Home > In the Home > Double Glazing vs Secondary Glazing

Double Glazing vs Secondary Glazing

By: Scott McBride - Updated: 29 Dec 2012 | comments*Discuss
 
Double Secondary Glazing Save Energy

Both double glazing and secondary glazing can save energy by reducing the amount of heat lost through windows. The more effective is double glazing, which works by trapping air between two panes of glass, creating an insulating barrier. It cuts heat loss in half and also reduces noise and condensation. Installing double glazing can knock up to £100 a year off heating bills and reduce a household's carbon dioxide emissions by three-quarters of a tonne, but fitting it is a professional job and can be expensive.

For those on a budget, secondary glazing could be the answer. It costs less than double-glazing and will still reduce heat loss and draughts, although the savings will be around half of those achieved by double glazing. Secondary glazing works by installing supplementary glazing on the inside of an existing single-glazed window. No planning consent is required and it can provide a solution for listed buildings or homes in conservation areas if replacing existing windows is not a practical option.

Secondary glazing shouldn't prevent windows being opened easily for ventilation, but can restrict escape in an emergency, so it may be best to leave one window untreated. In summer, secondary glazing may not be wanted, particularly if it restricts the opening of windows. It can be taken down, but will need to be stored. When fitted, secondary glazing should be draught stripped, but to prevent condensation the original window frame should not be.

Mind the Gap

To get the best from double glazing or secondary glazing, the gap between the two panes of glass should be two centimetres. A smaller gap leads to greater heat loss and a larger one makes little difference to the level of thermal insulation. Using argon gas within sealed units instead of air is another energy saver. Argon is an inert gas, which has better thermal properties than dry air.

Other considerations have to be taken into account, such as which type of glass should be used. Low emissivity glass, often called Low-E, is more energy efficient thanks to a microscopically thin coating on one surface of high-quality glass. The clever coating reflects long wavelength heat from radiators and room surfaces back into the building, but allows in short wavelength solar energy, making good use of the sun's heat.

Clear Difference

Low-E looks identical to ordinary clear glass and the coating is almost invisible. It reduces condensation, so frames and surrounding surfaces need less maintenance, and where extra safety or security is required, Low-E toughened or laminated glass can be used. Double glazing with Low-E glass is as energy efficient as normal triple glazing, without the extra weight, and Low-E can be used in secondary glazing too.

A less straightforward question is whether to choose uPVC or timber frames. Wood double glazing can cost up to three times as much as uPVC and there are environmental pros and cons for both. While uPVC windows can be recycles, the reality is that, in Britain, very few are. Wooden frames can cause environmental threats too, however, as they need to be painted and at the end of the window's life that paint will end up either in landfill or an incinerator.

You might also like...
Share Your Story, Join the Discussion or Seek Advice..
Why not be the first to leave a comment for discussion, ask for advice or share your story...

If you'd like to ask a question one of our experts (workload permitting) or a helpful reader hopefully can help you... We also love comments and interesting stories

Title:
(never shown)
Firstname:
(never shown)
Surname:
(never shown)
Email:
(never shown)
Nickname:
(shown)
Comment:
Validate:
Enter word:
Topics
Latest Comments
  • Evo3
    Re: New Build Grants and Funds
    Hi I’m wondering if someone can help me. I’m looking to see if there are any grants available to help with building a few different…
    20 February 2020
  • Red Dog
    Re: What is the Equivalent Wattage for Energy Saving Bulbs?
    I like a very bright light in my living room as a dim light gives me headaches and depression,…
    9 February 2020
  • JULIE
    Re: New Build Grants and Funds
    hi i am building my own house it is going to be a farm house can you tell me if there are any eco grants out there to help me go…
    5 February 2020
  • EcoGreen Organics
    Re: Grants Available For Your Business
    Hello, we are looking for equity partners for the Waste to Energy Project in Zambia.Waste to Energy Project is based on…
    1 February 2020
  • rach
    Re: Eco-School Grants and Funds
    Hi, there seem to be no links to suggest where this funding is available from. Can you help point towards application forms etc.…
    30 January 2020
  • LEL
    Re: Eco-School Grants and Funds
    I’m making enquiries regard above information on behalf of St Christopher School Codsall, Wolverhampton. In particular garden…
    23 January 2020
  • peter
    Re: Eco-Community Groups
    Hi, We are looking for funding to improve the insulation on our community based social club, we host a varied selection of community based…
    13 January 2020
  • Glo h
    Re: Eco-Community Groups
    Hi I own a small food business, I was wondering if you could help me with a grant to go biodegradable I have done some changes its just so…
    8 January 2020
  • Stacey
    Re: Are There Any Grants for Water Treatment Systems?
    Hi is there any kind of help that you can with a new drainage system all around the house my drainage…
    21 December 2019
  • Jase
    Re: Grants Available For Your Business
    Hi I am looking to bring a eco friendly building material to the UK. Then mass manufacture it and ship national. The…
    15 December 2019