The minimum clearance requirements for overhead conductors depend on their voltage class and what they are hanging over. Note that engineering considerations and intended use might make higher minimums legally obligatory. If in doubt, make more space.
If the conductors are not over buildings, they must meet one of five enumerated clearances and voltage limits. For example, over residential property and driveways the clearance is 12 ft if the voltage is 300V or less (higher voltage m