERS database search click here

However, it the search doesn't always display all registered products, so to search by manufacturer, click here

and for films click here

Where do I start?

To process the rebate, register on our Register page. We will send you approved product list, if available, the claim form and a step-by-step checklist how complete the activity and collect the required evidence.

Window specifications explained

The window information you are likely to encounter when shopping for double glazing is likely to include a lot of specifications. Some will be relevant, others will be just added features unrelated to thermal performance. And some can be misleading. For example, films and double glazing panels fitted into existing frames may have really good specs which is why they are often marketed using these specs. But window's performance is not just the glass and film, it also includes the frame and if the frame is bad, it can result in overall performance being significantly less than the specifications of the product used. Therefore, when considering a retrofit product, always ask what is it's performance when applied to your existing window glass and/or frame.

Marketing

Marketing techniques can be used to showcase a really good product, but they can also be used to convince customers they are getting what they need or to close the sale. Do not accept any claims on face value. Ignore buzzwords like Low-E, Ultra-This-Or-That. Don't get dazzled by pretty pictures showing how the windows work. Instead, have a list of specifications for your windows and ask the salesperson abut those specs.

Climate consideration

The specification below are considered mainly in the context of Victorian mild and cold climate which is mostly about heating (ie more cold days than hot). Our mild and cold climates put a challenge on the specs, particularly how the effect of direct sun is handled. We want it in the house in winter so the sun heats up the house for free, but we don't want it in summer. A window which reflects direct sun will be great in summer, but will require a lot more appliance heating in winter. Because of that, all rating programs and thermal recommendations favour windows which let more sun in. And in summer, when we don't want the direct sun shine into our houses, we can use shading, internal (heavy drapes with pelmets, honeycomb blinds, plantation blinds etc) or external (shutters, good eaves, screens, awning blinds).

Insulation

You've probably heard about insulation in the walls, and that it can be in form of batts and reflective wrap. DOuble glazing is like insulating your windows, the U-Value is the equivalent of R-Value batts, and the SHGC is about reflective property of the window.

U-Value

U-value is a measure of how much heat is transferred through the window. That is, how much heat escapes through the window in winter or how much heat enters into the house in summer. The lower U-value the better the window. Some of the best windows have U-Value around 2. To be approved for double glazing rebate the U-value of the window must be maximum 4.

SHGC

Solar Heat Gain Coefficient is an indication how much direct sun will be transferred through the window. The higher SHGC value the more sun it lets through. In Victorian climates, which are mainly about heating, high SHGC combined with good shading is generally considered better.

Low-E

Low-E is a clear coating applied to the window to reflect direct sun (low-emissivity). The low-e is reflected in low SHGC but it can also lower the U-Value, which is why it has become "overused" in marketing. If a window's SHGC is 0.50 or higher then its definitely NOT low-e.

Heating Stars

Heating star rating of a window, in stars from 0 to 10, compared to standard window, 3mm single glazed in aluminum frame. The higher stars the better window performance. For a VEU rebate the window must be rated at least 4 stars.

Frame

Frame material is an important factor as much of the heat can be transferred though the frame. Standard aluminum frame is the worst performer, you should consider either timber, plastic or composite frames or, if you like the aluminum look, use thermally broken frames.

The specifications in this section are additional features your windows may come with, not related to thermal performance and usually come at additional cost, but could be useful for reasons other than saving energy.

Sound proofing

Double glazing significantly reduces sound without any special features. If the noise outside is pretty bad, you may want to consider additional protection

Tint

Window tint works on visible spectrum and therefore doesn't affect or improve thermal performance. It does reduce the amount of light in the room, if that is what you need or an effect you want to create.

UV protection

Works on UV spectrum and like tinting does not affect thermal performance. But as UV is harmful and can cause skin cancer, its a good feature to have overall, but especially if you're planning to have windows with high SHGC to let the direct sun into the house in winter.

Tempered glass

Special glass treatment causing it to break into small, round bits instead of sharp shards. Good safety measure especially for families with children.

Laminated glass

Of the two sheets of glass that make double glazing, one could be laminated, that is made of two thinner sheets of glass bonded together. Not as strong to break as tempered glass but it will not shatter into pieces, the glass will crack in a spiderweb-like pattern but the pieces will be held together by the bonding layer between the two sheets.

Laminated glass has many good features. It increases the safety as it is very hard for someone to break it and enter the house. It adds soundproofing, the twin layer dampens the sound. And thicker than a single sheet of glass, it improves thermal performance as well.

For more information on benefits of double glazing visit our assessment site BeEnergyEfficient (info section)