Current fire safety regulations in historical buildings are generally limited to the number and dimension of exits and evacuation paths. This approach clearly clashes with preservation criteria because of the need of invasive layout modifications. On the contrary, a “behavioural design” approach could solve this conflict by proposing evacuation facilities based on effective human behaviours. This work proposes an innovative wayfinding system based on phtoluminescent continuous signs. Experiments in a significant real world scenario demonstrate the possibility to considerably decrease the evacuation timing without building layout modifications.