 Replacement
Windows
Windows normally provide natural ventilation and daylight to
a room and may act as a means of emergency escape in the event
of fire.
Building Standards Approval is necessary for works which may
involve alterations to a wall to incorporate a window - such as
removal of load bearing mullions or enlarging a wall opening.
Building Standards Approval
There is no need to obtain Building Control Approval to carry
out window replacement.
However, if the replacement is by a window which is not of the
same type as the one being replaced it must comply with the relevant
sections of the Building Regulations. If the replacement window
is of the same type as the one being replaced special care must
be taken with such replacements to ensure that the new window
design will not fail to meet the regulations to a greater degree.
Building Regulations
The minimum statutory requirements for replacement windows include
the following:-
- Ventilation
The total opening area of a window or windows of a naturally
ventilated room must be not less than 1/30th the floor area
of the room. A trickle ventilator may be incorporated within
the window frame. The size of the trickle ventilator may vary
between a minimum, per room, of 4,000mm2 to 8,000mm2 - depending
on the type of room, providing that the overall average for
the dwelling is not less than 6,000mm2 per room. Some part of
the window opening, including a trickle ventilator, must be
not less than 1.75 metres above floor level.
- Daylighting
The area of glass of a window or windows must be not less than
1/15th of the floor area of an apartment.
If the apartment has an external glazed door then this glazing
may be included.
- Safety Aspects
- Where any part of a window in a dwelling is above 4 metres
from ground level both external and internal surfaces of
the window should be able to be cleaned safely from the
inside e.g. without the use of a step ladder.
- No opening part of a window should project so as to cause
a danger to the public.
- If any part of a window is less than 800mm from floor
level the opening should be protected by a barrier (this
may include an appropriate type of glass), suitably constructed
to prevent anyone falling through the opening.
The type of glass may vary depending on its height from
floor level and consultation should take place with the
installer.
These illustrations are from BS 8213 : Part 1:1991 and
are reproduced with the permission of BSI under licence
no. PD\1998 0954.
- Emergency Escape Windows
Emergency escape windows are intended to allow the occupants
of a dwelling the option of unaided escape from the dwelling
in the event of other escape routes being unusable.
An emergency escape window should be provided in every apartment
in an upper storey of a dwelling at a height of no more than
4.5 metres from ground level, unless there is more than one
way out of the apartment excluding the window.
An emergency escape window should also be provided in any
apartment which is an inner room, unless there is an alternative
route out of the room.
Satisfactory dimensions of an emergency escape window would
be a clear opening of 850mm. in height and 500mm. in width,
providing unobstructed exit. However, it is recognised that
alternative dimensions may still be acceptable, and advice
should be taken from the Building Control office.
Definitions
- Apartment:
Means a room not used solely as a kitchen, store, utility
room, bathroom or toilet.
- Dwelling:
Means a unit of residential accommodation occupied (whether
or not as a sole or main residence)
(a) By a single person or by people living together as a
family; or
(b) By not more than six residents living together as a
single household (including a household where care is provided
for residents).
- Inner Room:
Means a room, other than a kitchen, bathroom or toilet which
does not have a direct access to an exit nor direct access
to an enclosed circulation area (e.g. hall) having an exit.
Notes
(a) Exemption from Building Control Approval is not exemption
from other forms of permission such as Planning Consent, Listed
Building Consent, etc.
(b) The installer of replacement windows should be advised of
the need to comply with the relevant Building Regulations prior
to commencement of installation.
(c) This guidance gives a broad view of the requirements for
replacement windows in dwellings and if more detailed information
is required it is necessary to refer to the Technical
Standards to comply with the Building Standards (Scotland)
Regulations.
For further information please contact
the Building Standards office.
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