Replacing timber windows and doors in conservation areas
October 24, 2023 | Blog
The first conservation areas were identified in 1967 and today there are over 8,000 conservation areas in England, designated for their special architectural and historic interest. These areas are an important part of the UK’s Heritage. The unsympathetic replacement of windows in these areas was found to be the single biggest threat to property values in a national survey of estate agents conducted by English Heritage.
The ‘Heritage at Risk’ campaign launched by Historic England, on conservation areas raised the loss of traditional windows as a cause for concern, stating that unsympathetic replacement of windows and doors represented the number one threat to our heritage and affected no less than 83% of conservation areas. At Bereco, we believe in embracing the future, yet at the same time preserving and protecting our past. We are able to do both with our comprehensive range of Heritage timber windows and doors.
“Valued objects and qualities such as historic buildings and cultural traditions that have been passed down from previous generations”.
This is one of the many definitions of the term ‘Heritage’, which is the premise for the design of Bereco’s Heritage Range which has been delicately designed to stay true to historic original window designs whilst, at the same time, offering u values as low as 1.3W/m²K.
With windows and doors in the range including flush casement, sliding sash windows and flush french doors, available in both single and 14mm SlimLine (narrow cavity double glazing), Bereco really have a solution that both Conservation Officers and Building Inspectors can embrace, and one which allows sympathetic replacement and preserves our heritage.
Achieving planning consent the simply way.
Achieving planning consent where a listed property is concerned or wherein a conservation area can often be daunting and lead to a drawn-out process. With many years of experience in planning restrictions and planning authorities across the UK, Bereco take the hassle out of this process by providing a range of services to their network of approved installers.
Services such as window samples for planning consent, a package of scale design and section drawings, expert advice on solutions such as the appropriate glazing and matching specific original design details.
Careful consideration should be given to the replacement of any windows in a conservation area. One such consideration and area of debate amongst conservation departments is the glazing bars or astragals as they are sometimes known and if a ‘plant on’ replica glazing bar should be accepted.
Retaining Traditional Design with Plant on Bars
From the 16th century, glazing was most commonly divided by lead in the form of diamond-shaped leaded lights. From the 17th century onwards rebated timber glazing bars began to be used with early glazing bars often around 40mm thick to support the fragile glazing of the time. As glazing improved, glazing bars were introduced some as thin as 12mm and lambs’ tongue and gothic designs were founded.
In the late 20th century double glazed units were introduced to improve the thermal performance of windows. These units can now range in thickness anywhere from 14mm (narrow cavity) up to 40mm (acoustic & triple glazed units) and as a result glazing rebates within windows have had to be increased to accommodate such thicknesses and weights of glass. Poor glazing practices led to the condensation of sealed units, water ingress around individual panes of glass and early deterioration of timber sections. To avoid these issues, a more robust method of glazing was required and the drained and vented method was introduced. This method, incorporating weep holes that allow water to drain away has a design that dictates that glazing bars must be a minimum of 45mm to 50mm in thickness to accommodate the glazed units.
In order to overcome these challenges and offer a glazing bar more sympathetic to the ovolo and lambs tongue slim designs of the past, a ‘plant on bar’ was introduced. This method of glazing allows slim glazing bars as thin as 16mm and allows water runoff without the need for a drained and vented glazing system. The Bereco Heritage Range incorporates a range of stick-on bar designs from 16mm to 25mm, right up to 35mm. For a traditional appearance, this incorporates a back to back spacer bar within the sealed unit to further imitate the appearance of a traditional solid through glass bar.
Bereco conservation solution
Bereco believe in balance, a balance between the longevity, historic accuracy and the energy efficiency when replacement windows are needed in a property of historic importance. Plant on or imitation bars offer that balance between the traditional aesthetics of glazing bars and today’s high performance requirements. Bereco have used the ‘plant on’ or replica glazing bar system since they began manufacturing timber windows and doors over 15 years ago with our windows featuring in over xx conservation areas around the UK.
Bereco are experts at solving intricate conservation details and do so regularly for approved installer CWM Cirencester Ltd.
“We have had the pleasure of working with Bereco for our timber windows now for several years. With Bereco, as a customer of ours recently said, ‘you get what you pay for’ excellent quality, beautiful finish, brilliant service.
Having their warranties means cover for our customers in the years to come and peace of mind for us. Personally, I enjoy working with Bereco because they are always there for advice about products and even to help with supplying the local planning authority scale drawings, along with the knowledge that with every window I order means I am doing my small part for the environment.”Gary at CWM
Bereco continue to champion the restoration and preservation of our country’s heritage as their repertoire of conservation and listed properties continues to grow. Recent projects include the refurbishment at the Historic England Grade II listed Former Post Office in Colchester, the Grade II listed Thrum Mill that featured on Channel 4’s Restoration Man, and the multi-million pound restoration and refurbishment of The Grade II listed building 55 Colmore Row in Birmingham that has been recognised at the British Council for Offices (BCO) Midlands and Central England Awards by picking up the award for ‘Best Refurbished/Recycled Workplace’ and will go on to be judged in the national awards in London later this year.
“These are the projects we really enjoy being involved, we have great a responsibility to the preservation of the heritage in our architecture and seeing these properties being brought back to life gives us a real sense of pride to say we were involved in doing so”Nicola Harrison General Manger
Bereco offers a comprehensive range of Heritage timber windows and doors, perfect for replacing timber windows and doors in conservation areas. With our expertise in intricate conservation details and a track record of projects in many conservation areas around the England, including recent projects in Colchester, Birmingham, and more, we are dedicated to preserving our country’s heritage. If you’re looking for high-quality timber windows in London and elsewhere in England, check out our selection of Bereco flush casement windows with a monkey tail handle.