In the Secretary of State’s view the requirement of Fl will be met if ventilation is provided which under normal conditions is capable (if used) of restricting the accumulation of such moisture (which could lead to mould growth) and pollutants originating within a building as would otherwise become a hazard to the health of the people in the building.

This could be achieved by the provision of ventilation to:

a. - extract, before it is generally widespread, water vapour from areas where it is produced in significant quantities (eg kitchens, utility rooms and bathrooms);

b. - extract, before they are generally widespread, pollutants which are a hazard to health, from areas where they are produced in significant quantities (eg rooms containing processes which generate harmful contaminants and rest rooms where smoking is permitted);

c. - rapidly dilute when necessary, pollutants and water vapour produced in habitable rooms, occupiable rooms and sanitary accommodation;

d. - make available over long periods a minimum supply of fresh air for occupants and to disperse where necessary, residual water vapour. Such ventilation should not significantly affect comfort and where necessary, should be reasonably secure and provide protection against rain penetration.


e. - mechanical ventilation or air-conditioning systems proposed for non-domestic buildings would satisfy the requirement if they provided, as necessary, the ventilation as set out in (a) to (d) above and are:

f. - designed, installed and commissioned to perform in a way which is not detrimental to the health of the people in the building; and

g. - designed to facilitate necessary maintenance for the purpose of (e) and (f) above.

x Definitions

0.1 - A ventilation opening can include any means of ventilation (whether it is permanent or closable) which opens directly to external air, such as the openable parts of a window, a louvre, airbrick, progressively openable ventilator, or window trickle ventilator. It also includes any door which opens directly to external air.

0.2 - Habitable room means a room used for dwelling purposes but which is not solely a kitchen.

0.3 - Bathroom means a room containing a bath or a shower, and can include sanitary accommodation.

0.4 - Sanitary accommodation means a space containing one or more closets or urinals. Sanitary accommodation containing one or more cubicles counts as a single space if there is free circulation of air throughout the space.

0.5 - Utility room means a room designed to or likely to be used to contain clothes washing and similar equipment such as a sink, washing machine, tumble dryer or other feature or equipment which may reasonably be expected to produce water vapour in significant quantities.

0.6 - Occupiable room means a room in a non-domestic building occupied by people such as an office, workroom, classroom, hotel bedroom, etc. but not a bathroom, sanitary accommodation, utility room or rooms or spaces used solely or principally for circulation, building services plant and storage purposes.

0.7 - Domestic buildings mean those buildings used for dwelling purposes including dwelling houses, flats, student accommodation and residential homes.

0.8 - Non-domestic buildings mean all other buildings, including buildings where people temporarily reside, such as hotels.

0.9 - Passive stack ventilation (PSV) is a ventilation system using ducts from the ceiling of rooms to terminals on the roof, which operate by a combination of the natural stack effect, ie the movement of air due to the difference in temperature between inside and outside, and the effect of wind passing over the roof of the dwelling.

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