Calculate waste diversion rate, landfill percentage and estimated CO₂e savings from your waste audit data.
Enter total waste generated and the amount diverted from landfill.
Diversion Rate = Diverted ÷ Total × 100%. CO₂e saving estimated at 0.5 t per tonne diverted (mixed waste). Actual saving depends on material type and processing method.
Waste diversion rate is the percentage of total waste generated that is diverted away from landfill through recycling, composting, reuse or energy recovery. A diversion rate of 70% means 70% of waste is recovered and only 30% goes to landfill. NZ's national diversion rate for construction and demolition waste is around 55–65%.
Green Star NZ projects typically target 70–80% diversion from landfill. Auckland Council's construction waste minimisation policy encourages contractors to achieve at least 70% diversion. Best-practice projects managing waste streams well (sorting concrete, steel, timber, cardboard separately) often achieve 85%+.
Document total waste generated and diverted with weight-based records from certified weighbridges or skip hire receipts. Keep records by waste stream (concrete, steel, timber, general) and by disposal method (recycled, composted, landfill). Green Star MW-01 (Waste) credit requires tonnage data and chain-of-custody documentation from waste processors.