Child-safe window screens and the NCC openable-window rules

Why window falls matter

Every year young children are hurt in falls from windows and balconies, and most of those falls happen at home. Children under five are most at risk. They climb before they understand height, and to them a fly screen looks solid, even though it can pop out with a little pressure.

That is why the National Construction Code (NCC) includes rules for openable windows in new homes. They have been part of the code since 2013 and now sit in the NCC housing provisions that apply to new homes in Queensland.

What the NCC rules say

The rules apply to new building work, such as a new home, an extension or a new window in a renovation. In simplified terms, there are two situations.

Bedroom windows

A bedroom window needs protection when the floor of the room is 2 metres or more above the surface below the window outside, and the lowest part of the window opening is less than 1.7 metres above the bedroom floor. In practice, that covers most openable windows in upstairs bedrooms, and some ground-floor bedrooms on sloping blocks.

Other rooms

For rooms other than bedrooms, the trigger is higher. Protection is needed when the floor is 4 metres or more above the surface below, and the lowest part of the window opening is less than 865 mm above the floor. Here the protection works as a barrier at least 865 mm high: it must not let a 125 mm sphere pass through, and it must not have rails or footholds between 150 mm and 760 mm above the floor that a child could climb.

These are simplified summaries. The exact wording, how each height is measured and any exceptions are set out in the NCC, so ask your builder or building certifier what applies to a particular window.

Restrictor or screen: the two ways to comply

For bedroom windows, the code allows two approaches. The first is a device that limits how far the window opens, such as a restrictor on an awning window's winder or a stop on a sliding sash. The second is a screen with secure fittings that covers the openable part of the window.

Either way, the device or screen must pass the same tests. It must not let a 125 mm sphere pass through the opening or the screen, it must resist an outward horizontal force of 250 newtons, and if it can be removed, unlocked or overridden, its release must be child resistant.

Why restrictors are common

Restrictors are cheap and simple, so many builders use them. The catch is that a window held to a gap of less than 125 mm lets in very little breeze. On hot nights, owners often override them, which removes the protection completely.

Why a screen is often the better answer

A screen that meets the requirements lets the window open all the way, so you get the full breeze through the room and the protection stays in place. A security screen built to AS 5039 has been tested against far tougher attacks than a child leaning on it, and its frame is fixed so it cannot simply be pushed out of the opening.

Why a fly screen is not enough

A standard fly screen is made to keep insects out. Its fibreglass or aluminium mesh tears easily, and the frame is held in by small clips or springs so it can be removed for cleaning. A child pushing or leaning against it can push it straight out of the window. Fly screens are not designed to stop a fall and should never be relied on to do so.

Balancing safety and escape

A bedroom window can also be a second way out in a fire. Where that matters, an emergency escape screen can be opened from inside without a key, using a release designed to be hard for a small child to operate. Make sure every adult and older child in the house knows how it works.

Older homes, renovations and rentals

The NCC applies to new building work, so an older home does not have to add protection to the windows it already has. If you replace or add a window as part of a renovation, the new window may need to comply, so check with your builder or certifier before you order.

Even where it is not required, the NCC rules are a sensible standard for any home with young children. Kidsafe also recommends keeping beds, cots and furniture away from windows so children cannot climb up to them, and supervising children near open windows and balconies.

Cost and what to expect

As a guide, an openable or child-safe window screen is typically $380 to $750 per window, supplied and installed, depending on the size, the mesh and the type of window. A fixed security screen, which suits sliding windows that open behind it, is typically $290 to $620 per window.

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