Universelle Energiekennzahlen für Deutschland [Teil 2]

Universal Energy ratings for Germany — (Part 2): Evolution of rating distributions according to year of building construction

To date, "Universal Energy Ratings" for Germany contain about a quarter of a million energy consumption ratings recorded by the BRUNATA METRONA Group within the recent six year period. Data processing comprises a retro perspective review and normalisation of all energy ratings according to new, localised climate factors from the German weather service. A subset of 110.000 energy ratings concerning gas- and oil-heated buildings only — half of those built past 1977 — has been analysed statistically by creating energy rating distributions depending on construction year, focussing exclusively on unrenovated objects (according to 1995 standards) built prior to 1995 and new buildings constructed in 1995 or later. It is shown, that the median values of rating distributions from about 1900 up into the 1960ies appear relatively constant around 155 kWh/(mm²a). For building construction years within this time interval 90 % of today's energy ratings (5 % to 95 %-percentiles) fall into the range between 100 and 260 kWh/(mm²a). For construction years after the mid 1960ies the median values continuously decrease to about 85 kWh/(mm²a) today. Their corresponding standard deviations decreased by a factor of two from above 50 kWh/(mm²a) to about 25 kWh/(mm²a). The most distinct relative decrease occurred between 1994 and 1995 when the WSVO'95 was activated. This work adds a direct comparison between the recorded today energy ratings and the typical requirement levels of the various heat insulation regulations, WSVO, and Building Energy Conservation Ordinances, EnEV, concerning building construction years starting from 1977. We also present parameterization functions for the most important rating distributions that could be utilized for general model calculations and extapoletions to picture future energy efficiency evolution.