ISO 18523-2:2018 specifies the formats to present the schedule and conditions of zone and space usage (referred to as input data of energy calculations) for residential buildings.

The schedule and conditions include schedules of occupancy, operation of technical building systems, ventilation rates, hot water usage, usage of appliances and internal heat gains due to occupancy, lighting and appliances. The schedule and conditions for lighting are applicable to fixed installed lighting fixtures.

ISO 18523-2:2018 also gives categories of residential building, zone and space according to differentiating schedule and condition. For residential buildings or its housing units which contain any category of space or zone of non-residential buildings, ISO 18523‑1 applies.

Depending on necessary minuteness of the energy calculation, different levels of schedule and condition from the view point of time and space averaging are specified.

The values and categories for the schedule and condition are included informatively.

NOTE The schedule and condition in this document is basically different from assumptions in order to determine the size of technical building systems in the process of design, where possible largest or smallest values are assumed. Instead, most usual and average values, which are assumed for the building energy calculation, are dealt with in this document.