The most cost-effective energy reduction in a building usually occurs during the design process if an efficient construction philosophy is applied. Today we have the technology to build considerably more energy efficient buildings. They consume much less energy than the required minimum dictated by current building codes and energy standards. This is also possible with refurbishing.

Energy discussions tend to focus a lot on energy sources. But our energy sources are not infinite and we cannot reach the EU climate goals without also focusing on energy efficiency. When planning the energy system of a building, the Kyoto pyramide offers guidance. (Dokka, T.K. and Rdsj, A. 2005)

 

 

Low-energy buildings typically use high levels of insulation, energy efficient windows, low levels of air infiltration and heat recovery ventilation. They may also use passive solar building technique or active solar technologies. Other aspects that are important to consider are building orientation, adoption to local climate and topography, window placement, overhang depth and the efficiency of heating, cooling, lighting and other equipment.

A passive house is a building where heat loss has been reduced to such an extent that no radiators or under-floor heating are necessary. On the coldest days, slight pre-heating of the incoming ventilation air is sufficient to keep the house warm. This is achieved through the use of a small heating element the size of a hair dryer, with either warm water or electricity as the heating medium. The reduced heat loss is achieved by sealing the house so well that it is ventilated by a ventilation system and not as a result of leaks. This means that the warmth contained in the heated air can be recovered. The house is also better insulated and has fewer thermal bridges.

 

Sorce: Passivhuscentrum, Alingsås, Sweden

 

To be a passive house a building must fulfil different conditions. The passive house standard was defined in 1988 and the first passive house was built in Darmstadt, Germany in 1990.

Zero Energy Buildings, Zero Carbon Buildings and Plus Energy Buildings are definitions that indicate that that energy conservation technology is mixed with the active use of renewable energy sources. Compared to the passive house standard there is no exact definition of these types of buildings.