Cold draughty windows?

With the nights getting colder, it is the time of year when we notice how draughty and cold our windows are.  Many of us in South West London are lucky enough to live in period properties but one downside is our single-glazed rattling windows.  Some 10% of your home’s heat is lost through its windows and two-thirds of that is lost through the glass.

Total replacement with double-glazed units is the expensive option but there are other cheaper options you can consider first.

First of all – do you have thick lined curtains or well-fitting lined blinds?  In tests, curtains performed rather well in retaining the heat!  You can try blinds that keep out the light and draughts such as the award-winning BlocOut blinds ( or tuiss (

Another solution is to eliminate as far as possible the air leakage around the frames.  A small gap around the sashes can amount to the equivalent of a tennis ball shaped hole in the window.  Local joiners and specialist companies such as Ventrolla (, Refurbasash ( or the Sash Window Workshop ( will add brush or foam inserts to give a proper seal round the sashes.  Expect to pay from £250 per window and get a couple of quotes. 


Rather than replace old windows, English Heritage would like all period property owners to consider secondary glazing.  Companies such as Selectaglaze ( or Storm Windows ( both supply to grade I listed properties (and if its good enough for the National Trust…).  They may work in some situations and can be good at reducing noise pollution, but they may be awkward if you are using the windows a lot for ventilation – or if you have teenagers who cannot open one window let alone two!

If your windows need more attention than simple draught proofing and you cannot repair any rotten areas (parts of the outside can be easily restored by a good carpenter), you may bite the bullet and replace them.  If you live in a listed property or a conservation area, replacement of old windows can be subject to planning and building requirements – you would need to check your local authority, but many do allow sympathetic replacement of old windows.

Replacing single-glazed windows with high performance glazing (look for low emission and gas, such as argon, filled) will significantly reduce the heat loss.   You may be able to keep your window frames and replace only the glass with the latest slim-line double-glazing: try or for 6mm ultra thin Pilkington Spacia glass (  A good joinery company should be able to fit these into your existing units as long as you have enough depth.

If you are replacing windows, for the smartest look (and most sustainable), use FSC timber or try the latest product Accoya – wood naturally treated to last much longer than ordinary timber.  Local company SPS timber ( supply windows to match your existing ones made from Accoya. Other companies such as Rationel ( will supply both modern tilt-opening windows as well as classic designs which will suit the style of your house.

One final note: every house is different – particularly older houses which have been altered and extended over the years.  Each will have different problems and what will work in one house may not be suitable for another.  Getting good advice from a reputable firm is invaluable.

(From an original article in Time & Leisure, Putney & Barnes edition, February 2014)