Energy efficiency in apartment buildings
Most buildings in Estonia are energy inefficient. The average annual heating energy used in the buildings is 200-400 kWh/m² compared to the figure in industrial nations with a similar climate which is only 150-230 kWh/m². Thus Estonians consume more energy and also pay quite a lot for it.
Rapidly rising energy prices not only lead residents to supplement the heating insulation of the buildings, but also they are forced to. Above all, additional insulation is a way of saving both on a personal and on a national scale. The microclimate of the rooms can be improved by the insulation. In addition, the less energy is used the less the environment is damaged.
The heat conductivity of the buildings´ floors and walls is described by the U-value expressed in W/mK. In order to calculate the heat saved by improving the outer shell of the building, the original U-values of the shell structures must be found before changes are made. One must also evaluate what the attained values will be after the changes have been made. The amount of heat energy transferred through construction materials depends on the heat conductivity of the various materials used and the thickness of the walls/floors.
A building’s heat losses stem mainly from the exterior walls, windows, the roof, outer doors and from the basement floor.