Windows repair inside.ai - Wyre Forest District Council

Repair or replace?
What materials should I use?
Whether to repair or replace a window will nearly
always come down to the cost, although this is not
always the case. Many people change windows as
a first resort in making their home more sustainable,
and more heat efficient. Whilst this is very
commendable, little thought goes into either the cost
effectiveness of such replacements or the savings
they will make in changing their windows. With a top
estimate of 15% of the total heat from a house lost
through the windows, this is rarely a sensible first
option for thermal efficiency.
Traditionally, windows have been made from materials
which have been readily available, but also which have
the strength to support the glazing. Until the C18th, oak
or other similar hardwoods were used for the window,
providing a readily availablesource of strong timber.
This was gradually replaced during the C18th, with the
introduction of slow growing softwoods, often wrongly
referred to as pitch pine.
When complete
replacement is
deemed
necessary
thought should
be given on the
impact on the
building itself,
and on the
street-scene, especially within sensitive areas of
control, such as Conservation Areas, as this can have
a dramatic impact on the appearance of the area.
With regards to historic buildings, it is generally better
to retain as much of the original window as possible,
and repair the rotten or broken
elements, as this will retain a higher
grade of wood than will generally be
available today, and will also retain
the historic section and style, which
can often be hard to replicate.
However, if the window is beyond
sensible repair, then the best course
of action would be to replace the
window, in the same style, materials
and size, even though this may require a bespoke
window to be constructed, rather than get an properly,
“off-the-shelf” window which may not fit or be in the
same style.
The Mark of Responsible Forestry
In replacing or repairing any
windows, the correct timber
needs to be used – a standard
timber from a DIY store, such
as Nordic pine, will not suffice
– it is likely that this will be a
fast grown commercial timber,
© 1996 FSC A.C
with poor structural qualities,
and will have little defence against rot or decay.
It is also always advised that any timber used for
construction be FSC certified, and is bought from a
reputable source.
It is never recommended that Upvc or plastic windows
be inserted into listed buildings. However, manypeople
purchase Upvc windows on the basis that theyare
maintenance-free, will last longer than timber windows,
and are being environmentally by insulatingtheir
house, none of which is completely correct. Whilst they
may not need the same degree of care a timber
window will require over its life,
they still need looking after,
seals checking, and of course
cleaning. It can also readily
be seen that Upvc windows
do not last longer than good
quality timber windows – with
evidence in every street
showing that timber windows
can last over 300 years, whereas
many Upvc windows will
require replacing in an average of 20 years. In terms
of environmental soundness, as long as the timber
for any window is FSC certified, this will ensure that
the timber used is taken from a sustainable source,
and will not be damaging to the environment –
opposing this, the creation of Upvc is a by-product
of the oil and petrol industry, and through both its
manufacture and degradation, releases more toxins
into the atmosphere than many other industrial
processes. Whilst the Upvc industry has improved
in this aspect, and has made concerted efforts at
recycling, it still cannot compare with FSC certified.
Double glazed or single glazed?
As a general rule, and one
which is held nationally,
through most Local Planing
Authorities, and English
Heritage, the use of doubleglazed units in Listed Buildings
is not supported in this
District. Where such units
have been installed, it is
likely that this will result in
enforcement action for their
replacement. Furthermore,
recent research by English Heritage has found
that properly working single glazed windows, with
appropriate draft excluders, can achieve nearly the
same thermal efficiency as a double-glazed unit of
the same quality.
In replacement windows on unlisted buildings,
the loss of historic and detailed fabric is not
recommended, and the original windows should be
retained and repaired wherever possible. If timber
replacements are to be used, then the glazing bars
are either likely to be stuck on to the window, to
retain the narrow detail of the original glazing bar, or
the bar will increase up to twice the width, destroying
the fine attention to detail paid in the design and
construction of our traditional houses. New technology
has allowed manufacturers to explore the use of
double-glazed window panes, rather than using
the whole window. Again, these are limited in where
they will be accepted, as the width of these units still
exceeds the standard single glazed pane by nearly
4 times, resulting in loss of detail on the glazing bar.
Further Information
Further information and advice on windows, their
repair, building regulation standards, and
sustainability can be found at many web-sites.
English Heritage publish specialist technical advisory leaflets which are available free from
www.helm.org.uk.
The Society for Protection of Ancient Buildings
(SPAB) have information on traditional construction
methods, and hold training days and courses for
their members, detail of which can be found at
www.spab.org.uk.
The Forest Stewardship council (FSC UK) has fact
sheets available for downloading from its website
on the use of sustainable timbers through the
construction industry and architects and timber
specifiers, visit
www.fsc-uk.org
The local Conservation Officer may be able to provide
some help and guidance on whether to repair or
replace a window, and any permissions which may
be required.
Additional information on windows, their history, their
repair, and lists of specialist joiners can be found at
www.buildingconservation.com.
When replacing windows in any building, this
needs to be undertaken by someone who is
covered by a Competent Persons Scheme, such
as FENSA - it is also likely that Building
Regulations will be required and it is advised
that the local Building Inspector be contacted.
It is important to note that when working with Listed
Buildings, special consent (Listed Building Consent)
may be required for some works. It is advisable to
check with the Council’s Conservation Officer prior
to starting any such works. If consent is necessary,
a sample of the window, the glass, and drawn
accurate sections may be required as part of any
permission.
Conservation Practice Note 8
Repair & replacement
windows
For further information and advice on the historic
environment you can contact us in the following ways:
Writing:
Wyre Forest District Council
Economic Prosperity and Place Directorate
Wyre Forest House
Finepoint Way Kidderminster DY11 7WF
Email:
conservation@wyreforestdc.gov.uk
Telephone:
01562 732536
This document can be made
available in other languages
(including British Sign Language)
and alternative formats
(large print, audio tape,
computer disc and braille)
on request from
Wyre Forest District Council
by telephoning 01562 732928
or by e-mailing
worcestershirehub
@wyreforestdc.gov.uk
Wyre Forest District Council
Wyre Forest District Council