standard window sill height australia

There isn’t a single mandated “standard” window sill height in Australia, but convention does the heavy lifting. In most living and bedroom areas, sills commonly land around 900–1050 mm above finished floor level; over kitchen benches they’re typically 1000–1050 mm to clear a 900 mm bench and splashback. Now, the National Construction Code gets serious about fall prevention: if the drop outside is over 2 m and the openable part of a bedroom window is below 1.7 m from the floor, you must restrict the opening to 125 mm or fit a secure screen. A fixed barrier works too, but it needs a top at least 865 mm above the floor—because gravity isn’t negotiable. Treat those figures as design guides, not gospel. Consult official documentation for exact figures.