The purpose of the publication is to provide lighting practitioners with a method (decision scheme) to determine the lighting requirements for indoor spaces. The decision scheme is intended to be based on a set of variables that go beyond the type of activity to be performed and include the most relevant influencing factors, such as visual task characteristics, personal variables, and contextual variables.
The definition of a decision scheme to tailor the design values based on aspects that could modify the lighting needs is in line with the approaches recently adopted in other guidelines and standards (eg. EN 12464-1:2021, ISO 8995-1 and several IES lighting application standards/tools) and would support further developments of such approaches.