Energy cost equivalency between demand and supply is evaluated. This metric is exclusive to net zero energy cost buildings. Energy costs to be offset are for energy supplied at site only and is dependent on the applicable utility tariff rates.

Energy cost is an easily measurable and verifiable metric which does not require complex source or emission conversion factors. Integration of demand response controls is also encouraged by using this metric. Lower demand will reduce tariff rates and translate into lower energy costs on the demand side. Energy cost metric is tougher to use with commercial buildings as their tariff rates are higher.

This metric can only be applied if net-metering policies and feed-in-tariff policies are effectively implemented. These policies are under the preview of state governments in India. Tamil Nadu, Karnataka, Andhra Pradesh, West Bengal and Uttarakhand have implemented net metering and several other states are in the process of adopting it. Feed in tariff policies are effective in most states with abundant solar or wind resources. Demand and supply tariff structures also need to be stable.