For health and safety reasons an unflued gas heater must be installed with a permanent ceiling and wall vent to allow for sufficient air changes to be made per hour to keep the occupants air quality safe.
The ceiling and wall vents are appropriate sized to allow the room to be adequately ventilated, which means the infiltration rate for a unflued gas heater is greater / higher than a convention ceiling or wall vent allowing a great gain of heat gains or heat loss throughout the year. The following shows how to select an unflued gas heater for a specific zone.
If the plans show a capped gas point, the assessor can safety assume the gas point will be flued to outside air as a capped gas point would not trigger the designer to add the mandatory ceiling and wall vents.
If the plans show a gas point which is not detailed as capped, request further information so the assessment can be completed correctly.