The use of sensors on lighting systems is commonplace in many Civil Service offices. They provide a very effective automatic solution to reduce energy usage by switching off artificial lighting when there is either sufficient natural daylight or when the space is unoccupied. It has long been the policy of the Office of Public Works to install this equipment in new office developments. It is often not economically feasible to retrofit such equipment into existing lighting installations. However, where other works, such as lighting refurbishment, are undertaken, the investment is usually justified.
It is not practical to estimate the savings already accrued, or indeed the possible savings, if a more targeted campaign in the installation of lighting sensors was undertaken. Savings are dependent on the cost of installation, the type of lighting installed, the occupancy profile of the building and the natural light available. Lighting sensors form one part of the many solutions that are used to minimise energy wastage in public sector buildings. It is the policy of the Office of Public Works to use the technology in all new build and refurbishment installations (where there is practicable reasonable return on the investment). Other more sophisticated lighting control systems are also used, where appropriate.