woman sitting on windowsill

Whether you have an older home with windows that are beginning to deteriorate or are in the process of designing a new build, there are many situations which will require you to investigate into the efficiency of windows. If you are yet to step into the world of energy efficiency and rated products, then it can be a little daunting to know where to start. Should you invest only in those with the highest efficient ratings or could you possibly go down a few categories to save extra cash? Will investing in better efficiency offer a return? These are all essential questions, and with our guide to understanding energy efficiency windows, you will not only be able to find answers but also begin shortlisting products.

A Guide To Understanding Energy Efficiency Of Windows

With more than 15 years of experience installing windows in Aylesbury and the local surrounding areas, we have seen the dramatic increase in the importance of efficiency. Along with the benefit of providing a more environmentally friendly solution, opting to equip your home with products will also reduce your energy bills and offer better durability. The constant introduction of new technology means that home improvements are more advanced than ever, and windows play a key role in creating a modern home with minimal heat loss.

Nevertheless, if you have not replaced your windows in many years or are new to property renovations, then knowing how to decipher energy rating and choosing the right window types can be tricky. To give you a helping hand, we are going to be answering the following questions:

Wall Of Windows

What Are Window Energy Ratings?

As we are all now actively encouraged to reduce our carbon footprint, manufacturers have made it easier than ever to select products which boast energy efficiency. This also applies to windows, which are now all equipped with a rainbow efficiency label that determines which category they fall into. As always, the label rates products from A+, which is the most efficient, to either E or G, depending on which scheme the windows are registered with, which refers to the least efficient models. This rating takes into consideration several factors from the frame material to the glass type, meaning that it covers the window as a whole. Although any energy rating scheme will give you an insight into the efficiency of your chosen windows, we would suggest investing in those which have been assessed by one of the following:

If you have modern windows, then along with the overall efficiency rating, you are also likely to find a section of other labels. These relate to the following:

  • U-Value/U-Factor – Both of these terms mean the same thing and are used to measure the windows rate of heat transfer. The typical rating will fall between 0.25 and 1.25, and in this instance, the lower the rating, the better.
  • Visible Transmittance – If you live in a location that attracts sunlight, then you will want to pay careful attention to the visible transmittance rating as this refers to the amount of light that your windows allow through. For those who prefer lots of sunlight streaming in, a higher visible transmittance will be ideal and vice versa.
  • Condensation Resistance – Condensation on windows can come alongside a wealth of issues, not only to the condition of your home but also the health of those living inside. It is for this reason that the condensation resistance rating is vital, which measures how much moisture will be able to build up. This is measured between 1 and 100 with the ideal figure being as close to 100 as possible.
  • SHGC – Used to measure the amount of solar radiation that your windows allow into your home, the SHGC (Solar Heat Gain Coefficient) should fall between 0 and 1. If you live in an area that traps the sun, then you will want to invest in a lower SHGC rating.
  • Air Leakage – In order to retain heat, your windows must be airtight. To ensure this, you can use the air leakage rating, which assesses how much air is able to pass through the window. Typical ratings fall between 0.1 and 0.3 with the lower option, the more favourable.

Energy Efficiency Rating

What Are The Signs That My Windows Are Not Efficient?

If you do not remember the last time that you replaced your windows or you have recently moved into an older home, then it is highly recommended to check whether your windows are efficient. Depending on the age of the windows, they may not be labelled with a rating, which means that you will need to keep an eye out for the most common signs of inefficiency. Some are visible, and others are trickier to spot, including the following:

  • Draughts – There is nothing worse than feeling a cold draught in your home, and the main culprit for this is inefficient windows. The easiest ways to determine whether draughts are coming from your windows is through the candlelight test. Light a candle and carefully move it around your window frames. If the flame flickers, then you have found your draught.
  • Moisture & Mould – As mentioned above, a build-up of condensation can prove potentially dangerous. Moisture around the frame or mould forming on the surrounding walls and windowsill are sure signs that your windows are allowing heat to escape.
  • Single Glazing – Having specialised in double glazing in Milton Keynes and the surrounding areas for many years, we cannot stress the importance of making sure that you upgrade any single glazed windows. This is guaranteed to have a negative impact on your home’s efficiency as they provide virtually no insulation.
  • Damaged Seals – It isn’t uncommon for the sealant around your window frames to begin cracking with age, which will allow draughts to seep in. While this can be quickly resolved by resealing the window, if this is something that you find yourself having to do every year, it would be far more efficient to replace the windows altogether.

All of the signs mentioned above are key indicators that you should consider scheduling a window replacement. Depending on the condition of your windows, you may be able to do this in stages, beginning with those that are the least efficient, which will allow you to spread the cost.

Condensation On Windows

How Do You Choose The Right Energy Efficient Windows?

If you have noticed that you are experiencing one of the above signs of inefficiency and are planning a replacement, then it will be important to familiarise yourself with how to choose the right windows for your home. The first step will be to determine which window style you like the most, and then you can move onto ensuring that the products you install are designed with efficiency features. Luckily, there are now a number of different window styles to choose from based on your appearance preferences and property type. For example, those with a modern new build home are likely to prefer casement windows as they offer a sleek, streamlined appearance that sits flush against the frame. Properties with a traditional aesthetic, on the other hand, can take advantage of slide and sash windows, which are slightly more detailed. If you were to replace the windows on your conservatory, then many of our clients choose a tilt and turn styles, which offers two opening types to maximise ventilation. There are endless style properties, and our team are always more than happy to help you to shortlist options!

Once you have chosen your ideal window style, it will be vital to ensure that both the frame and glazing is efficient. Keep the different ratings mentioned previously at the forefront of your decisions, considering which are most important for your home. For instance, if your home attracts a lot of sunlight, but you want to limit this as it often overheats, then you should keep an eye out on the Visible Transmittance and SHGC ratings. It will also be crucial to complete your new windows with either double or triple glazing as, without this, your windows will not be efficient. As opposed to a single pane of glass, double or triple glazing is designed with two or three layers, each of which are separated with a layer of argon gas. This gas creates a barrier between the indoors and outdoors, preventing any heat loss and keeping your home at a comfortable temperature. For more information on the benefits of double glazing, take a look at our previous article.

Window Opening

How Can I Make My Windows More Energy Efficient?

In some cases, particularly in the lead up to Christmas and with the current climate in mind, replacing windows may not be a feasible option. If your windows are no longer efficient but you are waiting until next year to schedule a reinstallation, then it will be vital to put in place temporary fixes in the meantime to minimise heat loss over the colder months. The most effective short-term solutions include fitting draught-proofing strips. Self-adhesive foam, metal and plastic strips are all available which are placed around the window frame to seal any gaps. Foam strips are the most cost-effective option yet may not last as long as you would have hoped. It is for this reason that metal or plastic strips are recommended as they are designed with draught-excluding brushes or wipers.

Although they are nowhere near as effective as new glazing, heavy curtains are also great for creating a barrier between the colder winter conditions and the inside of your home, helping you to trap in heat. For maximum results, choose curtains that are well-lined and made from a thick, closely woven fabric. Dunelm stocks a vast range of thermal curtains in an array of colours and patterns, which are designed with an insulative coating.

Heavy Lined Curtains

Boosting The Efficiency Of Your Home One Window At A Time

Windows play a pivotal role in many aspects of your home from its ability to maintain a steady temperature, all the way through to its overall appearance. This means that while new, energy-efficient windows will come at an initial investment, scheduling a replacement will most definitely work towards your advantage and provide you with long-term benefits. If you would like more information on replacing your windows, then please do not hesitate to get in touch with our team. With many years of experience in double glazing in Buckingham and the surrounding areas, we will spend time understanding your requirements before pairing your home with the best-fitting products to maximise efficiency.