OVK - Obligatory Ventilation Control

Reviewed: 10 February 2021

An Obligatory Ventilation Control, OVK, must be carried out regularly, in all buildings. Its purpose is to show that the indoor climate is good and that the ventilation systems are functioning. The control must be carried out by a certified inspector. The controller must also provide suggestions on how to reduce energy consumption for ventilation without this giving rise to a poorer indoor environment.

It is the owner of the building, such as a tenant-owner housing association, that must ensure that an OVK is carried out. The owner must select an expert performance controller who is certified by an accredited certification body.

The OVK requirement has existed since 1991. The municipal Building Committee should have an OVK report for the building from regular controls.

Here you can read about the regulations in brief. You may also choose to read Boverket's full code for OVK (in Swedish only). You can also read about the servicing and maintenance of ventilation systems in our checklist for ventilation.

An OVK must be performed regularly

An OVK must be carried out before a ventilation system is put into service for the first time (initial inspection). For most buildings, an OVK must then be carried out on a regular basis, every 3 or 6 years (periodic inspection). See our table of intervals for different categories of buildings under elaboration up in the right corner.

Every OVK must control that

  • the ventilation system does not contain pollutants that might be spread in the building
  • instructions and maintenance directions are easily available
  • the ventilation system is otherwise functioning in the intended manner.

The initial inspection must, in addition, control that

  • the function and properties of the ventilation system are compatible with current mandatory provisions.

At periodic inspections, the performance controller must

  • control that the function and properties of the ventilation system are on the whole compatible with the mandatory provisions that were in force when the system was put into use
  • examine the measures that can be taken to improve energy management in the ventilation system and that do not result in a deterioration in the indoor climate.

It is the building's owner who then has to decide whether the proposed energy efficiency measures will be implemented.

Send the report to the municipality

For each inspection, the performance controller must write a report containing the results. The controller must point out faults and deficiencies in the ventilation and note these in the report. The controller must sign the report and give a copy to the building's owner and send a copy to the Building Committee.

Put up the certificate in the building

The performance controller must issue a certificate showing that the inspection has been carried out, with the date of inspection, the results of the control and the date for the next inspection. The building's owner must put up the certificate in a clearly visible place in the building.

Rectify faults and deficiencies immediately

The building's owner must ensure that faults and deficiencies discovered at an OVK are immediately rectified. The owner is responsible, even between inspections, for taking the measures needed to meet the requirements on the ventilation system and for ensuring that it is serviced so that its essential technical properties are maintained. The requirements are found in the building legislation.

The municipality is responsible for control and supervision

It is the responsibility of the municipal Building Committee to ensure that building owners discharge their OVK responsibilities. If a building's owner does not implement an OVK, the Building Committee may order the owner to implement one. If a report shows that the requirements for performance control are not being met, the Building Committee may order the owner to rectify the deficiencies.

Further information

Boverket may not provide additional information to what is stated on the website.

For more information on this issue, we recommend that you contact the relevant municipality.

 

Reviewed: 10 February 2021

OVK – Which buildings and when?

Below is a table showing the inspection intervals and authorisation levels required for different categories of buildings.

FT-ventilation = mechanical ventilation in which both the extract and supply air flows are controlled by fan.

F-ventilation = mechanical ventilation where the extract air flow is controlled by fan.

S-ventilation = natural ventilation.

FTX-ventilation and FX-ventilation = FT-ventilation and F-ventilation with heat recovery.

N = normal authorisation level.

K = complicated authorisation level.

Buildings Inspection interval (periodic inspection) Performance controller's lowest authorisation level
Pre-schools, schools, health care premises and the like with S, F, FX-ventilation 3 years N
Pre-schools, schools, health care premises and the like with FT, FTX-ventilation  3 years K
Multi-dwelling blocks, office buildings and the like with FT, FTX-ventilation 3 years K
Multi-dwelling blocks, office buildings and the like with F, FX, S-ventilation 6 years N
Single and two-dwelling houses with FX, FT, FTX-ventilation Control only for new construction and new installation N
Boverket (2021). Obligatory Ventilation Control. https://www.boverket.se/en/start/building-in-sweden/swedish-market/laws-and-regulations/national-regulations/obligatory-ventilation-control/ Fetched 2024-12-05