If you own, manage or live in a building in Sweden you will sooner or later meet the term. A notice on the stairwell door announces that an "OVK" is about to take place, and the questions start. Let us answer them in plain English.
What is OVK?
OVK stands for obligatorisk ventilationskontroll, Swedish for mandatory ventilation inspection. It is a legally required check of the ventilation system in most buildings in Sweden. The purpose is simple: to make sure the indoor air is healthy and that the ventilation works as it was designed to.
OVK at a glance
- What it is: a mandatory, periodic inspection of a building's ventilation system.
- Required since: 1 January 1991.
- Legal basis: the Planning and Building Act (PBL, chapter 8, section 25), the Planning and Building Ordinance (chapter 5) and the regulations of Boverket, the Swedish National Board of Housing, Building and Planning (BFS 2011:16 OVK).
- Who is responsible: the property owner. In a housing cooperative (bostadsrättsförening, BRF) that means the board.
- Who carries it out: an independent, certified ventilation inspector (funktionskontrollant).
- How often: every 3 or 6 years, depending on the type of building and ventilation system.
- Result: an inspection protocol that is sent to the municipality, and a certificate that is displayed in the building.
Why does OVK exist?
In the late 1980s it became clear that many Swedish buildings had poor ventilation. The result was stale air, moisture damage and health complaints such as fatigue, headaches and allergies. To tackle the problem, the government introduced mandatory ventilation control on 1 January 1991.
The aim is to protect people's health, to make sure ventilation systems work as intended and to promote energy-efficient operation. Most of us spend more than 90 percent of our time indoors, so the quality of the air in homes, workplaces and schools matters more than many people think.
What is checked during an OVK inspection?
The inspector looks at how the whole ventilation system performs, not just at a single fan or vent. In practice this means:
- reviewing drawings, system data and earlier protocols;
- measuring air flows at vents in kitchens, bathrooms and other rooms;
- testing fans and controls and inspecting filters, ducts and air terminal devices;
- comparing the results with the requirements that applied when the building was constructed;
- assessing hygiene and function, for example that air is not spreading between apartments.
It is a measurement of how the air actually moves through the building, not a quick visual check.
Who is responsible for OVK?
The property owner is always responsible for making sure OVK is carried out within the required interval. In a housing cooperative the board is responsible on behalf of the association. Tenants and apartment owners do not carry the legal responsibility, but they are expected to give the inspector access to their home when the inspection takes place.
The owner books a certified inspector, informs the residents in good time, and makes sure the inspector can reach all relevant parts of the building. Owners remain responsible for fixing any deficiencies that the inspector finds.
How often must OVK be carried out?
The interval depends on the type of building and the ventilation system:
| Building and ventilation system | Interval |
|---|---|
| Preschools, schools, healthcare premises and similar buildings, regardless of system | Every 3 years |
| Apartment buildings, office buildings and similar, with FT or FTX ventilation | Every 3 years |
| Apartment buildings, office buildings and similar, with S, F or FX ventilation | Every 6 years |
| Detached and semi-detached houses with FX, FT or FTX ventilation | One initial inspection before the system is taken into use, then no recurring inspections |
The abbreviations describe the ventilation system:
- S is natural (self-draught) ventilation.
- F is mechanical exhaust ventilation, where only the exhaust air flow is fan-controlled.
- FT is mechanical supply and exhaust ventilation, where both flows are fan-controlled.
- FX is exhaust ventilation with heat recovery.
- FTX is supply and exhaust ventilation with heat recovery.
A new OVK is also required if the ventilation system is rebuilt or changed in a way that affects its function, even if the regular inspection is not yet due. Not sure what applies to your property? Contact us and we will help you find out.
Which buildings are exempt?
Detached and semi-detached houses with natural (S) ventilation do not need recurring OVK. Agricultural outbuildings and industrial buildings that are not used by people are also exempt, and so are certain protected structures. Houses with mechanical ventilation need only the first inspection when the system is taken into use. Exemptions from OVK are very unusual and are decided by the municipality.
What happens if OVK is not carried out?
OVK is a legal requirement. If it is not done, the municipality can order the owner to carry it out and can impose a financial penalty (vite) if the owner does not comply. A missed inspection can also affect the value of the property and the terms of its insurance. The biggest risk, however, is that ventilation problems go unnoticed. Poor air quality is not always obvious, but it affects both the people in the building and the building itself.
If the inspection finds deficiencies, the owner must fix them within the stated time and then have a follow-up inspection.
What does OVK mean if you live in an apartment?
For residents, OVK mostly means that an inspector needs to enter your home on the day of the inspection, and that you should keep the ventilation vents free of obstacles beforehand. You cannot refuse access: if access is denied, a repeat visit may be required and the cost to the association increases.
Even if the air feels fine in your apartment, that does not mean everything works in the whole building. Ventilation is connected between apartments, so an imbalance in one place can affect another. That is why OVK covers the entire property.
What does OVK cost?
Every property is different, so there is no standard price list. The cost depends on the size of the building, the type of ventilation system and the number of apartments or premises to inspect. Request a quote and you will receive a fixed price adapted to your building, normally within 24 hours. More questions? See the frequently asked questions.
Summary: what is OVK?
OVK is a legally required inspection of the ventilation in a building. It makes sure the air is healthy and that the systems work as they should. For property owners and boards it is about responsibility. For residents it is about something very simple: that the air at home is as good as it should be.