Energy & Sustainability

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Double Glazing: the Pros and Cons

22nd July 2022

Double glazing helps to keep your home cool in the summer and warm in the winter. If you are considering investing in double glazing, or updating your existing, old double glazing, check out this series where we go through the advantages, followed by the disadvantages.

The advantages of double glazing

Double glazing clearly offers many advantages to residents in comparison to traditional single-glazed windows. The primary benefit is that the extra layer of glass acts as an insulating layer, meaning that less heat can escape through the windows, and less cold air can find its way in. Double glazing acts as an insulator to the home by trapping air between the glass panels – as air is not a good conductor, the extra layer of trapped air prevents the warmth from travelling from the outside in (or vice versa). Therefore, as a direct result of double glazing, bill payers will see an instant reduction in utility bills; something that is much needed in the current financial climate.

Another benefit of double glazing is noise reduction. This is especially valuable to households that are situated in cities and suburbs, where noise from passing traffic or highly populated streets can be a problem.

The disadvantages of double glazing

Double or triple glazing undoubtedly has several benefits, however it does have some downsides that it is important you are aware of, too. In the first instance, if you are replacing existing single-glazed windows, double or triple glazing will cost a lot more than a simple like-for-like replacement. However, with the savings in heating bills, that investment should pay for itself over the years. If you have an older property or live in a listed building, standard double glazing is unlikely to be in keeping with the aesthetics of your home. This means that you will have to pay more for wooden frames or a style that suits your building; in the case of listed buildings, it is likely that you won’t able to install double or triple glazing at all.

Aside from the cost, if appropriate ventilation isn’t installed, double glazing can lead to condensation and mould in the home. This is because it restricts the airflow. Newer homes which have to have good quality double or triple glazing installed as standard have adequate ventilation, but older properties which were not made for double glazing may not. This is not a disadvantage as such, but it is something to be aware of when installing your double glazing and when choosing who will install it for you.

With energy prices continuing to rise, it is worth evaluating your double-glazing options now, when local double-glazing specialists might be less busy, and the weather makes installing new windows a simpler job. For more tips and advice, follow us on Facebook or Twitter.

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That said, roof orientation, shading, your energy usage, and how long you plan to stay in the property all affect whether the numbers add up for you. It's worth getting a few quotes and running the figures before committing.
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Are there government grants available for home energy improvements?

Yes. The main ones right now are the Boiler Upgrade Scheme (for heat pumps), the Great British Insulation Scheme, and ECO4 (for eligible households). The details change regularly (eligibility, grant amounts, and which schemes are active) so check directly on GOV.UK or with your energy supplier for the current picture. Just bear in mind that installations need to be done by accredited installers for the grant to apply.
How do I know if my home has adequate insulation?

High heating bills for the size of the property, cold walls and floors, condensation on internal walls, and draughts around loft hatches and window frames are all signs that heat is escaping. A professional energy assessor can survey the property and identify exactly where the losses are happening. Your Energy Performance Certificate (EPC) - if it's up to date - also gives you a useful starting point.
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Most come with a 25-year performance warranty guaranteeing at least 80% of rated output - and many systems outlast that. The panels themselves have no moving parts, so they're low maintenance by nature. The inverter is the component most likely to need replacing, usually after 10 to 15 years. Rain generally keeps panels clean in the UK, but a professional clean every couple of years is worthwhile - particularly on low-pitched roofs where debris builds up.
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Why might solar panels not be right for my home?

There are a few things worth keeping in mind that can affect whether solar panels make sense for your home. A north-facing roof receives less direct sun and will generate considerably less power, and significant shading from trees, chimneys, or neighbouring buildings can also have an impact. Some listed buildings and conservation areas have planning restrictions, so it's worth checking before going too far down the line. Homes that need re-roofing soon, or that have existing structural issues, may also face additional costs that change the overall picture. And if your household electricity usage is quite low, the payback period can extend more than you might expect.

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