With their building envelope, which is delimited by the floor slab, basement and exterior walls, doors and windows as well as the roof, residential buildings offer many possibilities for energy saving.

A building loses around 20% of the energy through the roof, heating requires around 30%, through the windows around 20%, the outer walls around 20%, the floor around 5% and through the ventilation (leaks) around 5% of energy.

First of all, you should know, what you want to achieve.

A single measure, e.g. simply replacing windows or a new roof. If available, the applicable requirements must be observed.

Or maybe the renovation to an efficiency house? Then the overall result counts.

All renovations have one thing in common. One has to investigate which measure is most economical.

If an area of 50% or more of the building envelope is changed, a hydraulic balance must be carried out. The reason for this is that the building's energy requirements change and the heating has to be adapted.

It is important to have a holistic concept in order to rule out subsequent structural damage and mold formation. In addition, a one-step renovation results in cost savings, since, for example, scaffolding and construction site equipment are only required once.