Is it illegal to have single glazing in 2025?
Is it illegal to have single glazing in 2025?
If you’ve ever wondered whether single glazed windows are illegal in 2025, the short answer is simple: No — single glazing windows are not illegal in the UK. You can still live in a house with single glazed windows, and landlords can still rent properties with them.
However, there’s a big difference between “not illegal” and “a good idea.” Building regulations and the minimum energy efficiency standard have been getting stricter for years. If you want a warmer home, lower energy bills, and better energy efficiency, upgrading to double glazed windows (or even triple glazing) is one of the smartest moves you can make.
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Don't miss out on the incredible benefits of double glazing. By upgrading, you'll:
Save on Energy Bills: Reduce heat loss and lower your heating costs.
Enhance Home Comfort: Maintain a consistent indoor temperature throughout the year.
Boost Security: Strengthen your home's defenses with tougher, more secure windows.
Increase Property Value: Add value to your home with modern, efficient windows.
Take the first step towards a more comfortable and cost-efficient home. Click the button below to get your free, no-obligation quotes from top-rated local providers.
What the Law Actually Says
Under UK law, there is no outright ban on single glazing in existing homes — including listed properties or homes in conservation areas. But if you build a new house or do major work (like replacing windows or extending a property), you must follow building codes that require you to meet certain energy efficiency standards.
That usually means double glazing installed or even double or triple glazing with a good u value to meet the target energy efficiency rating.
Local councils and your local authority can enforce these standards, especially if you’re doing work that needs planning approval.
Why Single Glazing Is Becoming Obsolete
Even though single glazed windows are not illegal, they are far less energy efficient than double glazing.
A single glazed window is just one glass pane, which lets heat transfer freely. In the colder months, this means you lose warm air quickly, leading to higher energy bills and a less comfortable indoor temperature.
By contrast, double glazing uses two glass panes with a gap between them (air or inert gas) to retain heat, reduce heat loss, and keep cold air out. That means a home that feels warmer in winter, cooler in summer, and better at keeping out external noise and noise pollution from busy streets.
Energy Efficiency, EPC Ratings & Your Wallet
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Upgrading to energy efficient windows can have substantial benefits:
Lower heating costs – According to the Energy Saving Trust, replacing single glazing with A-rated double glazed windows could save £135–£250 a year, depending on your property size.tt
Improved EPC rating – A better energy performance certificate score makes your property more attractive to buyers and renters.
Long term savings – Although the initial investment can feel big, double glazing or secondary glazing pays off through energy savings and reduced heat loss over time.
Environmental sustainability – Using less energy means fewer carbon emissions, which is better for the planet.
What About Rental Properties and Tenancy Agreements?
Landlords must meet the minimum energy efficiency standard (MEES), which means most rentals must have an EPC rating of E or above. If a home still has single glazing, the landlord might need to upgrade to more energy efficient windows or add secondary glazing to stay compliant.
A tenancy agreement cannot override these legal requirements — so if you rent, you have a right to ask your landlord about upgrades if your home is too cold or draughty in the colder months.
Experience the Comfort of Double Glazing Today!!!
Feel the difference with double glazing:
Enhance Your Home's Comfort: Enjoy a more consistent indoor temperature year-round.
Reduce Noise Levels: Keep external noise at bay for a quieter home environment.
Save on Energy Bills: Benefit from improved insulation and lower heating costs.
Increase Property Value: Add value to your home with modern, efficient windows.
Click the button below to discover how double glazing can transform your home.
Double Glazing vs Triple Glazing vs Secondary Glazing
Here’s a comparison table to help you decide:
| Option | What It Is | Benefits | Best For |
|---|---|---|---|
| Double Glazing | Two glass panes with air or gas gap | Good sound insulation, lower energy bills, cost effective | Most UK homes |
| Triple Glazing | Three panes with extra insulation | Best heat conservation, lower U value, quietest | Colder climates or near busy streets |
| Secondary Glazing | Extra panel added to existing window | Good for listed buildings or older buildings | Conservation areas, listed properties |
Upgrade Your Windows Today!!!
Don't miss out on the incredible benefits of double glazing. By upgrading, you'll:
Save on Energy Bills: Reduce heat loss and lower your heating costs.
Enhance Home Comfort: Maintain a consistent indoor temperature throughout the year.
Boost Security: Strengthen your home's defenses with tougher, more secure windows.
Increase Property Value: Add value to your home with modern, efficient windows.
Take the first step towards a more comfortable and cost-efficient home. Click the button below to get your free, no-obligation quotes from top-rated local providers.
The True Cost of Installing Double Glazing
Illustration of an energy-efficient home featuring solar panels, wind turbines, and a green landscape, symbolizing sustainable living and renewable energy solutions.
The cost of install double glazing varies depending on the type of replacement windows, frame material, and the installer. According to Checkatrade, you might expect £300–£600 per window.
Although it’s a big initial investment, the long term savings, higher property value, and improved safety standards make it a smart choice.
Find the Best Double Glazing Installers in Your Area!
Ensure your windows are installed correctly by professionals:
Expert Installation: Guarantee quality with experienced installers.
Reputable Service: Connect with top-rated local professionals.
Timely Completion: Enjoy prompt and efficient installation services.
Competitive Pricing: Get the best value with affordable rates.
Click the button below to connect with reputable installers today.
The True Cost of Installing Double Glazing
The cost of install double glazing varies depending on the type of replacement windows, frame material, and the installer. According to Checkatrade, you might expect £300–£600 per window.
Although it’s a big initial investment, the long term savings, higher property value, and improved safety standards make it a smart choice.
Common Problems With Old Windows
Older single-glazed windows often come with a host of issues that homeowners feel every winter:
1. Air leaks and draughts
With only one thin pane of glass, gaps and poor sealing are common. These leaks let cold air in and warm air out, making your heating system work overtime. The result? Higher energy bills and rooms that never quite feel cosy.
2. Condensation
Because single glazing offers very little thermal insulation, the inside pane quickly gets cold. This often leads to condensation build-up, damp patches on walls, and even mould growth. Beyond being uncomfortable, this can also create long-term health risks and damage to your property.
3. Poor sound insulation
A single pane of glass does little to block outside noise. Whether it’s traffic, noisy neighbours, or planes overhead, single glazing can make your home feel far less peaceful compared to modern double or triple glazing.
4. Failing to meet modern energy standards
In 2025, homeowners are more conscious than ever about energy efficiency. While single glazing isn’t outright “illegal,” it usually falls well below the standards required for a good Energy Performance Certificate (EPC) rating. This can affect your comfort, increase running costs, and even reduce the resale value of your home.
Replacing or draught-proofing old windows can make a big difference. Not only does it improve your energy efficiency rating, but it also boosts comfort, reduces noise, and makes your property more attractive to future buyers.
New Sections for More Depth
1. The Science Behind Heat Transfer and Glazing
When you have single glazed windows, heat moves freely by heat transfer, causing warm air to escape quickly. Double glazing traps a layer of gas between two panes, which slows this transfer and helps you retain heat. The result: a more comfortable indoor temperature and lower bills.
2. The Role of Local Authority and Building Codes
Your local authority enforces building regulations and energy standards. If you live in a listed building or conservation area, you might need special permission to change your glazed windows — but you can often use secondary glazing to meet the rules while preserving the aesthetic appeal of older buildings.
3. Noise Reduction and Human Health
Noise pollution from traffic, neighbours, or busy streets can affect human habitation and sleep quality. Double or triple glazing provides better noise reduction, helping create a quieter, healthier home.
4. The Financial Benefits Over Time
Yes, double glazing compulsory upgrades cost money — but the long term savings are worth it. Energy prices are rising, and higher energy bills can add hundreds of pounds per year. Energy efficient windows pay for themselves by cutting heat loss and reducing your reliance on heating.
5. Choosing the Right Windows for Your Home
When replacing windows, consider frame material, glazing type, and u value. Timber offers natural aesthetic appeal, while uPVC is more cost effective. Aluminium works well in modern builds. Pick the right windows to balance looks, budget, and performance.
6. How to Avoid Cowboy Installers
Poorly double glazing installed units can lead to air leaks, condensation, and wasted money. Always choose FENSA-registered installers to ensure compliance with building codes and get a proper guarantee.
Frequently Asked Questions
No — single glazed windows are not illegal. But if you are installing new windows, doing major renovations, or building from scratch, you must meet energy efficiency standards that usually require double glazing installed. For rentals, you must also meet the minimum energy efficiency standard set by the government.
You can save hundreds every year. Upgrading from single glazed windows to energy efficient windows reduces heat loss, improves energy efficiency rating, and lowers higher energy costs.
Not always — in listed buildings, planning permission may restrict replacement windows. But secondary out glazing or slimline double glazing options can help meet building regulations while preserving aesthetic appeal.
Double glazed windows greatly improve sound insulation compared to single glazed ones, making them perfect for homes near busy streets or in noisy neighborhoods.
With double glazing, you can save between £75 and £235 per year on energy bills, depending on the size of your home and the type of windows you’re replacing. The improved insulation reduces heat loss, meaning you’ll spend less on heating your home. Over time, these savings can add up, making double glazing a cost-effective investment.
Upgrading single glaze windows in an older home is generally worthwhile. While it may seem like a significant investment, the benefits include improved energy efficiency, reduced heating and cooling costs, and increased home comfort. For heritage properties, specialized double glazing options can preserve the aesthetic while enhancing performance. Additionally, the upgrade can boost your home’s market value, making it a wise financial decision.
While single glaze windows are initially more affordable to purchase and install, they can become more expensive over time due to higher energy costs. The lack of insulation in single glazing means your home will lose heat more quickly, leading to increased heating bills in the winter. In contrast, double glazing, although more costly upfront, offers better long-term savings through reduced energy consumption.
Article by
Emily Roberts
Home Improvement Specialist at HotSavings
Emily has over 8 years of experience helping UK homeowners make smart, energy-efficient upgrades—from glazing and conservatories to solar panels and modern boilers.
She specialises in guiding families through government-backed schemes, cost-saving installations, and practical solutions that boost home comfort and value.
