Replacement Windows
Windows
are
the eyes of a building – its most important feature. Altering them can easily spoil not just the building
but the character of an area.
Altering windows can change the whole appearance of a property. Done unsympathetically, this will affect not just its character but the financial value of the property. Buildings which retain their traditional appearance are increasingly sought after. Most existing windows can be repaired. Too often they are needlessly replaced.
There are various types of traditional window within the National Park. Their design, material and method of opening have all varied over the centuries. Generally speaking, any one style of building calls for one type of window. It is not possible to 'mix and match' across styles without spoiling a building's character. Most types of modern window are only appropriate in modern buildings. They will almost always look wrong in old buildings.
The advice is always to:
- Retain original windows, repairing wherever possible
- Renew, if necessary, with exact replicas
- Avoid modern-style windows
- Avoid double glazed windows
- As an alternative, draught strip existing windows or add secondary glazing.
Repair
Repairing original windows is the best way of conserving the character of the building. It retains historic fabric, not just the joinery but also the original glass. In most cases the timber is of better quality than today's softwood replacement. It is often only the bottom sill and lower portions of the side frames which tend to rot and therefore need replacement. Properly repaired and maintained original windows can give service for 100, 150 or 200 years. Such windows are more cost effective in the long term than replacement with modern alternatives.
Renewal
Where replacement is unavoidable, the new window should be an exact copy of the original. This means not just the same design, material and method of opening, but the same mouldings and thicknesses for frames and glazing bars. It is particularly important that the glazing bars are no thicker than the originals – usually about 18mm.
Alterations and additional windows
Using a modern style of window is not appropriate in historic buildings. New windows should:
- Open in a traditional manner – i.e. sash or side hung casements for houses; occasionally, inward opening hoppers in agricultural buildings. Top hung, outward opening lights, louvres or pivot windows are not suitable.
- Be subdivided in a traditional manner – this generally means each individual pane is related to the proportions of the window as a whole. (The number of panes is related to the age of the house.) Unsubdivided or poorly subdivided windows are not acceptable.
- Be traditionally detailed i.e. with flush frames not storm proof detailing in the case of side hung casements, and with correctly profiled mouldings to the frames and glazing bars.
Finishes
To retain their historic character, windows should have a paint or opaque finish – preferably white or off-white, as these tend to be the predominant colours. A transparent brown timber stain is not appropriate on historic houses – it looks too modern.
Glass
Old glass, traditionally crown glass, has a sparkling reflective quality entirely lacking in modern glass with its uniform, flat appearance. Wherever possible, original glass should be saved for reuse. It adds considerably to the attractiveness of a property. Some specialist firms now produce glass specifically for use in historic buildings.
Double glazing
Please think twice before replacing windows with double glazed units, whether in UPVC, aluminium or timber frames. The sizeable investment needed for such replacements is rarely reflected in the value of the property. Installing such windows in an historic building can in fact reduce its value.
There is growing evidence that UPVC or aluminium windows are not cheaper in the long run, despite the maintenance-free claims made for them. If they do fail, such windows cannot be repaired.
Old buildings need to 'breathe'. Eliminating all draughts can lead to condensation problems in hidden parts of the structure. Ecologically, the use of UPVC in particular, is damaging both in terms of the energy needed for manufacture and the problems associated with its disposal.
It is possible to achieve improved thermal insulation and reduce draughts by overhauling and upgrading existing windows. Specialist firms can provide some of the advantages of double glazing without the expense, disruption and damage to the character of the property. We can offer information on such firms.
Adding
secondary glazing is another option which in historic building terms is preferable to double glazed
units. Secondary glazing is also a more effective way of providing sound insulation, because of the
wider air gap between the two sheets of glass.
The last argument against
double glazing is of course the aesthetic one. The material, frame sizes, mouldings, glazing bars and
glass will all look wrong in an historic building. Government design advice states clearly that: "UPVC
windows are almost always unacceptable" (Appendix IV, Circular 8/87).
The Authority is likely to refuse all applications to install UPVC windows in listed buildings.
Permissions
If
your property is listed, then Listed Building Consent is needed for any alteration to the existing windows.
Changing the material, from timber to UPVC for instance, is an alteration which requires consent. If
your property is not listed, depending on its use you may require planning permission to alter the windows.
You should check with the planners in the Planning Service of the Authority. If you are replacing
windows then building regulations approval will be needed from your District Council. For further information
see 'Building Regulations and Windows' (61KB) 
.
Grants
Grants
are available to the owners of listed buildings, or historic buildings within conservation areas, to
help with the repair or renewal of traditional windows. Higher percentages are offered for repair rather
than renewal, and for restoration – where the existing windows are inappropriate and in a sound condition.
Grants for repair and restoration
Further advice
If you would like further advice on any aspects of traditional windows please contact the Historic Buildings Team. We have lists of specialist joiners and leaded light manufacturers and are glad to offer design advice on the design or repair of windows on your property. If your building is not in the National Park please contact your local authority.
The Historic Buildings Team is:
John Sewell - Historic Buildings Architect email: john.sewell@peakdistrict.gov.uk
Sue
Adam - Conservation Officer email: sue.adam@peakdistrict.gov.uk
Catherine
Mate - Conservation Officer email: catherine.mate@peakdistrict.gov.uk
Rebecca
Waddington - Conservation Officer email: rebecca.waddington@peakdistrict.gov.uk
Peak District National
Park Authority
Aldern
House, Baslow Road, Bakewell, Derbyshire DE45 1AE
Telephone:
01629 816200
