Will a window lock stop me opening the window?

The window has to open again: what the code requires

The release is allowed, and it is also conditioned. The code allows a device to be overridden for a fire or another emergency, and where it can be, the unlocking device “must be child resistant.” Child resistance is not a vague quality: “Child resistance could be achieved through the use of a tool, key or two hands.” And where the window is to open fully past 125 mm, the code’s answer is that the release mechanism joins the 250 N requirement rather than replacing it: “D3D29(3) in addition prescribes that an 865 mm barrier (sill) would be required.” A wall beneath the openable window can serve as that barrier, in the code’s own words, “if the criteria in D3D29(4) are met,” so the release, the force figure and the barrier read together as one rule.

New South Wales writes the same requirements into the device itself, as three conditions: the opening restricted so a sphere of 125 millimetres or more cannot get through; 250 newtons of outward horizontal push resisted; and a child resistant release mechanism wherever the device can be removed, overridden or unlocked. The second leg of the rule is the one a cleaner meets with their hands: a device that releases is not a defect; it is the half of the design that lets the window open fully, and the child resistance is what keeps that half from being a child’s way out. Sliding windows have their own, older answer in the code: “Sliding window locks may lock a sash so a 125 mm sphere cannot pass through.”

The hardware, as the state’s product guide describes it

NSW Health’s window safety product guide walks through the devices a household can buy, and its captions describe the release plainly. One restrictor, in its words, is opened by unlocking with the key and disengaging the restrictor from the window; a second is unlocked by a key as well. A guard comes with release buttons, which “allow for quick removal of guard in an emergency.” A safety net is hooked on to an anchorage fixed around the whole window frame, and the product guide’s note is the reassurance a parent needs: “Adults can remove netting from anchorage system.”

Two practical notes come from the same material. A restrictor can be mounted so the window stops at 12.5 cm, which is the number the product descriptions use for the sphere rule. And the hardware itself is ordinary: the guide finds it at hardware stores and lock suppliers, which matters for the question this guide opened with, because it means the release is a product feature rather than a workaround.

No Australian Standard: what that means at the shop

The most useful warning on the subject is one NSW Health prints about the products themselves: “there is no Australian Standard for Window Fall Prevention Devices,” so “Australian products are tested against a variety of international standards with a minimum load testing of 333N as required by the American Standard Specification for Window Fall Prevention Devices.” The advice that follows is the one to carry into a purchase, in the guide’s own words: “Check that any window safety product you purchase has been subjected to load testing,” because that testing is what ensures the device can stop a child who falls against the window from falling out. Read beside the two laws’ own 250 N figure, it is a case where the code’s minimum and the products’ testing practice are worth comparing before the money is spent.

Who installs it, and who is told

For a window in a NSW strata scheme, the device arrives with one more piece of process. Window locks are paid for by the owners corporation unless the by-laws agree otherwise, and the committee can generally arrange the purchase or the installation from the administrative fund. If an owner installs a device themselves under the state’s window safety law, the owners corporation has to hear about it in writing within 7 days. And the surface the device sits on has its own owner, decided the way guide 1 sets out: in NSW, which by-law governs the scheme decides whose the exterior glass is, and the model by-laws give the corporation the exterior surfaces that “cannot be accessed by the owner or occupier of the lot safely or at all.” The lock is the corporation’s to pay for, the glass can be the occupier’s to clean, and the release mechanism is what keeps both duties from colliding: a cleaner unlocks with the key and disengages the restrictor to open the window, as the product guide describes it.