The building codes of the German states oblige the owner / developer to properly maintain the construction
products and components used, as "buildings and structures (...) shall be arranged, erected, modified and maintained so that they do not put public safety and order at risk, in particular the life, health and natura livelihoods“.
According to the building codes of the ststes, building products may not be used without proper maintenance.
According to DIN 31051: 2003-6 "Maintenance principles", (preventive) maintenance is the generic term for
servicing, care, inspection, repair and improvement.