ZENNOR CONSULTANTS

Rapid ventilation by one or more openings with a total area of at least 1/20th of the floor area of the room, with at least some part of the opening at least 1.75m above the floor level; or mechanical extract ventilation capable of extracting air at a rate not less than 6 l/sec, which may be operated intermittently with 15 minutes overrun... Each room must be provided with appropriate rapid and trickle ventilation (each window does not necessarily require trickle ventilators to be fitted)... Mechanical ventilation rated as capable of extracting at a rate of not less than 60 l/sec (or incorporated within a cooker hood and capable of extracting at a rate of 30 l/sec) or PSV. Rapid ventilation by opening window.