High energy efficient buildings: sustainable strategies based on Structure / Envelope techniques with artificial thermal inertia.

The big amount of energy requested by buildings has shown the necessity of proposing new technologies in building construction and services. Saving energy has become a primary issue nowadays. An integration during the design phase among Architecture, Building Technology and Services, is very recommended in order to obtain a more sophisticated “living-environment” using relatively simple strategies avoiding extra-costs. Industrialized systems of construction, based on assembled stratified layers over a bearing frame structure, seem to offer a lot of advantages in a sustainable approach. Through the exploitation of renewable sources and the optimization of the building thermal behavior it is possible to reduce considerably the energy consumption. Thermal inertia appears to be one of the fundamental characteristics of buildings (combined to high levels of thermal insulation). New materials can be investigated to enhance the performances of lightweight building systems. Among these, PCM (Phase Change Materials) can be integrated into lightweight building components, providing an artificial inertial effect. They can be used for storing heat during winter days and releasing energy during the night, reducing overheating risks in summer, especially in Structure / Envelope constructions (S/E) and storing off-peak energy in order to have a warm/cool surface that contributes to irradiative comfort by day. An extensive experimental campaign was set up to understand the potential for integration of hydrated salt PCM’s in lightweight floors and internal partitions. Some recent examples are shown to underline the possible strategies and their effective results. The residential projects illustrated demonstrate how to design high energy efficient buildings using ordinary technology and performing a pleasant contemporary architecture: sustainable buildings don’t mean to be aesthetically unsustainable.