Workplane height is the height of the surface where light is assessed.
Workplane height is the height of the surface being assessed, such as a bench, desk, floor route or shelf face. It changes effective height for beam and spacing estimates.
Technical meaning
Workplane height names the vertical position of the assessed surface.
It can be floor level for circulation, benchtop height for kitchen work, desk height for office tasks or shelf-face height for vertical checks.
Mounting height and workplane heightBeam and lux geometry should name the assessed plane before using height in a calculation.
Calculation use
Effective height is mounting height minus workplane height.
Changing the workplane height changes beam diameter, spacing interpretation and the surface where illuminance should be discussed.
Not the same as
Workplane height is not always floor height. Many useful lighting checks happen above the floor.
Workplane height is not a lux value. It defines where the value is meant to be assessed.
Australian context
Australian lighting records should state the assessed plane so room, workplace and downlight estimates can be read without guessing the surface.
Examples
Example
Value
Planning note
Kitchen bench
about 0.9 m
Effective height is reduced compared with a floor-plane check.
Office desk
about 0.75 m
Desk tasks and screen glare should be recorded separately from floor circulation.
Floor route
0 m
Used for movement, parking bays and circulation checks.