Energy properties in urban building stock

The study analyses the energy economic properties of a sample of 3800 buildings located in urban areas around Finland.On the basis of data collected of the buildings and their energy consumption, the significance of the various factors bearing on their energy-economic properties was examined.The energy conservation potential in various kinds of buildings was also examined. Oil accounts for 3/4 of the fuel used in heating the buildings under study, including oil used in district heating systems.Over 30 % of the overall building volume actually being heated is served by district or regional heating.The specific consumption of heating energy in the buildings studied fluctuates widely between types of buildings, with annual values of between 30 and 140 kWh/m³ (4-20 litres of oil/m³).Aside from the variations in function, size, etc., between buildings, the consumption of heating energy is greatly influenced by the maintenance and use patterns prevailing in any given building.Interior temperature levels and the use of ventilation clearly account for much of the dispersion in consumption values.A twofold increase in the volume of the building brings about a lowering of specific consumption by 5-10 %.Older buildings consume less energy per unit volume than do those erected in the 1960's and early 1970's, in which the heat consumption is greatest.Buildings constructed since 1975 consume over 10 % less energy than the average.It is possible within cost effective limits to reduce energy consumption in the Finnish urban building stock by one third during the 1980's.Of the savings to be obtained, a quarter (4 TWh) can be achieved by changes in user habits, and the remainder (13 TWh) by various repair and renovation measures.