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Why Choose PVC-U Window Frames?

Lower Hutt Home fitted with PVC-U window frames, by Thermalframe

Written by Ben McConnell

A product that is relatively fresh to the New Zealand market is PVC-U window frames. The product itself has been used worldwide for the last thirty or so years, however an out of date obsession with aluminium and timber windows has effected sales of PVC-U in our fair land.

Often window frames fall into the category of aesthetics rather than performance and sustainability when it comes to building homes. PVC-U window frames are here to shake up things up a bit. 

Aluminium frames have been the norm in New Zealand for some time now, and it’s easy to understand why. They are relatively cheap and offer easy installation, but the reality is you pay for what you get; a terrible insulator with aluminium’s thermal efficiency close to zero.

Timber window frames have been a popular choice for years in New Zealand homes, timber is long lasting and durable and is considered a renewable resource. However, timber is about 30% more expensive than aluminium window frames, and timber offers little in the way of insulation and function. 

PVC-U window frames are an attractive alternative to their aluminium counter parts. PVC stands for poly vinyl chloride, the U means that it is unplasticised, making for a robust and strong window frame.

PVC-U is a simple plastic made up of 57% standard salt, 40% ethylene, and 3% additives such as colouring and stabilisers.

Ethylene is found in plants which adds to the appeal of PVC-U window frames, as a renewable and reliable resource ethylene is a key ingredient that makes this technology so appealing.

Pvc-U window frames cross section image

With regard to insulation, PVC-U windows are excellent insulators, helping to reduce loss of heat in winter and helping your home to breath through summer. This occurs through the frame and sash of the PVC-U window frame that has been welded rather than using screws, as you would with an aluminium frame.

Matching the welding technique, PVC-U will be weathersealed ensuring that the window frames are water tight, and will remain so throughout their 40 year plus lifetime.

Price variations of PVC-U vs. standard aluminium or timber window frames are very little when you consider the longevity of the PVC-U systems. Slightly more expensive at the check out counter but with a much longer life makes the trade off worth it. Often, depending on which supplier you use, the price difference between these three window options is difficult to ascertain. 

PVC-U window frames are also no match for the ever changing climate of New Zealand. Corrosion, pollution, and mould, among other nasty’s, are halted immediately due to the chemical make up of the PVC-U window frame. It really is a wonder as to why the New Zealand market has been so hesitant to adopt technologies that the rest of the world has been taking advantage of for so long.

The smooth surface of PVC-U makes cleaning a breeze, a simple wipe with some cleaning detergent is all that takes to maintain a healthy and sound home. Condensation on the profile of the window frame is non existent due to the thermal frames double glazing and optimum air gap, PVC-U makes those pesky winter days of condensation virtually disappear.

No longer resigned to the margins, sustainable living and building materials have made gains in popularity over the last few years. The mass market appears to be on board in regards to cleaner and greener living in New Zealand. 

And rather than a passing phase, I believe the change has come about due to tried and true products that not only work, but exceed expectations when it comes to overall performance and durability. PVC-U window frames are another welcome example of kiwi society taking another step forward to a sustainable future.

With competitive pricing and benefits that far out weigh the aluminium and timber predecessors, it pays to see how PVC-U could benefit your home. 

Showing 2 Comments

Posted by steve johnston on 14/03/2018 01:10 PM

We have uPVC window frames, the best thing ever.

The sooner NZ moves away from metal frames the better and the more healthy our homes will be. BUT, like all things the windows have to be matched to central heating and high RV insulation to get the best from all the parts. We retrofitted water radiators uPVC frames and new wall / roof insulation to our home. Not cheap, but still cheaper than a new build.

Posted by Mike Clarke on 28/12/2015 08:33 AM

Nice to know that PVC-U is no match for NZ's ever changing climate. Ethylene also comes from oil, which is the most likely source of PVC-U

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