Double Glazing

Double Glazing – Is it for you?

Simply put, Double Glazing is window insulation either for temperature, or noise or for both. As well as the option of replacing your single glazing with double glazed glass units, other options for insulating your windows are: Secondary Glazing, LowE Insulating Film and thermal drapes.  We won’t go into thermal drapes here as they are only partially effective, but to learn more about the other options, please read on…

We all know the importance of ceiling insulation, but your home’s insulation package is only as good as its weakest link. With good ceiling and wall insulation, single glazed windows, especially in aluminium frames, are the weakest link, not only for thermal insulation but also for sound and water ingress.

Improved insulation standards mean new homes are now pretty much all double glazed. This is a great regulation by the government and is helping New Zealand to catch up to the rest of the world in home insulation comfort. But, if you are living with single glazing now, what can you do?

Window insulation is a far more complex subject than most people realise.  So many variables and every home is different. For the best results you need to make the right choices for your particular needs and your budget. And the best way to make the right choices is to talk to experts like us!

We will assess your home and listen to your needs.  Only when we have the full picture will we make suggestions as to the best option or combination of options that will best suit your unique home.  Because we have all the options available, we are not biased towards any one particular solution, we want what is best for you.

Retrofit Double Glazing into existing frames

Full Replacement of the frames and the glass

Secondary Glazing

LowE Insulating Window Film

Saving heat loss, noise reduction, solar heat reduction, reduced condensation, reduced UV damage, eliminating drafts, improved safety, better energy efficiency and added value. What are the most important benefits for you?

Young girl by double glazed window

The Potential Benefits of Double Glazing

  • Warmer in Winter
  • Cooler in Summer
  • Saving precious Energy
  • Reducing Condensation
  • Reducing UV Damage
  • Reducing Noise Invasion
  • Improving Safety
  • Adding Value & Saleability

Retrofit Double Glazing

We use your existing aluminium frames and just replace the current single pane glass with new double glazed panes.

Full Replacement Double Glazing

We remove your existing frames and glass, and replace them with brand new frames – preferably UPVC  for the ultimate in quality- containing double glazed panes.

Secondary Glazing

Secondary Glazing either attaches to your existing window frames to create a double glazing system, or is a separate sliding system that completely insulates the existing window.

Want to know more?

Check out our Double Glazing Frequently Asked Questions!

Retrofit Double Glazing

Double glaze your existing windows

Retrofit Double Glazing is fitting double glazed glass units into your existing joinery.

For fixed, or non opening windows, we remove the single glass and replace it with IGUs or insulated glass units.  These are factory made units that are two pieces of glass, sealed together with an air gap between them. New aluminium clip bead is cut to size and fitted to secure these into your frames.

Opening windows, or sashes, are replaced with all new frames complete with the IGUs installed. All the new aluminium is powder coated to match the colour of your existing joinery as closely as possible.

Retrofit is a good option if your window joinery is in good condition and if, like us, you hate the thought of throwing away perfectly good frames! However you do need to bear in mind that it is only insulating the glass part of your window package.  If your frames are aluminium, then that part is still a source of heat loss and is still susceptible to condensation.

There are a number of choices available in the make up of the IGU. Certain specifications are required by the glazing regulations, like safety glass in bathrooms and stairwells for example, but you can also choose several other options that will improve the performance of the units. Using laminate glass for example, provides better sound insulation, almost total UV blockage and like a car windscreen, is very hard to break through. LowE glass provides a heat reflecting film on the glass that considerably improves the performance for thermal insulation. There are several tint options for privacy, or reducing glare and you can opt for Argon gas in the space between the panes of glass instead of air as Argon is denser than air and is a better insulator.


Full Replacement Double Glazing

Renew your windows for a new look and the best in insulation

If your existing joinery has seen its day, or you want to upgrade to thermally insulated aluminium frames or, best of all, change to UPVC frames, then full replacement is for you.

We will remove the existing timber or aluminium frames and replace them with brand new aluminium or UPVC frames in whatever configuration you like.  This is the option if you would like to renew old joinery, or change a window into a ranchslider for example.

All the same glass options are available as listed in the section above for retrofit, but with full replacement you have the added option of changing to insulated aluminium, or UPVC frames.  The insulated aluminium frames are called thermal break or thermal heart and make a considerable difference to the overall performance of the window. Aluminium is not even slightly an insulator. The temperature of plain aluminium frames is pretty close to that of the outside air and in the middle of a winter’s night that is pretty cold!  Thermal break aluminium has an insulated section built into it that separates the inside and outside layers of the frame so that they are insulated from each other. Obviously more expensive than regular aluminium, but when you have a lot of aluminium framing, as in the case of bifold doors for example, it can make a very big difference.

Full replacement is more expensive than retrofit double glazing, but what a difference and what an investment…

A window changed to a ranchslider by full replacement



UPVC Joinery - The ULTIMATE in window and door joinery


UPVC Joinery blurb

UPVC really IS the ultimate material to use in your window and door joinery. Not only does is provide vastly better insulation than aluminium, it is stronger, more secure, more resistant to water ingress and provides better sound proofing.


And we consider the Aluplast UPVC joinery that we can fit into your home is the best UPVC product available in New Zealand. Made in Germany by the 5th biggest manufacturer in Europe, Aluplast have developed a UPVC formula that is second to none in UV resistance. If you are in doubt about the UV resistance of UPVC, check out the history of Palliside building cladding. That product has been tolerating New Zealand conditions for over 16 years and still looks as good as new. And Aluplast is an even more UV resistant formula.

A typical aluminium framed window has a “U” rating (a measure of heat loss) of 5 or 6. An equivilent unit in Aluplast UPVC has a “U” rating of less than 2.

Sealed inside the UPVC that you actually see, is a very strong, box section, galvanised steel frame that provides great strength and rigidity.

Windows and door have multiple locking points and are one of the hardest ranges of joinery to break into.

Because the both the corner joins and the weather seals are welded during the assembly process, there is no opportunity for any water or draughts to penetrate.


Bigger air spaces within the joinery, better seals and a more sound resisting material all make for great sound proofing but this does need to be coupled with the right choice of glass options for best results.

Secondary Glazing

Heritage Secondary Glazing is highly effective, yet low cost, double glazing

Heritage Secondary Glazing sliding system over timber joinery


Heritage secondary glazing sliding system over aluminium joinery


We call our secondary glazing system Heritage. It uses the type of system that has been tried and tested in the UK for many years and is extremely efficient, yet very economical, compared to retrofit double glazing.

Secondary glazing is glazing that fits inside your existing glass panels, so your windows are the first layer of the double glazing and the secondary glazing is the second layer. We use high quality aluminium frames which are powder coated to match your existing joinery – aluminium or timber – and optical grade acrylic instead of glass. The advantages of acrylic are that it is lighter than glass and much safer, it is a much better insulator than glass and it has a very high UV block.

There are two types of Heritage secondary glazing: Sliding and Fixed, and both have their place.

The sliding system gives the best insulation as it is completely separate from the existing window and so provides a total thermal break. It effectively insulates the whole window including the cold aluminium frame and this system is THE most effective for noise reduction. When you want to open a window, or clean it, you slide one panel of the secondary glazing across to access it. You can easily remove one or all of the secondary glazing panels if need be and for summer time, you can replace one of them with a fly screen.

The fixed system is attached to the inside of your existing frames, ususally with an insulated clip bead system. With this system, all your existing window hardware, like handles and safety catches, are readjusted to work exactly the same way that they always have.

This video shows the difference Heritage Secondary Glazing makes to condensation



Talk to the Experts

Our consultants are experts and will guide you to the best solution for your home and your needs.

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