Window frames


Window frames can be made from aluminium, timber, uPVC, fibreglass, or a combination of these materials. Each offers different performance advantages in terms of durability, maintenance and energy efficiency.


Manufacturers will often specialise in one or two frame materials, it’s worth taking the time to find out about the pros and cons of all your options.

Although one window frame may offer significant benefits in one particular area, it may be at the expense of a feature better suited to your home window needs.

View the snapshot table below for a quick review of the common framing materials or compare each frame in more detail.


Snapshot of common window frames

Cost Maintenance needs Energy efficiency Durability
Aluminium Low Very low Poor
(can be improved with a thermal break)
Timber High High Very good Poor (if not maintained correctly)
uPVC High Low Very good Very good
Composite (aluminium & timber) High Low Good Good
Fibreglass High Very low Very good Very good
*comparative to equivalent size and glass specification *ability of the frame to insulate against the transfer of heat

Aluminium window frames

  • Economical
  • Durable
  • Low maintenance
  • May allow heat transfer without thermal break
  • Susceptible to condensation
Timber window frames

Timber windows

  • Aesthetically pleasing
  • Great thermal performance
  • Not as durable as other frames
  • Requires a bit of maintenance
uPVC windows

uPVC windows

  • Long term durability
  • Great thermal performance
  • Limited colour range
  • Darker colours fade over time
Composite windows

Composite windows

  • Interior colour flexibility
  • Good thermal performance
  • Low maintenance for aluminium component
  • Can be expensive

Fibreglass windows

  • Great energy efficiency
  • Structurally strong
  • Limited options
  • Can be expensive