Window installation tips

Installing windows

Although most consumers will never personally install a window, there are checks that can be undertaken to ensure your windows are fitted properly. Poorly installed windows can result in problems such as uncontrolled airflow through hidden gaps and cracks.

To achieve maximum performance and ensure a proper seal, it is recommended windows are installed following the manufacturer’s instructions. This is particularly important for windows and doors designed specifically for acoustics and energy efficiency. Permanent damage is possible if care is not taken.

Alongside manufacturer guidelines there are a number of window installation tips you or your builder can follow to make sure your windows are installed correctly.




  • Keep sashes closed while installing frames.
  • Keep sills level and fully supported during installation.
  • Test that sashes open correctly before permanently fixing them.
  • Leave name plates, part numbers and rating labels on products for future reference. A permanent performance label is a requirement for all for windows in all states and territories of Australia.
  • Protect glass from harmful construction dust. Cover windows or clean regularly during construction or renovation.
  • Remove cement mortar and plaster droppings from windows immediately.
  • Take extra care when cleaning high performance glass (e.g. low emissivity glass).
  • Hose down brickwork to remove residual cleaning acid which may leach out and cause damage.
  • Keep sliding windows and door tracks clear of sand and cement droppings.
  • Install temporary screens if welding, sandblasting, floor sanding, cutting or other potentially damaging construction practices are used near glass.



  • Never stand on the windows or doors, or use them as a support for scaffolding.
  • Don’t slide material through the frame during construction.
  • Never use acid to remove mortar stains on window frames.


Common mistakes

Problem Action
Window fitted inside out All new windows are sold with stickers to indicate which side should be fitted on the outside. Once fitted check the sticker to validate correct placement
Poor fit to inside wall Inspect window installation before surrounding walls are erected to ensure mistakes are not hidden
Poor fit to insulation Inspect window installation before surrounding walls are erected to ensure mistakes are not hidden
Windows do not open or close properly Check for smooth operation at the time window is installed
Incorrect windows have been installed Clearly specify frame and glass names on all building plans. When installed ask for evidence from your builder or window installer