A ventilation space is a cavity serving a ventilation role within a selected construction. For a roof, identify the space concerned and its relationship with other layers. Not every visible void is automatically an effective ventilation provision within the actual assembly.
Changes to insulation, eaves or the ridge may raise questions about those relationships. Ask which existing provisions remain and how the proposed solution connects with them. A general instruction to ventilate is insufficient to describe the arrangement of the entire roof.
This explanation provides no opening size or calculated airflow. Appropriate assessment depends on the actual system. Document investigation and its limitations so later work does not unintentionally rely on a space whose function or continuity was never established in the first place.
Worth asking
Frequently asked questions
Is every void a ventilation space?
No. Function and relationships need to follow from the actual assembly.
Does the planner calculate ventilation?
No. It creates only a preparation summary without technical sizing.