Towards very low energy buildings

Very low energy buildings are designed to provide a significantly higher standard of energy efficiency than the minimum required by national Building Regulations. They are very often designed without traditional heating systems and without active cooling. They result in a saving of energy consumption of 70 to 90% compared to the existing building stock.

Examples of such buildings are: Passiv Haus (Germany), BBC - Bâtiment Basse Consommation - Effinergie (France), “zero” carbon house (UK), Minergie (CH) …

The definition of very low energy buildings varies significantly across Europe. The variation exists in terms of the absolute possible level of energy consumption; the calculation methods and the energy flows included in the requirements vary from country to country…

Most of the official calculation methods deal with the calculation of the primary energy consumption of buildings. However, what processes and how the corresponding energy demand is converted into primary energy differ from country to country. In some cases the primary energy consumption is converted into CO2 emission. The definition and consequently the calculation of primary energy consumption is strongly dependant on the chosen boundary for calculation.

Therefore, direct comparison between the different “standards” is not possible.

Comparison of the energy calculation methods of Minergie and Effiinergie, with the two energy frames as defined in the Passive House standard (total energy consumption and heating consumption per year).

Nevertheless, one thing is common to all of them: they follow the principles of the Trias Energetica. They all require high performing building envelops and reduced energy needs for heating and cooling.
With its unique experience in energy efficiency in the building sector, Saint-Gobain ISOVER is definitely engaged in the promotion of very low energy buildings (new construction and renovation projects). We consider that cost effective technologies already exist that allow achieving (at the building level) very ambitious objectives in terms of reduced energy consumption and low CO2 emissions (under the condition that the previously described principles of the Trias Energetica have been followed).

ISOVER is engaged

We consider that very low energy building standards should become the common rules in all countries before 2020: we push for national building regulations to be improved in this direction.

We also strongly commit ourselves to demonstrate that very low energy constructions and renovations are already technically and economically feasible:

  • We have developed the Multi-comfort House concept that we are promoting in all the countries where we are active; the Multi-Comfort House is a very low energy house with enhanced comfort for the occupants ; it can be built under any climate as we have adapted the concept to different climate conditions (moderate, hot and cold climates); we carry out pilot projects in different country: by building locally Multi-comfort Houses, we demonstrate to all the stakeholders in the building chain that dreams can become reality…

  • We constantly further improve the thermal performances of our insulation solutions and products to make the design and the construction of very low energy buildings always easier and more cost-effective;
  • Moving towards very low energy constructions is a very challenging market transformation for all the partners in the building sector: we invest in promotional and training activities to support those who are starting the “learning curve” to progress quickly down the curve;
  • We support national initiatives to develop voluntary certification and labelling schemes for very low energy constructions (PassivHaus in Germany and in Austria, Minergie in Switzerland, Effinergie in France…); we encourage Governments to adopt financial schemes (loans with low interest rates, governmental subsidies, lower taxes…) to make these kinds of buildings more attractive and to turn the voluntary certification schemes into mandatory ones.

Benefits of low energy buildings

Lower energy bills : owners or occupants of low energy building can keep their energy costs under control and become less vulnerable to future fluctuations of energy prices;
Excellent indoor climate : in a building without draughts, the use of mechanical ventilation flows the air pollutants away and provides fresh air indoor;
Pleasant warmth : both in winter and in summer, large fluctuations in temperature are not practically non existent.
Better acoustical and visual comfort : bioclimatic design and performing insulation of the glazed and opaque wal
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