Q: We have bought an old house and the windows are all single glazed and need upgrading. PVC frames would look wrong. What are my options?
A: It your old house is a listed building or in a conservation area you may find your options limited. Check with your planning department first to see if there will be any restrictions. English Heritage are not happy for any alteration that replaces the original windows with modern replacements and in that case you may have to fit secondary glazing inside the existing window pane which usually have large air gap and allow opening for opening the original window or to allow cleaning. Though secondary glazing will give you the energy efficiency you want, the system also does take up quite a space on your window sill and is not particularly convenient to open or clean. You will also need to make sure that any gaps in the old window frames are stopped as if cold and damp can permeate into the secondary glazed space; this will make it less efficient.
Even if there are no restrictions you will want to fit windows to match the age of your house. Nowadays there are double glazed units available to match earlier periods including sash windows and mock Georgian. These can be made from hardwood, so matching more nearly the style of the originals. The best thing to do, as this is not only a considerable investment – but also makes so much difference to the appearance and value of your house is to take advice on the variety of options open to you from experts such as SEHBAC.