The special circumstances of the high accident rate in the construction industry compared to other sectors are significant and represent a major concern for many countries. Construction work involves a large number of risks that cause or may cause accidents with serious consequences for the worker's health, even death. The Level of Preventive Action is a novel methodology of occupational risk assessment adapted to building works. It is based on the development of the mathematical formulation of William T. Fine's method. Its implementation covers four of the techniques for combating risk: Safety at Work, Industrial Hygiene, Ergonomics and Psychosociology. It evaluates, quantitatively, the amount of preventive action required based on the characteristic complexity of the work units, their location and their interdependence. The method protocol defines a new observation parameter called Characteristic Value which is inherent to the real situation of the construction process. The aim of this study is to develop the characterisation of the Characteristic Value in the Level of Preventive Action method. It also justifies the procedure to obtain this Characteristic Value and how its implementation and result should be interpreted. Finally, the methodology is applied on a real case.
Keywords: characteristic value; construction; health and safety; preventive environment; risks assessment.