Public maintenance funds, also known as housing for the aged or overhaul fund, generally charge 2%-3% of the house price. It is mainly used for large and medium-sized repairs of public parts and public facilities after the warranty period expires, as well as the renovation of public facilities and equipment in residential areas. The public part refers to the main load-bearing structure of the house (including foundation, internal and external load-bearing walls, columns, beams, floors, roofs, etc.). ), outdoor walls, hallways, stairwells, corridors.