Energy efficiency has become a key objective in the current context of increasing energy demand, decreasing resources and global warming. Key to efficient energy savings, however, are users' awareness and behaviour.

A new Directive, dubbed the energy performance of buildings Directive (EPBD), brings the new concept of net -zero energy buildings (NZEB) meaning buildings with a zero energy balance that have a better level of energy performance than the standard energy efficiency requirements in current building codes.

In 2006 the Technical Building Code (CTE) has come into force in Spain. The Code provides for a reduction of energy demand of buildings from architectural design and a reduction of conventional energy consumption through the use of solar thermal water to produce heating and photovoltaic panels to generate electricity.

Reducing the energy requirements of buildings is an absolute priority in Europe. The energy demonstration project SARA has developed several public-access eco-buildings in France, Italy, Slovenia, Spain, UK and Uzbekistan.