In industrial areas the heritage issue takes on a peculiar significance since it is impossible to single out one elementthat must be preserved at the expense of others; by contrast, the multiple and heterogeneous components of the industrialcity transformed by social and productive practices developed over time, relate inseparably forming a complextissue. In this case, the analysis of the Ile de Nantes project demonstrates the importance of valuing these industrialfabrics and keeping the links between urban planning and preservation of industrial heritage.