Three steps. The space, the recommendation, and a quote request that lands with the sales desk, with a reference number.
Fixtures = (target foot-candles x area) / (fixture lumens x coefficient of utilization x light loss factor).
The planner uses a coefficient of 0.65 indoors and 0.55 outdoors and a light loss factor of 0.85, which is deliberately conservative: a design that ignores light loss is under-lit inside two years. It checks the spacing-to-height ratio and steps up a lumen package if the fixtures land closer than 0.7 times the mounting height.
Energy savings compare the system watts of what is there today, ballast included, against the recommended fixture one for one, at the blended commercial rate for your province. Metal halide is converted on lumens, never watts, which is the mistake that under-lights a lot.
Targets are IES-based guidance and provincial rates are estimates. A photometric layout and a written quote confirm everything before an order.