Window openings 125mm

@Sue S said:
does anyone understand the new laws on restricting window openings to 125mm in all floors above ground level?  Are keyed locks sufficient, or do they need to be unopenable?  

As long as the keys or locks are properly “child resistant” you are OK

THIS GUIDE from the Australian Building Ccdes Board  explains the rules in considerable detail, and says this:

The BCA (Building Code of Australia) allows a screen or window opening restricting device which protects an openable window to be installed in a manner that allows it to be removed, unlocked or overridden. This would be useful, for example, in the event of a fire or other emergency or to allow for cleaning. In these situations, the unlocking device must be child resistant.

It goes on to describe a child-resistant restraint thus:

lA child resistant release mechanism could include a device which requires a key to unlock; a coordinated two handed operation to release; or the use of a tool such as a screwdriver, spanner, or allen key to remove the screen or shift the window to the fully open position.