The price of housing can decrease as a result of proximity to industrial facilities. This effect depends on the perception of risk by the local inhabitants and is therefore potentially modified by events which can change risk perception, for example the prevention plans for technological risks in France. The impact of these plans is difficult to estimate, because those put in place in built-up areas are recent. However, by analysing other events that modify the perception of risk we can put forward some initial suggestions. The three built-up urban areas studied are located close to industrial facilities in three major conurbations in France, in Bordeaux, Dunkerque and Rouen. Usng the hedonic price method we were able to estimate the effect of the proximity of factories on housing prices. Results suggest that differences in price were not affected by local incidents, nor by the AZF disaster, nor by information provision, nor by the introduction of the technological disasters insurance regime.