What to look for when buying double glazing

• October 12, 2026|
• Windows|
• sandymount_admin

New double glazing can transform your home, giving you warmer rooms, quieter nights and a fresh look you will enjoy every day. Because it is a significant investment in your home, it pays to know what to look for when buying double glazing before you compare quotes. The right choice comes down to six key areas: the glass type, the energy rating, the security features, the window frames, the installation and the guarantee. Get these right and you can enjoy your new windows for decades to come.

Start with your home’s needs

Before choosing styles and colours, consider what you want your new windows to improve:

• Warmth: cold spots, heat loss or heating that struggles to keep up
• Quiet: traffic noise reaching bedrooms and living areas
• Security: older locks or ground-floor windows that feel vulnerable
• Appearance: frames that let in plenty of light, suit heritage properties or give a newer home more kerb appeal

Knowing your priorities makes it easier to compare quotes and see which features are worth paying for.

Glass options and energy ratings

For comfort and lower bills, the glass and its energy rating matter most.

Choosing the right type of glass

Double glazing is the standard choice for most homes. Its two panes of glass, separated by an insulating gap, keep heat in and help reduce outside noise.

Triple glazing adds a third pane for extra thermal insulation and better noise control. It can be the best option for homes in open, windy settings or beside busy roads. We supply double and triple glazing and can give expert advice on the right glass type for your home.

What do window energy ratings mean?

Window energy ratings run from A++ down to E and are set by the British Fenestration Rating Council. They measure the energy efficiency of the whole window, frame and glass together, so a higher rating means warmer rooms and lower running costs.

Good thermal efficiency means rooms stay warm right up to the glass, with fewer cold spots and draughts. The benefit shows in your bills too. The Energy Saving Trust estimates that upgrading single glazing to A-rated double glazing can save around £85 a year on energy bills.

That is why energy performance is built into every window we supply. Our uPVC windows are A-rated as standard, and our aluminium windows offer excellent energy ratings that exceed building regulations. Whichever you choose, you can look forward to a warmer home and lower bills.

Security features worth prioritising

Window security has improved significantly. Many older frames rely on a single latch, but modern windows are designed and tested to resist forced entry. Look for:

• Multi-point locking: secures the window to the frame at several points, leaving no single weak spot
• PAS 24 testing: the British standard that tests how well windows resist attempted break-ins
• Secured by Design: the official police security initiative, which recognises products that meet rigorous standards

Some quotes list security features as optional extras, so check what is included. At Sandymount, every window we fit includes all three as standard, giving you complete peace of mind that your home is protected.

Comparing frame materials

The frame material you choose shapes the look of your home, how long your windows last and how much care they need. We offer uPVC and aluminium windows, and each has its own strengths:

For period properties, a flush sash or sash style of uPVC window with a woodgrain finish keeps the character of your home with modern performance.

For a contemporary look, aluminium windows are a popular choice, alongside our classic casement windows. Pairing your windows with uPVC doors in the same finish creates a consistent look that adds to kerb appeal and the value of your home.

Installation quality makes the difference

Installation has as much impact on performance as the window itself. A well-made window that is poorly fitted can let in draughts, gather condensation and lose heat, undoing the energy rating you paid for. Before you commit, check that your installer:

• Is FENSA registered, which you can check on a professional directory such as FENSA’s installer search
• Uses their own fitters instead of subcontractors

With over four decades of experience, our Cirencester-based team measures and fits every window. We are also FENSA registered, so all the replacement windows we fit are certified as fully compliant with building regulations. You will receive a FENSA certificate as proof, which you will need if you sell your home.

Check what the guarantee covers

A guarantee protects your investment long after installation. A strong one covers the frames, sealed glass units and hardware for many years, and shows a company stands behind its products and workmanship.

Our Origin windows come with a 20-year guarantee, giving you long-term peace of mind. Always ask for the guarantee terms in writing before you commit.

How to weigh up costs

New windows are a big financial investment, so get a selection of quotes from local suppliers. Look beyond the headline price, as a low quote can raise the overall cost over time through a weaker energy rating, a shorter lifespan or a less comprehensive guarantee. When comparing, consider:

• Installation costs: check that fitting, removal of old windows and the guarantee are itemised
• Running costs: the highest energy ratings keep heating bills down year after year
• Property value: quality windows are a home improvement that buyers notice

Find the right windows for your home with Sandymount

Now you know what to look for, you can choose with confidence. Our specialists can recommend windows to suit your home and priorities. You will receive expert advice and a clear, no-obligation quote, with no pressure to decide on the day. For inspiration, take a look at our past projects.

Get in touch today to arrange your free consultation:

• Enquire online
• Call us on 01793 230684
• Email windowsanddoors@sandymount.co.uk
• Visit our showroom in Cirencester to see our range of windows