
Well-installed double-glazing can make a real difference to the comfort of your home and they can significantly improve the look too, but most window companies do charge a lot for them – so is now the time to consider replacing the double-glazing in your home?
So lets consider the reasons for replacing the windows:
The new double-glazing units will help lower my energy bills
We get about 100 calls about every week “I moved in to my new place last week, I am not sure what I can do to improve the energy efficiency of my home, but I reckon the double glazing could do with being replaced as it is about 15 years old”
Well the truth is that the savings from replacing old double-glazing with new double-glazing are sadly not as much as you would like to think.
Even if you go from single glazing to double-glazing the energy savings aren’t enormous – it still might be a few decades before the windows pay for themselves.
The issue is that even the best double-glazing on the market today is comparatively rubbish in terms of energy efficiency compared to something like 300mm of loft insulation – so the energy savings from going from old double glazing (and believe me 15 years isn’t that old!) to new double glazing is going to save you very little on your energy bills – so in our opinion this is not really a reason to make the investment. You can learn more about u-values of different building elements by clicking on the link below
>>> U-Values of different building materials <<<
If the existing double-glazing is ill fitting (so there are big gaps all around the frame where cold draughts are entering) then there is certainly more of a case to replace it, but even then we would suggest reading on to see if there might be other reasons for replacing the double-glazing to make the investment decision slightly more compelling.
My double-glazing is fogged up – I can’t see!
This is very much linked to the point above, but quite often over time the seals on the double-glazing units unfortunately just give up. This means that the gas that is held between the units that helps minimise the transfer of heat across the unit leaks out. Now unfortunately when this happens air can enter into the void and then condensation can form between the panes of glass.
If this happens then obviously it can ruin your view, so this may be one reason why replacing the glazing might be worth it. If you have a stunning view out of your bedroom window (or you simply want to be able to see out!) then the unit needs to be replaced.
There are DIY ‘re-sealing’ units that you can now buy for double-glazing but unfortunately they cost a lot of money and don’t have long-term results. While in the short-term the condensation within the double-glazing unit may go, give it a few months and it will be back!
My double-glazing is out of style – I want to modernise!
Beauty is in the eye of the beholder and so while some people love their uPVC windows, others will want to rip them out and put in wooden or aluminium frames.
This is a decision that we can’t really help with, although our one line of argument and this is based on working with glazing companies across the capital. It seems more and more people are taking out ageing uPVC double-glazing and putting in wooden framed glazing in its place. The wooden glazing tends to go down well with potential buyers so while we can’t see it will increase house value, it may help get you a sale!
My double-glazing is falling to pieces!
This is one of the most compelling reasons to replace your double-glazing – if they are rotting then it is time to get them replaced! Wood rot not only looks bad, it can actually make the windows unsafe and much like the ill-fitting windows, air can rush through any gaps resulting in your heating system having to work harder during the winter months.
It is just too noisy outside!
It always seems one realises a bit too late when buying or renting a new house but noise from outside can become a real stress. On the whole the bigger the gap between the two panes of glass the better. Newer uPVC double-glazing often now has a 16mm gap compared to the 6mm gap of glazing units just 5-10 years old, so without a doubt there is going to be an improvement in terms of noise reduction. In addition there are glazing companies out there that use noise-reducing, acoustic glass – but obviously there is a premium to pay on this.
The real winner for noise reduction is actually secondary glazing mainly because the gap between the existing window and the secondary glazing panel is so large – triple glazing also might be worth considering.
If you have any thoughts on what we have written, please comment in the comments section below.
I think that secondary glazing would be your best option here. With secondary glazing you can reduce the noise levels by quite a significant amount as well as reducing the heat loss (means less heating bills to pay!) I think that you should get a quote about secondary glazing and price up the cost with the benefits and your mind may be made.
I have old aluminium double glazing, which seems sound, do I need to replace them to save on energy as the metal seems cold to the touch?
Hi Lynne,
The energy savings will be minimal although the new windows would marginally improve the comfort of the room. The cold metal also may be a place where water condenses, so if this is creating problems (mould) then you may want to replace them.
can you just replace the double glazed units with triple glazed units so the frames do not need replacing also?
I want to replace 2 windows facing the road because of noise. Or would secondary glazing be better?
I would sugggest seeing an architect with Passivhaus Enerphit experience to getproper ACDs drawn up as you’ll lose the thermal and acoustic benefit of triple glazing with the standard installation methods that window fitters use. They are not known for building tight and there are usually thermal bridges. There probably aren’y cavity closers and cold air which comes in at the airbrick is probably permeating around the frames which will be evident if the cill and reveals are cold to the touch. If you take the facings off around the frame you’ll be lucky to find insulation filling the void, let alone tightly-fitted solid foam but plenty of arthropods indicating an air infiltration path. Your DG is very likely transmitting sound by the frames rather than through the glazing, external noise also gets in through pipe and waste penetrations as plumber’s don’t usually seal around pipe penetrations, let alone use airtightness grommets eg Pro-Clima Roflex.
Cheaper just replacing the seals. Test for air leaks with a candle, smouldering taper or an incense stick. Wear a dust mask to stop your breath affecting the airflow. Even if draughts ar imperceptible the sum of X metres of imperceptible draught soon adds up. The seal vendors sell sample packs on ebay to assist with matching seals. Try with one DG unit and if there’s a difference When fitting new seals just push them in. Dn;t stretch the seals because they’ll contract again and leave gaps.
Our double glazing is externally beaded. I have been told it is about 25 years old, but was top of the range at that time. Obviously double glazing companies tell you that there is a security risk with these windows. We have large windows and have been wondering if the house would be warmer if we changed them. When is it the right time to change them?