Data tab on Model Options dialog.
There are three levels of gains model detail:
Lumped - all internal gains including occupancy, computer, office equipment, miscellaneous, catering process and lighting gains are lumped together into a single value. Solar gains are still calculated in the usual way.
Early - gains can be defined separately under various categories (see above).
Detailed - gains are specified by defining each individual item of equipment in each zone on the Equipment tab. If you select this option then DesignBuilder will automatically set the Timing model option to Schedules. Note that this option was developed for creating very detailed models of existing buildings based on survey data. Entering this data for a large building is very time-consuming and in most cases you will be better served by the Early gains option above.
Check this option if you wish the timing of internal gains to be the same as occupancy. Unchecking the option allows you to set the timing of each type of gain individually. For example there may be low levels of emergency lighting and some IT equipment usage while the building is unoccupied.