The object of this consultation is the preventive and corrective maintenance of controlled and natural mechanical ventilation installations in all the cities owned or managed by the office, securing the means of access to ventilation installations.

The purpose of this consultation is, on the one hand, the preventive maintenance of controlled mechanical ventilation installations, residential ventilation ducts and high natural ventilation and low ventilation of passageways in common areas due to:

- a visit over the entire duration of the contract on the entire natural ventilation network, common areas and private areas;

- an annual inspection of all the exhaust fans;

- an annual visit to collective conduits;

- an annual visit to housing networks by half of the assets and corrective maintenance on the entire VMC and natural network (replacement of defective parts, etc.). On the other hand, according to the needs of the security services of the means of access to the ventilation installations. The services relate to the property of the OPH which includes: 54 housing estates and a workshop made up of offices 186 extraction boxes 3885 housing units equipped with outlets connected to the VMC network 813 housing units equipped with natural ventilation ducts.