Custom-made manufacturers of joinery can replicate the original design of the windows in your property and, if these windows no longer exist, can use those in the neighbouring properties or those shown in old photographs to inform the design of the replacements. Details such as the style and section size of the glazing bars, the use of mouldings, the style of the horns on sliding sash windows and the use of traditional weights and cords and the style and finish of the ironmongery can all be incorporated within the design.

In the terraced cottage in Lewes shown below, the property was located within the Conservation area of the town and single glazed replacements were the preference of the property owner and the Conservation Officer. To improve thermal efficiency and enhance privacy and security, double sets of timber shutters were designed and fitted to all of the windows.

Replacing windows in historic buildings

Undoubtedly we all recognise the need to conserve the natural environment by reducing heat loss. This presents an ethical dilemma for architectural conservationists and homeowners alike as a balance needs to be struck between the requirements for energy efficiency and the preservation of our architectural heritage.

Replacing any window in your property now requires Building Regulations approval from your District Council, even if a like-for-like replacement is being made. Where the existing windows are beyond repair and require replacement, it may be possible to incorporate double glazing into the replacements without significantly compromising the character and appearance of the building. Where the existing design does not have fine glazing bars, sashes in both casement windows and sliding box sash windows can be glazed with 24mm K glass double glazed units. Where there are fine glazing bars, 24mm double glazed units with inset spacers and stick on glazing bars can be used to replicate the original design or, alternatively, slimmer 14mm Krypton filled double glazed units will achieve higher U values than the 24mm alternatives.

Conservation Areas and Listed Buildings
Listed buildings are protected by law and it is necessary to obtain listed buildings consent by making an application to your local council to change the design, method of opening or material of the window. As a general rule, Listed Buildings consent is rarely given for replacement double glazed windows in listed properties even when the windows are to be constructed to replicate the originals. Compensatory measures can be taken to increase energy efficiency in other parts of the building such as roof or floor insulation or, with the windows, to fit shutters, thermally line curtains or install secondary glazing. Further information and advice about renovations and alterations to Listed Buildings can be obtained through the Listed Property Owners’ Club at www.listedpropertyownersclub.co.uk.


Replacement windows in a listed property in Wivelsfield Green

For properties located in Conservation areas, permission for aesthetic and functional changes rests with your local Conservation Officer and their advice should always be sought prior to the installation. They will advise on whether a Planning Application is necessary. In either case, a Building Notice application is a requirement and should be made in addition to other consents. Building Control monitor building work to ensure that it meets safety requirements and is up to permitted standards and they will inspect the windows prior to their replacement and follow up with a further inspection after the work has been completed. They will then issue a certificate of compliance which will be required when you sell your property. A charge will be made for this service which is usually a percentage of the cost of the building work. If you are permitted to replace your windows with double glazed alternatives a FENSA regulated company can self- certify their own work and a Building Notice application will be unnecessary.

Building Regulations and FENSA
On the 1st April, 2002, the replacement of windows and doors came within the scope of the Building Regulations for England and Wales and, therefore, any replacement of windows and doors in your home are subject to the requirements of these regulations.

In order to meet your commitments under the Building Regulations you can:

1. Apply for approval to replace your windows and doors through your Local Authority or Building Control Department for which there is usually a charge calculated as a percentage of the project cost

or

2. Use a manufacturer/installer who is registered with FENSA, for which there is usually no additional charge

The FENSA scheme, set up by the Glass and Glazing Federation with the co-operation of the Office of the Deputy Prime Minister, enables registered businesses, like Parsons Joinery Ltd., to certify through FENSA that the design, manufacture and installation of their windows and doors complies with current Building Regulations. Parsons Joinery Ltd. will report your installation to FENSA who will register your installation electronically with your Local Authority and send you a certificate to confirm compliance. This document could form an important part of your Home Information Pack when you sell your property.

FENSA registered businesses are required to understand the Regulations and be capable of installing a product in your home which meets these requirements. They will be in a position to advise you on the design and installation of windows and doors in your home to ensure compliance and thus avoid problems which may occur when you eventually sell your home.