No, it is impossible to count on universal approaches in already built properties. Firstly, houses are built according to different architectural designs, although there are some buildings of the same type, but not all of them. Secondly, each house definitely has a unique location on the ground, its own personal schemes of electricity supply, water supply, gas supply and so on. It is important to have a good understanding of all the existing methods in order to select the most suitable and less costly options for improving sustainability in each individual case. But it is also important to adapt them to each individual property and integrate them seamlessly into the life of the house.