There are actually 5 louvre sizes to choose from:

  • 47mm
  • 64mm
  • 76mm
  • 89mm
  • 114mm

This is the measurement across the width of the louvre blade.

The smaller sizes are very outdated, so we can easily narrow this down to just two recommended sizes, the medium 76mm and large 89mm louvre. Either size looks great, but there are few things that may affect the size you pick.

Size does matters

Like the design and colour, the louvre size will also affect the light entering the room, so the larger you go the more light you will have.

Larger windows and doors certainly lend themselves to the large 89mm louvre. Most door shutters end up as large single panels, and smaller louvres will look out of proportion in a wide panel.

Top and bottom rail heights

Most customers don’t realise that the louvre size also affects the width of the top and bottom rails. These rails hold the shutter together. The width of the rail is determined by the window height and louvre width, as there are only a limited number of louvres that can fit within a certain height range.

Here is are two examples with different window heights:

A window height of 1140mm

  • 76mm = 14 x louvres, and 100mm rails.
  • 89mm = 12 x louvres, and 87mm rails.

A window 1185mm height

  • 76mm = 15 x louvres, and 92mm rails.
  • 89mm = 12 x louvres, and 111mm rails.

Most companies won’t mention this, some won’t even know they can check or have these sizes to hand, but we check and monitor these sizes as part of our ordering process, and if the rails look like they are going to be too large, we will get in touch to discuss and offer some solutions.