In an embodiment, the present invention provides a gas insulated switchgear for medium- or high-voltage use, including: a closed housing of a switchgear compartment having insulating gases or fluids. The insulation gas includes sulfurhexaflouride (SF6). Constructive features of the switchgear are designed such that they are overperformed for the use of sulfurhexaflouride (SF6), but already sufficiently performed for the use of eco efficient insulation gas with a mixture of up to 20% fluoroketone C5F10O and air or oxygen and carbondioxide. A later retrofit or adaption to a switchgear, filled with eco-efficient insulation gas, only needs the aforesaid gas exchange, without exchanging constructive parts of the switchgear.