Final answer:
The vertical clearance above the cooking tops of free-standing or built-in ranges to combustible material should be at least 30 inches to prevent fire hazards and allow for proper ventilation.
Step-by-step explanation:
In terms of engineering standards, free-standing or built-in ranges should have a vertical clearance above the cooking tops of at least 30 inches to combustible material.
This clearance is necessary to prevent any potential fire hazards and allow for proper ventilation during cooking.
Having this vertical clearance ensures that there is enough space for heat to dissipate and reduces the risk of heat damage to surrounding materials.