Universelle Energiekennzahlen für Deutschland [Teil 1]

Universal energy ratings for Germany - (Part 1): Differentiated rating distributions according to energy source and energy efficiency standard.

Universal energy ratings for Germany represent an innovative database in which a quarter of a million energy consumption ratings for buildings recorded in past years by the BRUNATA METRONA Group are currently summarised in a standardised form. Data preparation includes (1) a retrospective review of all the meteorological corrections with the aid of new, localised climate factors from the German Weather Service, (2) a subset of 18 rating comparison groups according to three main energy sources and six levels of energy efficiency standard and (3) a continuous illustration of the rating distributions as a function of building size. The medians of the energy rating distributions range between about 80 and 175 kWh·m-2·a-1across all building sizes and comparison groups. Generally, the absolute differences between the medians of the energy rating distributions of new buildings and unrenovated, existing buildings are between 40 and 60 kWh·m-2·a-1. The relative differences for all sizes and energy sources are generally less than 30 %. If one compares renovated and unrenovated buildings directly, the relative figure drops to below 20 % for gas-heated and oil-heated and to about 25 % for buildings with district heating. On the other hand, the statistical distribution ranges of the rating distributions themselves are as wide as ±σ = ±25 to ±55 kWh·m-2·a-1 respectively. The energy rating medians for new buildings built after 1995 and using gas and oil as energy sources are above 100 kWh·m-2·a-1. They are above 80 kWh·m-2·a-1for buildings with district heating. An approach for gauging the possible renovation potential in terms of absolute energy and an extrapolation of the mean value of specific energy consumption for the country's existing rented apartments, weighted in terms of living area and based on the current climate, to approx. 120 kWh·m-2·a-1 are presented.