If you want to replace or repair a period window you have to scour the small ads for a specialist or try your local joiner. It is a frustrating business, but it may be worth it in the long run. According to a survey carried out by Knight Frank & Rutley, nothing puts buyers off a house more than replacement windows.
Windows are the most prominent features on the face of a house, dominating its external appearance. The survey showed that buyers who wouldn't blanch at a new kitchen or bathroom baulk at the idea of replacing windows. Given the cost of doing it properly, they may be very wise.
One leading agent is currently selling a six-bedroom Victorian house with a good garden in a popular part of the Home Counties. This is the kind of house purchasers are queuing to buy, yet they were invariably put off by the picture windows. One potential purchaser went as far as getting a quote for replacing them all. It came in at over pounds 25,000.
It is easy to see why some people have opted for plastic. UPVC windows need very little maintenance, do not warp and are cheap. They are also, normally, double-glazed, a feature which is rising up the list of buyers' expectations. It shouldn't be, according to John Fidler of English Heritage. He says people who want to cut their heating bills would do better to invest in draught-proofing or a heavy set of curtains. "The energy experts at the Building Research Establishment say that double-glazing is not effective," Mr Fidler said. "The capital cost of double glazing when compared with the energy savings per year may take up to 25 years to repay."
The "greenest" house builders go for triple glazing, but they put it in wooden frames. This is partly because it is more ecologically sound and partly because they believe wood is better. Scandia-Hus, the Scandinavian firm that specialises in energy-saving new homes, uses a high quality softwood timber from Sweden for its triple-glazed windows. "The wood is far better than anything you can get in England apart from oak trees," said Mike Mapston, the technical director.
He added that they got a higher efficiency rating using wood than UPVC, partly because of the quality of the glazing and partly because of the air-tight seal between the window frame and the house. But aesthetics and environmental awareness were also part of the equation. "Timber has been shown to be the most environmentally friendly material there is," Mr Mapston said, "and in our houses, it looks right."
Most people prefer wooden frames for aesthetic reasons. Tony Salter put in new French doors at the back of his Edwardian terrace in Dulwich, south east London, using the Original Box Sash Window Company. "They made them exactly as they had been originally," Mr Salter said. "They even found a firm in America that produced the particular type of patterned glass. The doors were one of the main factors when we came to sell the house. They tipped the scales in our favour."
The Original Box Sash Window Company was started in 1984 by John Rose, who saw a gap in the market. Mr Rose had been made redundant from an architectural practice and was selling double glazing. "People were saying it was a shame they couldn't have their box sashes done," Mr Rose recalls. "There was no serviceexcept the odd corner joiner."
His company now employs 70 people from its base in Windsor. They produce near perfect replicas of a property's original windows, but with double glazing and their own draught and dust exclusion system, Sashseal. This kind of work does not come cheap. It costs roughly pounds 1,000 to replace one full sash window.
For even older properties the number of experts available decreases with the centuries. My colleague Duff Hart-Davis recently described replacing some windows in his 16th-century Cotswold stone farmhouse. He had the good fortune to come across Michael Waddingham, an architect who has developed a very slim double-glazed window in a black metal frame with antique catches. With the walls of Duff's farmhouse more than two feet thick and rotten lintels needing to be replaced, the bill for six windows has been pounds 20,000.
If your house is old, however, it may be possible to get an improvement grant for such costly but beautiful alterations.
Where to get help
Many period houses are in Conservation Areas. The local authority conservation officer is a good source of free advice on local craftsmen and grants and has powers to stop ugly alterations.
Most towns or counties have a historical society. Michael Waddingham found the one in Stroud, Gloucestershire to be an astonishing source of knowledge.
If your home is listed you will need Listed Building Consent for window alterations.
The Original Box Sash Window Company, The Joinery, Unit 10, Bridgewater Way, Windsor, Berks SL4 1RD; 01753 858196.
The London Crown Glass Company supplies glass for period buildings. Its customers include the National Trust and English Heritage; 01494 871966.
Ventrolla, based in Harrogate, but with franchises elsewhere, specialises in renovating and draught-proofing old windows; 01423 567004.
John Fidler of English Heritage is organising a conference, 'Framing Opinions', at Fort Brockhurst, Hants, in February. Call 01705 580068.Reuse content