Certifications such as the Passive House aim to reduce the final space heating energy demand of residential
buildings. The latter are responsible for a significant share of final energy consumption in Europe of
which nearly 70% is associated with space conditioning, notably heating. The improvement of the energy
efficiency of residential buildings, in terms of space heating, can therefore reduce their total energy
demand.
However, most certifications totally overlook other energy requirements associated with residential
buildings. Studies on passive houses do not take into consideration the embodied energy required to
manufacture the building materials, especially the large amount of insulation required to achieve high
operational efficiencies. At an urban scale, most passive houses are single family detached houses located
in low density suburbs with a high car usage, resulting in considerable transport related energy demand.
This paper analyses the total life cycle energy demand of a typical Belgian passive house, comprising
embodied, operational and transport energy. It relies on a comprehensive technique developed by Stephan
et al. [1] and conducts a parametric analysis as well as a comparison to alternative building types.
Results show that current building energy efficiency certifications might not ensure a lower energy
demand and can, paradoxically result in an increased energy consumption because of their limited scope.
More comprehensive system boundaries should be used to make sure that net energy savings do occur.
The embodied energy of passive houses can represent up to 77% of the total embodied and operational
energy over 100 years. Also passive houses can have nearly the same energy consumption as a standard
new house with the same geometry, location and number of occupants. A retrofitted apartment in the
city has an energy consumption 15.2% lower than the best passive house scenario