Properly installed office lighting should provide an appropriate amount of light for the comfortable and safe completion of office-based tasks. Good lighting is properly directed and free of annoying glare. Poor lighting causes headaches, blurred vision and upper body aches and pains due to incorrect posture at poorly lit work stations. Ambient light from computer monitors has compounded the problem of providing adequate lighting for the in-home or distant office.
The intensity of light, or illuminance, is measured in lux. Outdoor light on a clear day provides approximately 10,000 lux. Inside the home or in an office building, lighting close to a window measures about 1,000 lux, while an interior room or space may be lit by as little as 25 lux. Supplemental lighting is required to provide adequate lighting for the tasks being performed in the office space.
Light Engineering Specifications
When an office building is designed, building services engineers analyse the space and how it will be used in an effort to provide adequate lighting for the workers within. The Chartered Institute of Building Service Engineers produces a Code for interior Lighting which outlines lighting requirements. For example, general offices, where visual tasks are moderately difficult, require 500 lux, while a design or architectural office engaging in detailed drawing may require 750 lux.
Lighting Related to Tasks
Several areas within the office may require more or less light, depending upon how each area is used. Filing and copying can be comfortably done at 300 lux, whereas data processing requires 500 lux. The detailed work involved in technical drawing boosts the illuminance level required to 750 lux.
Glare on a computer monitor causes low contrast screen display. Mechanical and drawing work requires long-term concentration on very small components. In these situations, good lighting is a must. When employees are required to perform such tasks for long periods of time, the office illuminance should be boosted to between 2,000 and 5,000 lux.