Experts from 19 countries (Australia, Austria, Belgium, Brazil, Canada; Czech Republic, Germany; Finland, Indonesia, Italy, Iran, Japan, Netherlands, New Zealand, Norway, Sweden, Switzerland, United Kingdom, USA) work in four topical areas in this project

• Market — Assessment and Communication

• Design and Analysis

• Demonstration

• Monitoring and Evaluation

The target of this project is to examine in detail residential buildings with exceptional performance in the participating countries. Such successes can be used as models for crafting housing to a very high construction quality, efficient energy production and supply systems and unprecedented thermal comfort by at costs level acceptable in the marketplace. To achieve these goals, the experts are exploring ways to achieve:

• less environmental impact over the life cycle of the building,

• greater reliability for the components, systems and the building as whole,

• increased substitution of renewable for non-renewable energy use,

• lower costs than earlier generations of such housing, and

• more market / occupant oriented design, including special features.

New building components are used, such as high performance windows with overall frame and glass combined U-values less than 0.8 W/m2K, reduced thermal bridges in the building shell, high performance insulation systems and very airtight construction. Energy to supply and temper ventilation air is minimized by using mechanical ventilation systems with high efficiency heat recovery, sometimes coupled with an earth-to air heat exchanger or preheating sunspace. The result is a shortening of the heating season and reduction of the needed heating capacity to such an extent that a conventional heating system is no longer needed. Nor, given the minimal heating energy called for, would a conventional heating system make economic sense. By such small absolute energy quantities to amortize the fixed costs of a conventional system, solar systems become more competitive. They require no chimney sweep, exhaust gas control, meter reader, or service subscription and they have a long lifetime. Finally, given the very small demand on non-renewable energy with the resulting drastic decrease in primary energy demand, detrimental effects on the environment are also reduced. Figure 1 illustrates the path of

energy conversion from primary energy to the end uses of space heating and hot water, taking into consideration the conversion losses outside the building and heat losses inside the building.

In conclusion, new high performance housing shows a way to a new generation of fulfilling domestic needs with drastically reduced primary energy demand and the subsequent impact on the environment. Figure 1 draws, that the primary energy demand can be decrease by extension of renewable energies.