Approved document B and F set out the primary requirements for ventilation of enclosed car parks. Compliance will be achieved by either natural ventilation, mechanical smoke extraction or a combination of both methods.

If there is adequate provision for well distributed natural ventilation openings around the car park at each parking level, compliance with Approved Document B and F should be achieved without mechanical extraction.

In circumstances where a car park has provision for natural ventilation, but inadequate as a sole source of ventilation, a supplementary mechanical smoke extract system will be required.

If the car park is enclosed or below ground, and does not have adequate natural openings, a full mechanical smoke extraction system will be required. This will provide smoke clearance and everyday pollution control.

An alternative solution would be for impulse ventilation. As well as controlling the flow of smoke within a car park and keeping large areas effectively smoke free, they can also be used to reduce carbon monoxide levels. This type of system also provides various other safety and cost benefits.