Optimisation models for energy environmental planning based on the concept of economic equilibria share a common flaw that stems from their neoclassic roots: hypothesis of a perfect information and hypothesis of perfect economic rationality. A way to circumvent this issue consists in soft-linking data from sociological surveys that determine technical coefficients for MARKAL model, creating a hybrid approach of coupling a deductive engineering model with typical inductive methods of social sciences. Behavioural changes are described as virtual technologies with usual technology attributes. The method is illustrated on a case of lighting bulbs. The goal of the approach is to build long term policies that are not solely based on technology progress but also taking into account social change.