A sustainable and environmentally responsible building concept aims at a high workplace comfort,
a significantly reduced heating and cooling demand, a high-efficient plant system, and the use of
renewable energy sources to condition the built environment. This paper presents a comprehensive
analysis of the heating and cooling concepts of 11 low-energy buildings in terms of energy use, efficiency
and occupant thermal comfort. All buildings investigated employ environmental energy sources and
sinks – such as the ground, ground water, rainwater and the ambient air – in combination with thermoactive building systems. A limited primary energy use of about 100 kWhprim/(m2neta) as a target for the
complete building service technology (HVAC and lighting) was postulated for all buildings presented.
With respect to this premise, a comprehensive long-term monitoring in high time resolution was carried
out for two to five years, with an accompanying commissioning of the building performance.
Measurements include the useful heating and cooling energy use, auxiliary energy use for the hydraulic
system, as well as end and primary energy use, occupant thermal comfort and local meteorological
conditions. A new methodology is proposed for a holistic approach to the evaluation of heating and
cooling concepts, which not only considers the occupants thermal comfort, but also the useful energy
consumption and the efficiency of the generation, distribution and delivery of heating and cooling
energy.