The detail of traditional joinery is most important to the character of an old building. ‘Off the peg’ modern replacement doors and windows can bear a superficial resemblance to earlier examples but generally they lack the interest of the original in terms of form and detail. Particularly unsuitable are modern units in PVC-U, aluminium or tropical hardwood. Even if they make an attempt at a traditional design they are almost invariably a very poor substitute; typical unsatisfactory details include glazing bars stuck onto plate glass, fanlights incorporated into doors, over-reflective double glazing and imitation sash windows where sashes pivot rather than slide. Contrary to some manufacturers’ claims, there is also evidence that PVC-U does not have a great life expectancy. Timber windows and doors, if properly maintained, can last almost indefinitely.
Similarly old glass, including crown or cylinder types, differs significantly from modern forms. Old glass should be valued for its colour and texture; these factors can make a surprisingly important contribution to the character of windows. Retention of old glass avoids the mechanical, lifeless look that can occur with modern replacement fenestration.
Regular maintenance of traditional windows and doors should include repainting, lubricating hinges and other sliding parts and checking putty to glazing for cracks. If required draught proofing, or secondary glazing, can be installed without harming the fabric of an old window or door.