Energy Efficient Windows – Why Bother?

The two biggest sources of heat loss in a home are windows and the roof.  As the cost of household heating is the largest component of your gas or electric bill then energy efficiency matters.

So, if you have decided that you need to replace the windows in your home then you should consider your options for the replacement.  That’s not to say you must choose the most energy efficient windows available, just that you have the information you need to make the best choice for you.

How can you tell if a window is energy efficient?

Most reputable windows companies will clearly identify the U value of a total Window, from 1.4u A rated Equivulent (most efficient) to 2.6u G (least efficient). 

It is now is copulsory for responsible companies to register your rating through FENSA which Securahome have been members of since its creation in 2002

Securahome's Energy efficient specification is identified through the Brand SecurAtherm no other company can use this brand and this is specific to our sealed unit setup!

So what exactly is an energy efficient window?

All windows have the same basic structure:

• A frame that surrounds the glass
• One or more panes of glass
• A spacer between the panes of glass to keep them apart
• Fittings such as handles

You make a window energy efficient by changing each of these components for ones that are tested to help retain heat.  This means that an energy efficient window will have some (or all of the features below):

• The frame will be made from high performance PVC-U with internal beads and gaskets to minimise heat transfer
• The glass will be “low emissivity” which has an invisible, heat reflective coating to reduce heat loss and for the A rated equivulent windows Soft coat Glass is Used.
• The spacer will be made from materials that contain little or no metal reducing the transfer of heat between the glass surfaces (known as warm edge spacers)
• The space between the window panes may be filled with an inert gas such as argon, to prevent heat transfer.

So what’s the benefit to me?

Right, let’s talk money.  Here the maths can get really, really complicated because how much money you will save depends on lots of things including:

• How many windows you have
• How big they are
• What type of window you are replacing
• What you are replacing them with
• Your current heating tariff and costs

In short, it’s complicated.  However, the good news is that you don’t need an exact answer to make a good decision.  A few, simple guidelines give you all you need to know to make a good choice.  So here it is, in figures helpfully calculated by the Glass and Glazing Federation, compiled by Pilkington:

Of course, these numbers are estimates and yours will be different, but the principle makes sense.  In summary:

• Installing energy efficient double glazing will save you at least £200 per year – which over the typical 20 year life of your windows equates to at least £6,800 (fuel prices will increase but the cost of your windows is fixed now)
• A rated equivulent windows save you about 7% more than the C rated equivalent, and B rated windows are somewhere in between
• Typically, you will save around 10% of the energy bill for your house.

In terms of environmental impact, the figures translate to a saving of between 19 (terraced house replacing double glazing) and 49 (detached house with single glazing) tonnes of CO2 over the 20 year life of your windows.  CO2 is the gas attributed with causing global warming, and enough energy is saved every year to run at least 2 TV’s for the year.

What will all this cost me?

Of course, no two houses are same and no two requirements are the same, but you don’t have to be a rocket scientist to figure that spending a few thousand on windows today will pay you back a comfortably over the lifetime of the windows.  This ignores the fact of course that new windows look better, help create a more comfortable living environment, are more secure and require less maintenance than their older cousins.