Buildings and the Passive house

Three critical issues that our world faces today are energy conservation, global warming and the need for more quality housing. The solutions to these issues, however, do not always seem to fall neatly in line: How can we decrease carbon dioxide emissions and reduce energy use in existing homes, whilst simultaneously dealing with increased energy demand and emissions due to the growing overall number of homes?

Insulating a normal building with polyurethane will go a long way in reducing its carbon emissions but increasingly better technology and increased use of polyurethanes is leading new architectural and environmental heights. A concept born in Northern Europe for energy-saving construction – the passive house – was designed as a solution to the problems of increase energy demand and energy efficiency. Passive houses are a type of “low-energy” building, also dubbed “eco” or “green” building. They are buildings designed to provide a comfortable indoor climate in winter without the need for a conventional heating system. In order for housing to create this environment and therefore live up to passive house standards, they must therefore boast dramatic reductions in energy consumption and zero carbon emissions.

Passive houses typically use high levels of insulation such as polyurethane panels, energy efficient windows, low levels of air infiltration and heat recovery ventilation to lower heating and cooling energy. Through these technologies, passive houses use roughly 85% less overall energy. In the United States, a house built to the passive house standard uses between 75 and 95% less energy for space heating and cooling than current new buildings that meet today's US energy efficiency codes. At present more than 12,000 such houses have been built in Europe, mostly located in Germany, Austria and Scandinavia.

It is true that the initial cost of building energy efficient housing is generally higher due to the extra costs associated with improved insulation. Most entrepreneurs are also not used to the new technologies and much time and resources are invested in planning, education and quality assurance – raising costs. However, for passive buildings, these are simply short-term costs, which will soon be returned. If a house is built as a passive house, one can actually save money for not having to install a radiator system at all. At this level of energy efficiency, the gains from energy savings will also be significant.