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