How Windows Affect Energy Bills
Did you know you can lose up to 40% of your heat through your windows and doors?
Although the walls, roof and floor allow more heat loss through bigger surface areas, gaps in windows, broken seals and other inefficiencies could significantly increase your energy bills and carbon footprint.
It’s no surprise that with the rising cost of living and a shift towards eco-conscious living, energy-efficient windows are a hot topic.
Experts agree that most homeowners could reduce their heating bills by around 20% a year.
The savings will depend on several factors, including other energy-efficiency levels in the home and the materials used in the windows. However, upgrading the windows in a single-glazed semi-detached house to double-glazed A-rated windows could save you up to £155 a year. Installing A ++ rated double-glazed windows in the same home could save you approximately £170 a year.
It’s important to note that you will save up to 375kg or 410kg of carbon dioxide, respectively.
Energy bills are set to increase again in April, so this could be your ideal opportunity to enhance your home’s energy efficiency by repairing or replacing your windows.
We have previously provided background on how energy-efficient windows can save you money and help lower your carbon footprint. In this blog, we delve deeper into what makes a window energy-efficient and how to choose the best ones for you.
What Makes a Window Energy-Efficient?
Windows are rated for their energy efficiency, among other factors, and carry an A-rating and a U-value, which you can check.
The u-value measures how easily heat passes through the material, while the A rating is an overall energy efficiency score.
This score is decided by rigorous testing of the window’s components, as follows:
- Glazing type
- Frame Material
- Seals and Weatherproofing
Glazing Type:
Your choice of glazing significantly affects the energy efficiency of your window. Manchester Window Factory offers several types of glass with innovative technology to maximise insulation and other benefits.
Low-E Glass
Energy-efficient windows are typically double or triple-glazed or can incorporate specially designed energy-efficient glass such as Planitherm. This Low-E glass has a special microscopic coating that blocks the sun’s harmful UV rays while retaining more heat in your home. Low-E glass helps to regulate a room’s temperature and reduce energy bills while allowing plenty of natural light to flow.
Single Glazing
Single glazing offers inferior energy efficiency. The single pane of glass offers very little insulation, with an average u-value of 5.2W/m²k (watts per square metre kelvin). The lower the U-value, the better.
Single glazing is no longer considered adequate for UK homes and is being phased out by the UK Government. As of April 2022, single-glazed windows do not meet building regulations, with all new builds requiring double-glazing as standard. Although it is not yet compulsory for homeowners to upgrade to double glazing, it could become mandatory soon as part of the Government’s net zero plans.
Double v Triple Glazing
Double-pane windows have an average U-value of roughly 1.2/1.4W/m²k, compared to
triple-pane windows with a U-value of around 0.9W/m²k. Some experts estimate triple-glazed windows are as much as 40 per cent more thermally efficient than standard A-rated double-glazed windows.
Installing double or triple glazing also helps reduce noise pollution, can add curb appeal, and
potentially increase your property value.
Frame Material:
Energy-efficient windows could be sliding sash or casement windows and made of timber, aluminium or uPVC.
Timber
Timber is a natural insulator. Due to wood’s low thermal conductivity (heat loss) level, a solid timber frame is highly energy efficient.
UPVC
In contrast, UPVC has been specifically designed with energy efficiency and insulation in mind. UPVC windows comprise multiple chambers for maximum heat retention.
Aluminium
Without interference, aluminium is the least energy-efficient of the three main window frame materials. As a metal, it is highly thermally conductive, enabling heat to escape. However, modern aluminium windows have fixed this issue by adding thermal breaks to stop heat from transmitting through the metal frame.
Seals and Weatherproofing:
All the seals and weather stripping must be air and water-tight to prevent draughts and leaks. Windows seals are typically made of high-grade silicone, rubber, or UPVC to create an airtight barrier between the glass and the frame.
Window seals that are working well:
- Prevent drafts
- Prevent water leaks
- Reduce condensation
- Reduce noise pollution
- Reduce energy bills
Worn seals could let in drafts and water, creating dampness, mould and mildew, which can harm your physical and mental health.
Poorly installed windows could also have gaps between the seal and the frame or glazing.
Comparing the Best Windows for Energy Efficiency
| Window Type | Energy Efficiency Rating | Weatherproofing | Best For |
|---|---|---|---|
| Stormproof Casement Windows | ⭐⭐⭐⭐ | ⭐⭐⭐⭐⭐ | Areas with harsh weather, modern homes |
| Flush Casement Windows | ⭐⭐⭐ | ⭐⭐⭐ | Traditional homes, heritage areas |
| Sash Windows | ⭐⭐ | ⭐ | Period properties, conservation homes |
| Triple-Glazed Windows | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐⭐ | Maximum insulation, eco-friendly homes |
| Secondary Glazing Windows | ⭐⭐⭐ | ⭐⭐⭐ | Listed buildings where full replacement isn’t possible |
Stormproof
Stormproof casement windows are ideal for modern UK homeowners who want to increase their home’s protection from bad weather. The lip pushes against the window seals to stop heat loss and water leaks. Fantastic for insulation, they are also secure, and they are good for blocking ambient sounds.
The only real drawback is that the lipped design may not suit all properties.
Triple Glazed
As the name suggests, triple-glazing comprises three panes of glass and inert gas filling the spaces in between. It can offer a higher level of insulation than double glazing, although the improvement may not be worth the price difference to cost-conscious homeowners.
Secondary Glazing
If you are on a tight budget or are looking for a short-term solution, consider secondary glazing.
A second pane of glass is fitted to your existing windows, minus the inert gas between the panes. It can improve energy efficiency and reduce bills and emissions, but it is not as effective as full double glazing.
If your home cannot accommodate double or triple-glazing, eg because it is a listed building, secondary glazing could offer a solution.
Why Stormproof Casement Windows Are a Smart Choice
Stormproof casement windows are a great all-rounder window. Due to their lipped design, they offer a high level of protection against inclement weather, including wind, rain, and snow.
Other benefits include:
- They are compatible with double or triple glazing for maximum insulation.
- They offer acoustic protection from ambient noise
- They are available in uPVC, timber, and aluminium, balancing efficiency.
- They are secure, with the lip acting as an extra barrier.
- They can be customised with handles and locks.
Other Ways to Improve Window Energy Efficiency
There are some other ways to improve the energy efficiency of your windows and home, depending on your budget and requirements, including the following:
- Upgrade to double or triple glazing if not already installed.
- Improve loft/roof/wall and floor insulation for a knock-on effect
- Use thermal blinds or curtains to retain heat.
- Check and replace worn-out window seals and frames.
- Try secondary glazing or thermal window film if money is tight or you are in a rented property.
Conclusion: Which Windows Should You Choose?
It’s hard to go wrong when choosing energy-efficient windows, so the final decision is likely to come down to personal taste, requirements, and budget.
Consider the glazing, frame material, and energy rating and balance the initial price and the insulation cost with the money you could save on your energy bills.
Stormproof casement windows with triple-glazing offer excellent insulation and protection from the UK’s often cold, wet and windy climate.
When it comes to making the right choice for your home, we recommend doing your research. Gather at least three quotes to compare, and always check unbiased reviews on reputable sites such as TrustATrader and CERTASS. Getting word-of-mouth recommendations from family, friends, and neighbours is also a good idea.
We work with the best manufacturers to bring you the highest quality products and provide professional installation courtesy of our in-house team.
Many of our designs are easy to clean and maintain, with customizable features.
FAQs
Triple glazing is slightly better for insulation than a stormproof-style window. Thankfully, at Manchester Window Factory, you don’t have to choose.
All our windows, including stormproof casement windows, can be double-glazed or triple-glazed or use Planitherm glass. So, you get the best of both worlds – optimal weather resistance and excellent insulation in one window.
While timber and UPVC are more energy-efficient than aluminium, the thermal breaks in modern aluminium windows have closed the gap between the three materials. It is largely down to personal preference.
Installing energy-efficient windows in your home can offer many benefits, including:
- Retaining more of the heat currently lost through your windows
- Reducing your energy bills
- Keeping your home warmer for longer
- Improving overall comfort and quality of living
- Better temperature control and air quality
- Protection against draughts
- Reduced noise pollution
- Add value to your home
- Increase curb appeal
- Reduce maintenance
- High level of security
- Reduce condensation inside the home
- Futureproof your home
Most modern energy-efficient windows require little maintenance and are built to last. Manchester Window Factory windows come with a 10-year insurance-backed guarantee for your peace of mind.
However, when properly installed and cared for, energy-efficient windows can last decades.
In most cases, a quick clean with warm soapy water and a soft cloth when they get dirty will suffice.
If you notice the following signs, your windows are losing energy:
- Draughts
- Cold spots
- Dampness
- Mould or mildew
- Water leaks or water pooling inside the frame
- Condensation/fogging between panes
- Struggling to maintain the room temperature
- Increasing energy bills
- Cracks, rotting or warping in the frame
- Peeling paint
- Gaps in the sealant
Additionally, if you have single-glazing, your windows are not suitable for current Government guidelines.
You can check for water leaks and other signs of energy loss yourself or get a professional assessment done if you are concerned or want to confirm inefficiencies.
How to Get in Touch
If you want to find out more about creating customised windows, doors, and conservatories, please don’t hesitate to get in touch. You can call us on 0161 976 4739, use our contact form or chat with us via the chat button at the bottom right of this website. If you live locally, you can also visit our Altrincham showroom, and check our contacts page for up-to-date opening hours.
We look forward to hearing from you!
