Building regulations require the provision of ventilation to all basements (heated or unheated) to adequately control moisture vapour, be it generated internally or brought through from the structure. Cross ventilation or passive stack ventilation are the most effective forms of natural ventilation although continuous mechanical ventilation may be required depending upon proposed use and internal arrangement of rooms.
For spaces with anticipated high levels of humidity, such as utility rooms, bathrooms or gyms, mechanical ventilation is essential.
Ventilation should be directly applied to exposed external walls where possible i.e. not through the basement retaining walls. Stack ventilation (i.e. ventilation through a vertical vent duct) or mechanical ventilation which can be the preferred method of providing natural crossventilation, provided it does not compromise the fire compartmentation strategy of the development. This can be effectively provided by the staircase linking basement and ground levels, provided no fire separating doors are required.
Please refer to Part F (ventilation) of our building regulations guide for further information. All information correct as of 2013 amendments.