Installing sub-meters for each department (D) is the most equitable way to ensure accurate and fair

distribution of electrical costs. Sub-metering provides real-time, precise measurement of energy

consumption by each department, ensuring that they are only charged for what they actually use.

Advantages of sub-metering (D):

Encourages accountability and energy conservation.

Ensures fair and accurate billing.

Allows facility managers to monitor and optimize energy use.

Comparison with Other Options:

Net area occupied (A): Does not account for actual energy consumption—departments with energy-

intensive equipment would be unfairly subsidized by those with lower usage.

Negotiating chargeback rates (B): Creates inconsistency and potential disputes; lacks transparency.

Headcount-based charging (C): Fails to consider that energy usage varies based on equipment, not

just the number of people.

Reference: ISO 41001:2018 Facility Management, Strategic Facilities Management by RICS​