Windows and doors

Windows and doors play an important role in keeping your home warm in winter and comfortable in summer. Older or poorly performing windows can allow heat to escape, while gaps around doors and frames can create draughts and cold spots.

Upgrading to modern, energy-efficient windows and doors can help improve comfort throughout the year, reduce heat loss, and lower energy bills.

However, replacing windows and doors is not always the most cost-effective first step. For many homes, improving insulation and carrying out draught-proofing measures can provide significant benefits at a lower cost.

Double or triple glazing?

Replacing windows and doors can be a significant investment, so you may be considering whether double or triple glazing is the best option.

Double glazing is the most common choice in the UK and can significantly improve energy efficiency, comfort, and noise reduction when compared with older single-glazed windows.

Triple glazing can provide further improvements in thermal performance and noise reduction. However, it is more expensive and may not always deliver sufficient additional savings to justify the extra cost. The most suitable option will depend on your property, budget, and priorities.

Window repairs

Modern double-glazed windows typically last between 20 and 35 years, although their lifespan depends on factors such as product quality, installation, exposure to weather, and ongoing maintenance. Timber windows may last significantly longer if they are properly maintained and repaired over time. 

Before replacing windows or doors, it may be worth checking whether draughts can be addressed through repairs or draught-proofing measures. In many cases, replacing seals, hinges, handles, locks, or individual glazing units can restore performance and extend the life of existing windows and doors.

A double-glazed window is often described as "blown" when the seal between the panes of glass fails. This can allow moisture to enter the gap between the panes, causing condensation, misting, or a cloudy appearance that cannot be wiped away from either side of the glass.

A blown window does not always mean the entire window needs to be replaced. In many cases, it is possible to replace just the sealed glass unit while keeping the existing frame, which can be a more affordable and environmentally friendly option.

If your windows or doors are becoming difficult to open or close, are draughty, or show signs of deterioration, it may be worth seeking advice from a qualified installer. 

Listed buildings and conservation areas

If your property is listed or located within a conservation area, there may be additional considerations. Replacing windows and doors may require Listed Building Consent or planning permission, particularly where the work could affect the building's character or appearance.

The good news is that there are often ways to improve comfort and reduce energy use while respecting the historic features of a property. Depending on the building, suitable measures may include:

• Secondary glazing, which adds a discreet internal pane behind existing windows while retaining the original frames
• Installing high-performing slim-profile double glazing
• Draught-proofing around windows and doors

If you own a listed property or live in a conservation area, your local planning authority may be able to advise on whether permissions are required. If you’re unsure who your Local Planning Authority is, you can find this information through the Planning Portal.

Choosing a reputable installer

When replacing windows and doors, it is important to use a competent installer.

One way to do this is to choose a company registered with FENSA. FENSA-approved installers can self-certify that replacement windows and doors meet the relevant Building Regulation requirements. 

After installation, you should receive documentation confirming the work complies with Building Regulations. This can be important if you decide to sell your home in the future.