Aluminium vs uPVC Joinery

How does the most popular material for windows in New Zealand measure up to uPVC? 

Aluminium can do some things that uPVC cannot, however there are several important things that uPVC can do better. An honest comparison on aspects such as thermal performance, noise reduction, cost, and look point towards uPVC as the best option for joinery in your NZ home.

uPVC

• Recent testing in Australasia has confirmed that Aluplast uPVC joinery reduces noise transmission by up to 35dB.
• This means that the noise of Auckland city can be almost totally eliminated from your home.

Aluminium

• Noise reduction comes from the type of glass used, the metal frame itself conducts noise.
• Thermal breaking reduces but does not eliminate this conduction.

Thermal performance

uPVC

• The most thermally efficient joinery on the market. The plastic combined with internal air chamber technology mean no heat or cold can travel through the frame
• As a result, condensation does not form on the frame. As long as your home has adequate ventilation, condensation also will no form on the double glazing
• R value of 0.41. Can be increased to 0.84 with Low E glass and argon gas
  Double glazed glass as standard
• 100% watertight and airtight. A double rubber gasket ensures this. If air or water somehow make their way through the first seal, they’re always stopped by the second. A drainage system also ensures that there’s a way out for this air/water.

Aluminium

• The least thermally efficient joinery on the market. Aluminium is a very conductive metal that allows heat and cold to travel through it easily. So even when combined with double glazing, the outside temperature is still able to reach inside of your home.
• This conductivity is what causes the condensation that is a common problem with this joinery.
• Older single glazed aluminium is upgradable as double glazing can be retrofitted.
• Thermally broken aluminium performs well, however the internal rubber is merely reducing conductivity, not preventing it.
• R-value of 0.26, 0.31 if thermally broken.
• Is very watertight and airtight.

Noise Reduction

uPVC

• Recent testing in Australasia has confirmed that Aluplast uPVC joinery reduces noise transmission by up to 35dB.
• This means that the noise of Auckland city can be almost totally eliminated from your home.

Aluminium

• Noise reduction comes from the type of glass used, the metal frame itself conducts noise.
• Thermal breaking reduces but does not eliminate this conduction.

Lifespan

uPVC

• Lasts 40+ years with no corrosion or warping, with minimal maintenance
  15 year guarantee from BRANZ on the uPVC, 10 years on the glass, 5 years on handles and hardware.
• Treated with titanium dioxide to reflect UV rays.
• Steel internal structure to provide strength and rigidity.

Aluminium

• Shorter lifespan. Pitting and corrosion are a common issue, as well as the corners of frames pulling apart over time (the mitres).
• Reduced security, as the rubber seal is easy to pull out so glass can be removed from the outside.

Appearance

uPVC

• Adaptable look means uPVC fits any type of home, including character builds, renovations, and new builds.
• Limited range of window shapes, as uPVC is harder to manufacture and shape than aluminium.
• Bulky profile is not always the right look for certain projects. The large size is necessary to house all the thermal technology.
• Limited range of colours. White is the standard colour in NZ, although many other colours are available. However, these must be special ordered from Germany at a higher price with a 3-6 month lead time.

Aluminium

• Great look. It has a slim profile, large colour range, and can be made into most shapes.
• Great for modern new builds with bold concepts.
• Does not often fit the look of older character homes.

Source: Eco Auckland Blog