The influence of albedo of surfaces on microclimatic modifications. New scenarios for Milano

In low energy buildings design, climate conditions become an issue of primary importance to define the strategy and technical solutions. In mild climates, in which both the summer and the winter period show critical aspects, it is important to focus the attention on sustainability in order to decrease energy demand and guarantee thermal comfort. An issue which is only marginally taken into account in building design is the effect that possibly occurred on the microclimatic modifications. Morphology, management of the relation between absorbing, emitting and evaporating surfaces and a careful study of building surfaces could define different boundary conditions for project and planning. If on one hand there is an increasing interest in reflective surfaces to save energy during the summer period, on the other hand it is not uncommon to face the problem of microclimatic modifications and the effect that urban transformation causes on .urban heat island. (constructing large areas, replacing built areas with parks, changing in construction technologies, changing albedo.s surfaces). The aim of this study is to find the impact of natural building envelopes on the urban microclimatic changes in order to evaluate different scenarios in a city like Milano. The investigations were implemented in 2 phases: the first one is focused on the analysis of "green urban skins" technologies and properties. In the second part a short description of the new scenarios is made, pointing out in qualitative terms, the effects of transformation in order to guarantee a reduction of energy demand in summer period. The results of energy balance modelling for today situation and tomorrow scenarios of the city are presented in the last part. Modelling will be done starting from a series of already developed and tested calculation codes currently in use for the assessments of the urban energy balance.