Emergency and Exit Lighting Requirements

What You Need to Know

Every building needs a way out when the lights go off. Emergency lighting and exit signs guide people to safety during a power failure or fire. AS 2293 sets the design rules. NCC 2025 Part E4 tells you which buildings need it. The system must turn on within seconds, last at least 90 minutes, and light the escape path to at least 0.2 lux at floor level. Get this wrong and the building will not receive an occupation certificate.

• Emergency lighting must provide at least 0.2 lux on the centreline of every escape path at floor level (AS 2293.1, Cl 3.3)
• The average illuminance across the path must reach at least 0.5 lux (AS 2293.1, Cl 3.3)
• Stairways need at least 1 lux on each step (AS 2293.1, Cl 3.3)
• The brightest-to-darkest ratio must not exceed 40:1 anywhere on the escape path (AS 2293.1, Cl 3.3)
• The system must reach 10% output within 1 second, 80% within 15 seconds, and full output within 60 seconds (NCC E4V1)
• Battery duration must be at least 90 minutes from full charge (AS 2293.1)
• Exit signs must be mounted 2.0 m to 2.7 m above floor level (AS 2293.1, Cl 4.7)
• Exit signs must be visible at all times when the building is occupied (NCC E4D5)

Picture a three-storey Class 5 office building with 400 m² floor plates. Every storey exceeds 300 m², so NCC E4D2 triggers emergency lighting throughout. You need luminaires along every corridor, inside every fire-isolated stairway, and at every change in direction.

Start with the stairways. Each step needs 1 lux, which is five times the corridor minimum. A single luminaire at the top of a flight will not cut it. You will typically need one fitting per landing and one mid-flight to hit the numbers.

For corridors, the spacing tables in AS 2293.1 (Tables E1 to E5) give you maximum distances between fittings based on the luminaire classification and mounting height. A Class D50 fitting mounted at 2.7 m covers roughly 8 m in a 2 m wide corridor. Wider corridors or higher ceilings need closer spacing or higher-rated fittings.

Exit signs go above every door that leads to a required exit, every fire stairway door, and every discharge point to a road or open space. Each sign has a rated viewing distance. A standard sign rated at 24 m works for most corridors. Longer sight lines need a 40 m rated sign or additional signs along the path.

Testing matters. Every six months, the system needs a full 90-minute discharge test. Monthly visual checks confirm no lamps have failed. A logbook must stay on site and records must be kept for 7 years. Missed testing is one of the most common compliance failures found during audits.