Sustainable building, or green building, is a new way of thinking about the practice of construction, based on criteria that keep its environmental compatibility in consideration. This is an increasingly necessary shift given that energy use in residential, commercial and public service buildings currently accounts for 35% of total worldwide energy use.

New buildings can be designed and built with a degree of efficiency up to 70% greater than current levels, with many technologies already on the market and others being developed.

Windows can be built in a way that is three times more efficient than in the past; new conditioners save 30-40% energy over older models; lighting designed with certain criteria can bring savings from 30 to 60%. All home appliances have made major progress with certification of their consumption levels.

It has been demonstrated that, with the same structural conditions (insulating, thermal bridges and so forth), a medium-sized dwelling with sanitary hot water and a traditional stand-alone thermal boiler system consumes about 90 kWh/sq. m. yearly, while a dwelling of the same size, with a thermal and sanitary hot water system connected to a district heating grid, consumes about 45 kWh/sq. m. annually.

The introduction of energy certification for buildings in Italy with legislative decree 192/2005 launched a process of changing the way in which public and private buildings were designed and built.

The innovations that came with the provisional standards of the decree have already brought major changes, including the minimal requirements of thermal insulation for the envelope (with two steps in 2006 and 2009), the thermal regulation requirement, the requirement to use thermal solar power to produce sanitary hot water in all newly-built public buildings, and the requirement to set up works of private and public new buildings to place solar technologies on their roofs.

These new regulations, though adding extra cost in the short term, are an opportunity to advance the construction market, provide a diversification of its products in environmental terms and reinforce its strategic position over competition.

For more information, see the Inergia-Santarelli presentation at the conference ISES 2005.