Since 1991 has Sweden regulations on compulsory inspection of ventilation systems (OVK). Thereasons to issue these regulations were many studies on poor indoor climate and health problems for building occupants. The studies have shown also that poor upkeep and maintenance have led to a decline in the performance of existing ventilation systems. If, in the future, we do not look after ourventilation systems properly and adapt operation and maintenance to current user habits, then evenmore buildings will become problem buildings. More people will suffer health problems unnecessarily.2003 had Boverket a poster presentation on these regulations at the 24th AIVC Conference inWashington, USA. 2007 - 2009 have been OVK-regulations changed because of EPDB (EnergyPerformance of Buildings Directive) and new Swedish National Regulations on Energy Declaration of Buildings.2008 had Boverket issued "Regulations for Performance Checks on Ventilation System, OVK" withrules and recommendations to them.A new edition is coming in April 2009 concerning the last revision on inspection intervals and differentinspector qualification classes. Regulations are able to load free from Boverket web-sitewww.boverket.se. Just now only in Swedish but an English edition shall come next year.