The text considers the role of residual outdoor spaces in the construction of planning in the Milan urban area. The thesis presented is that it is possible today to equip the Milan metropolitan area with new structural forms able to address complexity in a dimension of the whole by planning residual space, that huge and very varied quantity of outdoor spaces that can be surveyed and classifi ed as ‘residual’. More specifi cally, the paper discusses two types of consideration. The fi rst regards those processes of which the ‘residual’ is the outcome. The second addresses the subject of forestation, defi ned as a horizon of meaning for planning outdoor space capable of grafting onto transformations in progress in the area.
Keywords: Milan; residual spaces; forestation