Last Updated on March 25, 2025

Double Glazing vs Single Glazing: Which Is Better?

When choosing new windows for your home or rental property, one of the biggest decisions you’ll face is double glazing vs single glazing. With the UK’s rising energy costs and unpredictable weather, selecting the right type of glazing can make a significant difference in your property’s insulation, security, and overall energy efficiency.

In this guide, we’ll compare the two window types in-depth, covering insulation, security, ventilation, light transmission, maintenance, and costs. By the end, you’ll have a clear understanding of which option suits your needs best.

What Is Single Glazing?

Single glazing consists of just one pane of glass in the window frame. It was the standard for UK homes for many years before double glazing became more widely available.

Key Features of Single Glazing

Pros and Cons Of Single Glazing

What is Double Glazing?

Double glazing consists of two panes of glass separated by an air or gas-filled gap, usually 16mm wide. The gap is filled with argon or krypton gas, improving insulation and reducing heat loss.

Key Features of Double Glazing

Pros and Cons Of Double Glazing

Which Window Styles Can Be Single or Double Glazed?

Both single and double glazing can be installed in various window types, but some limitations exist depending on the property type and regulations. For example, listed buildings or homes in conservation areas may require single glazing or secondary glazing solutions.

If you’re in a conservation area or own a listed property, check with your local planning authority before replacing single glazing with double glazing.

If you’re considering upgrading your home with new windows, visit our window replacement quote page to get competitive prices on new windows. Whether you’re interested in double or single glazing, we can help you make an informed choice and find the best deal for your property. 

Energy Efficiency & Insulation

One of the most significant differences between double glazing vs single glazing is energy efficiency.

Heat Retention & U-Values

U-values measure how well a window retains heat. A lower U-value means better insulation.

Why Insulation Matters in the UK

The UK’s climate can be cold and wet, especially in winter. Poorly insulated windows mean more heat escapes, making homes harder to heat and more expensive to run.

• In older properties with single glazing, heat loss through windows can account for up to 25% of total heat loss.
• Double glazing dramatically reduces heat loss, keeping homes warmer in winter and cooler in summer.

Winner: Double Glazing – It significantly improves heat retention, making it the best choice for energy efficiency.

Costs & Installation

The cost of double glazing is a major deciding factor for homeowners and landlords considering an upgrade.

Price Comparison of Single vs Double Glazing

Factors Affecting the Cost:

1. Frame Material – uPVC is the most affordable, while timber is more expensive.
   
2. Glass Type – Low-E glass, laminated glass, or tinted glass can increase costs.
   
3. Labour Costs – Prices vary depending on the installer and location.
   
4. Window Size & Style – Larger windows and complex designs cost more.

Check out our guide on new window costs for a clearer idea of what you can expect to pay.

Long-Term Savings

While single glazing is cheaper upfront, double glazing pays for itself over time through lower energy bills. The Energy Saving Trust estimates that homeowners in the UK can save up to £235 per year on energy bills with double glazing.

Winner: Single Glazing for Initial Cost, but Double Glazing for Long-Term Value. Take a look at our guide on double glazing costs for a detailed price breakdown.

Single Glazing vs Double Glazing: Which One Should You Choose?

Choosing between single glazing and double glazing ultimately depends on several factors, including your budget, the type of property you own, and your specific needs for energy efficiency, security, and noise reduction.

When to Choose Single Glazing

Single glazing is often the more affordable option, making it suitable for homeowners on a budget or those looking to replace windows in period properties or conservation areas where planning restrictions may limit the use of double glazing. 

It also offers a classic aesthetic that some may prefer in older homes. However, single glazing provides minimal insulation, which can lead to higher energy bills over time and greater heat loss, especially in colder climates like the UK.

When to Choose Double Glazing

On the other hand, double glazing is the more energy-efficient choice. If you’re looking to reduce energy consumption and improve the insulation of your home, double glazing is the better option. 

It’s particularly beneficial for those living in areas with extreme weather conditions, as it helps keep the warmth in during winter and the coolness in during summer. Double glazing also provides superior noise reduction, making it ideal for homes located in busy areas or near traffic.

Additionally, while the initial cost is higher, the long-term energy savings can make double glazing a smart investment.

Making Your Decision

When deciding between single and double glazing, consider your long-term goals. If energy efficiency, noise reduction, and improved comfort are your primary concerns, double glazing is the clear winner. 

However, if your main goal is to maintain the historical integrity of your property or if you’re working with a limited budget, single glazing may still be the right choice.

If you’re still unsure about which option suits your property best, there are alternatives to double glazing, such as secondary glazing, which can offer many of the benefits of double glazing without replacing your existing windows. 

Read our detailed guide comparing secondary and double glazing to gain a clearer understanding of both options.

Comparing Double Glazing to Other Options

If you’re still weighing up your options and want to dive deeper into the world of glazing, there are several other factors and alternatives to consider when upgrading your windows. Each type of glazing comes with its own set of benefits, and understanding these can help you make the best decision for your home.

These additional glazing options can provide even greater benefits depending on your unique requirements. Exploring each can help you decide the perfect solution for your home.

Considering Replacing Your Old Windows?

Upgrading your windows can improve energy efficiency, enhance home security, and reduce outside noise. Whether you’re dealing with drafts, rising energy bills, or outdated designs, investing in new windows can make a big difference.

Not sure where to start? Our team can help you find the best options for your home and budget. Get a free window replacement quote today and take the first step toward a warmer, more comfortable home.