Choosing and buying double glazing

It’s a sad truth that the double glazing industry is tarnished with a less-than-wholesome reputation: high pressure sales tactics, unethical contracts, shoddy workmanship. In this article we look at the ways you can protect yourself from the tricks of the trade plus how to get the best quote and the best workmanship.

Choosing and buying double glazing

Choosing and buying double glazing

Top tips:

  • Use suppliers that have been approved by schemes such as the Double Glazing & Conservatory Ombudsman Scheme (DGCOS) or the Fenestration Self- Assessment Scheme (FENSA).
  • If in any doubt that a double glazing supplier is ethical visit the Double Glazing & Conservatory Ombudsman Scheme
  • If buying double glazing on finance be absolutely sure of the APR and the total amount you will end up paying
  • PVC isn’t kind to the environment so if your budget stretches to FSC approved timber go for it!
  • If a double glazing salesman offers you a ‘today-only’ deal, turn it down

How does double glazing work?
Double glazing works by essentially sandwiching a thin insulating layer of air or an inert gas like argon between two panes of glass. This insulating layer acts by preventing heat transfer. Secondary glazing involves adding a second sheet of glass to the frame but isn’t quite as effective as double glazing

What are the benefits of double glazing?
A key benefit of double glazing is the saving on your energy bills. Let’s say you swap the single-glazed windows in your three-bedroom home with double glazing. According to Which? you’ve just saved yourself £135 off your annual heating bill. For more advice read our feature on insulating your home.

You’ll also reduce your carbon footprint: an estimated reduction of 720kg of carbon dioxide emissions from the same three-bedroomed home. And not only that you’ll also reduce outside noise, a key consideration if you live in a road with lots of passing traffic.

There’s also the security factor. Remember, thieves will always look for the easiest way inside a house: modern double-glazed windows tend to be much more secure than older windows.

How do I go about getting a quote?
Ask neighbours, friends and family to recommend good local double glazing companies in the area. Smaller local companies are less likely to use the aggressive sales techniques of the nationwide big boys, such as calling the head office for a bigger discount.

In 2010, a new Double Glazing & Conservatory Ombudsman Scheme was set up as an independent regulatory body for the double glazing industry. All its members go through a 12-point vetting process covering public liability insurance, guarantees, references, etc, to protect customers. This is a great starting point for securing a quote. Which? Local and Check-A-Trade will also tell you if a company is a recommended installer.

It’s always good practice to get quotes from three different double glazing companies to give you a good idea of the range you should be paying. There’s no harm in letting each company know you’re seeking competitor bids.

How much will double glazing cost me?
Some national companies have been known to drop their original quote by as much as half, so establishing a clear price tag can be a tiresome process. If we return to the example of our three-bedroomed house, the average cost will be between £350 and £400 per window, based on the assumption that eight windows will be installed at once.

What are the rules and regulations for installing double glazing?
In England and Wales all new and replacement windows must conform to the following energy efficiency requirements:
U2.0 for wooden and PVC frames
U2.2 for aluminium frames
Schemes such as FENSA and DGCOS allow their members to self-certify that work complies with Building Regulations. When you come to sell your home you may need to supply this certificate so do keep it safe.

I live in a listed building. Can I upgrade my windows to double glazing?
Original windows are key to maintaining the appearance of conservation areas so not surprisingly councils don’t take kindly to plastic windows in period properties. They’re more likely to grant planning permission for timber sash and casings but be warned these are not cheap; as a general rule of thumb about £1,000 per window. An alternative is to restore the originals and install secondary glazing, instead. Remember you still need to seek permission even for secondary glazing.

How do I best maintain double glazing?

  • Keep your room well ventilated to avoid the build up of condensation on the inside of the windows. If you notice condensation between the panes of glass it means the unit is faulty in which case you should contact the installers
  • Vacuum frames, openings, screens and seals to avoid dirt building up and damaging or discolouring your windows
  • A vinegar and water solution will keep your windows super-sparkly and is kind to the environment too.