High quality double glazing serves multiple purposes for a property. It keeps the heat inside the home, meaning that heating bills are reduced. It’s better for the environment because no gas or electricity is being produced, and double-glazing can typically be modified or fitted to most styles of home. It also dramatically cuts out external noise.
Over an extended period of time - and double glazing should last for at least 20 years – the fitting should pay for itself. According to the Energy Saving Trust a flat rated C (in its scale of efficiency) could still save £40-50 a year with double-glazing, while a detached A-rated home could save £120-160. But the initial outlay of at least several thousand pounds will put some people off, meaning that they will never get to benefit from these savings.
Let’s say that it’s just time to change things for the windows of the home. The first place to start is a reconnaissance of the home to assess what needs to be done, and when. More urgent jobs might include various cracks in your windows, rotting frames, and loose fittings. Ask yourself if every room needs to be done at once, or on the flip side, whether it would be cheaper in the long run to get everything done now rather than staggering the job over a few years.
Next, assess exactly what you would like. There’s a great diversity of options available when choosing windows. Secondary glazing – fitting a glass section behind an existing panel rather than replacing everything - might be more preferable for a building where one would like to keep the exterior glass/frame in its current style, such as Victorian or Georgian. For example, it will cost more to install double glazing in a listed building, not least because one would have to gain planning consent beforehand from a local authority.
Triple glazing is another option, although this is not necessarily any more efficient than double glazing. If one has settled on double glazing, there are still decisions that need to be made. Obviously the cost changes with the size of the window, but might also be dictated by the material of the frame: uPVC/aluminium/steel can be recycled, while wood is more environmentally friendly.
Different gap sizes between the glass, the glass type itself (low-emission, etc) and other factors can all dictate the cost. If efficiency is a key concern consult the BRFC.org website, which uses a ‘traffic light’ system to designate the energy efficiency of windows and lists five factors such as air leakage and solar factor.
Essentially then, your material costs could vary tremendously in value, and that’s before we’ve even considered labour and installation costs. This Guardian discussion may give you a greater idea of what to expect. Incredibly, prices varied for a full home replacement by £2-3,000 for the same jobs from different companies. For individual windows, contributors largely paid between £300 and £450 per window depending on the size, but one paid £2,000 for a bay window with stained glass and lead flashing.
The key lesson is that one should obtain a number of quotes, and read reviews on Trustpilot, or perhaps seek advice from Streetlife. Take your time and don’t forget smaller companies, which might be more reasonable than national ones. If all else fails, get thicker curtains or wall insulation.