Lighting is for people so that they can see and be productive. It follows, then, that lighting system improvements that increase worker productivity can yield a high return on investment. Consider, for instance, the cost associated with an employee. Assume that the direct costs of the employee, including wages, taxes and benefits, are $60,000 per year. This means that the employee is paid almost $29 per hour, based on 40 hours per week and 52 weeks per year. Normal lost time due to holidays, vacations and sick time are part of the benefits.

A typical office worker requires about 100sqft of dedicated space, mostly actual work area and access to it. Modern lighting systems consuming energy at the rate of 1.0 W/sqft or less, operating 3,500 hours per year (work time plus cleaning and other non-working hours) cost about $40 per worker per year to operate, including energy and maintenance. The annualized owning cost for a typical office lighting system costing about $2.50 per square foot is about $30 per year. In other words, the total cost of owning and operating the lighting system is about $70 per employee per year, or the same as about 2.1 hours of employee labor cost, or about 1/10 of 1% of annual productive work hours.

Based on these values, an improvement to an ordinary lighting system that increases employee productivity is very quickly amortized. A 1% improvement in productivity throughout the year would realize a benefit to the employer worth $600 (0.01 x $60,000). Investing $600 per employee in improved lighting, if it provided that small increase in productivity, would produce a 100% return on investment forever. A more modest investment of about $300 per employee would return 200% forever. For reference, a first-quality office chair costs $600-$900. The potential return on investment is substantial for well-designed lighting systems.

But there are also savings to be had from lighting systems which use less energy. How should productivity be maintained or even enhanced while reducing lighting energy use? In new systems, there are a variety of options including enhanced daylighting. For existing installations, doubling the cost of a typical lighting system retrofit enables the addition of dimming or other controls and an opportunity to utilize better performing and more attractive design options that minimize bad lighting.