Calculate how many sprinkler heads you need for any room or zone per AS/NZS 2118.1 hazard classification.
For light hazard (offices, schools) under AS/NZS 2118.1, each head covers up to 20 m². A 200 m² zone needs a minimum of 10 heads. Ordinary hazard zones allow up to 12 m² per head, extra hazard only 9 m².
AS/NZS 2118.1 sets maximum centre-to-centre spacing at 4.6 m for light hazard and 4.0 m for ordinary hazard. For ceilings above 3 m, effective coverage area reduces.
Minimum design demand depends on hazard class: light hazard requires at least 60 L/min, ordinary hazard 100–120 L/min, extra hazard 200 L/min. Verify with your network operator as static and residual pressure at the property boundary must meet design requirements.