From urban standards to ecosystem services. An essential semantic change

The implementation of techniques and criteria to provide cities with spaces able to introduce natural elements within urban tissues represents a challenge which modern urban planning has always been faced. In Italy, the scientific and cultural debate on the improvement of the National Law on Urban Planning (1150/1942), which no attention focused on these spaces at all, led to the approval of Law 765/1967 and Interministerial Decree 1444/1968. This legislation introduced into Italian law the concept of “urban standards”, meant as public spaces to be provided in every municipal area, according to a merely quantitative criterion (per capita m2 of space) provided by the law itself, to be calculated during the drafting of Land Use Municipal Plans. Fifty years after these laws came into effect, there is an urgent need for a radical semantic change that allows the transition from the urban standards exclusively quantitative approach to the systemic, transcalar and contextualized one required by Ecosystem Services, a new vision of natural spaces introduced by Millennium Ecosystem Assessment in 2005. The paper will outline the evolution of urban standards from their legislative genesis to the present days, highlighting the reasons why it is essential to promote an upgrade of urban planning legislation, methods and tools, in order to valorize ecosystem services performances, mainly taking into account their location, quality and multiple utility. Finally, a case study will be presented, exemplifying the use of ecosystem services at the urban scale