What should be height for perfect lumen output for parking light?

The toughest part of the light design is to decide the output level of lumens for parking light. If we have low lumen output, then you may have an unsafe area. For Parking light, the mounting height should be in the range of 12 ft. to 20 ft. and in some cases can reach up to 35 ft.

The spacing between parking lights depends on the mounting height, the higher the fixture the fewer the poles needed to light an equivalent area. Consideration of the lumen output of the parking lot fixture should be when the height and spacing are finalized.  Go brighter and higher if you want your space more inviting.   If you go up to 30 feet and do 2 light heads at 30,000 or 40,000 each, you can space the poles 30-40 feet apart.