Setback (Building Margin)

A setback is the minimum mandatory open distance that must be left between the building's outer face and the plot boundary, on the front, sides and rear. Setbacks ensure light, ventilation, fire-tender access, privacy and future road-widening reservation. They are prescribed by the local Development Control Regulations and scale with building height and plot size — taller buildings need larger setbacks (the 'open space' rule).

For low-rise plots a typical residential pattern is 3.0-4.5 m front and 1.5-3.0 m sides/rear; for high-rises the side/rear margin may be 6-16 m or more, often expressed as a fraction of building height. NBC 2016 Part 3 sets the framework for open spaces, means of access and fire-tender movement; the binding figures come from the city bye-laws. Building within a setback is a common cause of Occupation Certificate rejection.