Why does saving energy pay?
Between the vision of zero-energy houses and the reality of the inefficient energy-using houses we often live in today, there are enormous possibilities for intermediary solutions.
Among them, there are solutions which are currently economically optimal. According to available assessments the most profitable solutions go beyond the legal requirements of the thermal building protection –meaning that applying more energy saving measures than are legally required pays. This means that current legislation is not fully coherent with the energy prices. Nothing stimulates saving energy better than energy prices do. The higher energy prices are, the stronger the stimulus for energy saving and efficient energy use. With the fast growing energy prices, it seems unreasonable to build houses with an annual heat demand higher than 50 kWh/m2.
A properly performed thermal insulation of a building allows gaining energy self-dependency and climate neutrality of the building at a much lower cost. For instance, it is quite easy to pass from a passive house to a zero-energy building. All the energy required for the house could be generated by installing on the roof approx. 20 m2 of solar PV cells.
However, if one wanted to make a poorly insulated building an energy self-dependent one, one would have to install 10 times more solar PV cells! This would not be profitable at all.
The only economically justified practice in construction is to insulate and save energy wherever it is possible.
Polish