OVK (obligatorisk ventilationskontroll)
OVK is the Swedish scheme for statutory, recurring inspection of ventilation systems in buildings. The purpose is to make sure the indoor climate is satisfactory and that the system works as intended. Norway has no direct equivalent for housing; see the comparison at the end.
The requirement follows from plan- och bygglagen chapter 8, section 25 and plan- och byggförordningen chapter 5, section 1: the owner of the building must arrange an inspection before the system is used for the first time (första besiktning), and then regularly through repeat inspections (återkommande besiktning). One- and two-dwelling houses are exempt from the requirement for repeat inspection. If the home has natural or extract ventilation without heat recovery, it is exempt from OVK entirely; if it has supply and extract ventilation with heat recovery (FT, FX or FTX ventilation), only the first inspection is required.
The interval for repeat inspection follows Boverket's regulation on functional inspection of ventilation systems, section 3, and depends on the building type and the ventilation type: schools, care buildings and similar must be inspected every three years regardless of ventilation type. Apartment blocks, office buildings and similar with natural ventilation (S), extract without recovery (F) or extract with recovery (FX) must be inspected every six years, while equivalent buildings with balanced ventilation with recovery (FT or FTX) must be inspected every three years. Agricultural buildings, industrial buildings and defence buildings of a classified nature are exempt entirely.
The inspection must be carried out by a certified expert funktionskontrollant, with authorisation N (most buildings with simpler ventilation systems) or K (all buildings regardless of ventilation type). Two certification bodies, RISE and Kiwa Certification, certify funktionskontrollanter in Sweden. The owner of the building appoints the inspector; if the inspector neglects their duties, byggnadsnämnden may, under plan- och bygglagen chapter 11, section 34, require that another inspector is appointed.
After each inspection, the inspector must give one copy of the protocol to the owner of the building and send one copy to byggnadsnämnden, and issue an intyg with the date, the result and the date of the next inspection. The owner must then display this intyg in a clearly visible place in the building, not just file it. It is byggnadsnämnden in each municipality that supervises compliance with the rules, in the same way as with other duties under plan- och bygglagen.
Norway has no direct parallel to OVK: there is no statutory, recurring duty to inspect ventilation systems in housing, neither with a certified inspector nor with a displayed certificate. The closest Norwegian relatives are spread across two sets of rules. TEK17 chapter 13 sets requirements for ventilation and indoor climate when buildings are erected or altered, but it is a one-off requirement in the building case, not a recurring inspection of a building in use. For rented and commercial buildings, internal control duties also apply, which require the owner to have systems for detecting and correcting faults in technical installations on an ongoing basis, without setting a fixed inspection interval as the Swedish regulation does.
From Placepoint's dictionary: OVK (obligatorisk ventilationskontroll)
More information: Boverket: Bestämmelser om obligatorisk ventilationskontroll (OVK), plan- och bygglagen (2010:900)
English: Mandatory ventilation inspection (recurring Swedish statutory inspection of building ventilation systems, Swedish-specific).
Frequently asked questions
What is OVK?
OVK is the Swedish scheme for statutory inspection of ventilation systems in buildings, first at installation and then regularly through the life of the building, to ensure a satisfactory indoor climate.
How often must OVK be carried out?
It varies with the building type and the ventilation system. Schools and care buildings every three years regardless of system. Apartment blocks and office buildings with simpler ventilation every six years, and every three years with balanced ventilation and heat recovery. One- and two-dwelling houses have no requirement for repeat inspection.
Who can carry out OVK?
Only a certified expert funktionskontrollant, certified by RISE or Kiwa Certification. The owner of the building appoints the inspector.
Must the result of OVK be displayed?
Yes. The owner must display the besiktningsintyg in a clearly visible place in the building, and the inspector must send a copy of the protocol to byggnadsnämnden.
Is there a Norwegian OVK scheme?
No, Norway has no equivalent statutory, recurring duty to inspect ventilation systems in housing. TEK17 chapter 13 sets requirements when buildings are erected, and internal control duties apply to rented and commercial buildings, but neither matches the Swedish scheme with fixed intervals and a certified inspector.
What happens if OVK has not been carried out?
Byggnadsnämnden supervises compliance and can follow up a missing inspection as a breach of plan- och bygglagen. When you buy a home, a missing or expired OVK certificate is a signal that the ventilation system is not documented as being in order.