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How does uPVC compare?

uPVC vs Aluminium

You may wonder why you should choose uPVC for your doors and windows rather than aluminium?

uPVC is a great material to use in your house as a joinery solution. However, there are several key differences between the materials, particularly in terms of performance, cost and look. Here is a break-down of the pros and cons of both, so you can make an informed decision.

uPVC Pros

High performance

  • Most thermally efficient, keeping you warm in winter and cool in summer
  • High sound resistance, blocks out street noise up to 34dB reduction
  • Can eliminate most condensation – depends on sources within your home
  • Watertight and airtight

Life span

  • Lasts 40+ years, with no fading, corrosion, warping, and with minimal maintenance

Perfect for Wellington wind

  • Most joinery is rated to SED wind zones for 216kph wind

Strong structure

  • Solid looking product
  • Internal steel for strength and load bearing
  • Welded corners

Double Glazing

  • Double glazed as standard
  • Glazing thickness 23mm standard, out to 31mm and 41m with some frames
    Handles a variety of glass types , like Obscure, Laminated and Low E

Adaptable look

  • Fits any type of home, including character builds

R Value

  • Standard R value of .41
  • Viridian planitherm XN Low E Glass increases that to r.84

Used throughout the world as a joinery solution of choice


  • Recycled in Europe into new windows and doors

Aluminium Pros

Great look

  • Slim profile
  • Large colour range and colour matching
  • Easily formed into designer shapes, therefore fitting well into modern architecturally designed buildings

Affordable price

  • Standard aluminium is cheaper than uPVC. Thermally broken aluminium is similar in price.

Easy to install

  • As it has high installation tolerances


  • Old aluminium can be retrofitted with double glazing

uPVC Cons

Large size

  • uPVC frames are typically a larger profile in order to fit in all the technology that makes it so thermally efficient

Limited range of colours

  • The main colour used in New Zealand is white, although other colours are available at a higher price with a 3-6 month lead time as they must be specially imported.

The above two cons mean that the look of uPVC may not be right for certain projects

Limited range of window shapes

  • PVC is harder to manufacture than aluminium, therefore harder to make into unique shapes

Not as well known in the market place by consumers or architects

Bad reputation in some quarters based on early attempts to introduce to the NZ market place

Aluminium Cons

Low performance

  • No thermal efficiency, meaning the cold and heat transfer easily through the joinery, making the frames either hot or cold to touch, depending on the outside weather
  • Condensation forms easily on frames and glass
  • Transmits noise easily

Short life span

  • Pitting and corrosion are an issue
  • Colour fade
  • Corners of frames (mitres) often pull apart over time.

Reduced security

  • Easy to pull rubber out and remove the glass from the outside

Look does not fit the character of older houses


  • Old Aluminium typically around r.16
    Newer thermally broken aluminium around r.25