Winter Window Guide: Warm Homes and Low Energy Bills

As winter chills set in and energy costs continue to rise with the latest budget, many UK homeowners are searching for practical ways to reduce heat loss and improve their home's efficiency. However, you don’t need to look far to find places to improve, with one of the biggest culprits being your windows. 

Windows account for up to 30% of heat loss in the average home.

The good news? Most window-related heat loss can be fixed with simple DIY repairs and upgrades that cost far less than replacing your windows entirely. In our winter window guide, we'll show you how to insulate windows and how your repairs can make your home a little more cosy.

Understanding Heat Loss Through Windows

Before diving into window insulation solutions, it's helpful to understand the main ways heat escapes through your windows:

Gaps and Draughts: Worn or damaged rubber seals around the window frame allow cold air to seep in and warm air to escape. This is the most common cause of heat loss.

Poor Ventilation Balance: Without proper ventilation, like trickle vents, condensation builds up, leading to damp and mould. This can make your home feel colder and less comfortable.

Damaged Hardware: Broken or loose window handles prevent windows from closing properly, creating gaps that let heat escape.

Poor Glazing: While this requires professional replacement, maintaining the seals around your existing glazing can maximise their efficiency.

Your Winter Window Maintenance Checklist

So with this in mind, where can you begin?

1. Check and Replace Worn Rubber Seals

Perished rubber seals are the number one cause of draughts. Even small gaps can make rooms feel significantly colder and increase heating costs.

What to look for:

• Cracks, splits, or hardening in the rubber
• Visible gaps when the window is closed
• Noticeable draughts around the frame
• Condensation forming between the seal and frame

There are two main types of seals in uPVC windows: bubble gasket seals (around the window opening and glass) and wedge gasket seals (around the glass itself). Replacing these is one of the most cost-effective improvements you can make.

Learn how: How to Replace Rubber Seal on uPVC Windows

2. Install or Replace Trickle Vents

Proper ventilation is crucial in winter. Modern homes are well-insulated, which is great for retaining heat, but without adequate airflow, moisture becomes trapped. This leads to condensation, mould growth, and that damp, cold feeling.

What to look for:

• Excessive condensation on windows in the morning
• Mould forming around window frames
• Musty smells in rooms
• Missing or blocked trickle vents

Trickle vents provide controlled ventilation without creating draughts. They allow moisture to escape while maintaining your home's warmth.

Learn how: How to Fit a New Window Trickle Vent

3. Repair or Replace Broken Window Handles

A faulty window handle can prevent your window from closing and locking properly. This creates gaps that let cold air in and warm air out. A loose or broken handle can also be a security risk.

What to look for:

• Handles that won't lock fully
• Loose or wobbly handles
• Handles that have snapped or broken
• Difficulty opening or closing windows

Replacing a window handle is a quick 10-minute job that can make an immediate difference to your comfort and security.

Learn how: How to Replace a uPVC Window Handle

Additional Winter Window Insulation Tips

Use Heavy Curtains and Blinds

Switching to winter curtains and blinds can be useful for trapping in heat. You can also aim to close curtains at sunset to trap any heat from the sun inside. Thermal-lined curtains can reduce heat loss through windows significantly as they provide an extra layer of protection against the elements. You should also keep them open during sunny winter days to benefit from natural solar heating.

Check for Frame Damage

Next, you may want to inspect your window frames for cracks, rot, or warping. The bad news is if you find these issues, they may require more extensive repairs. However, the benefit to your home heating may be worth the investment.

Consider Your Glazing

If you have single-glazed windows, secondary glazing (adding a second pane inside the existing window) can dramatically improve insulation without the cost of full window replacement.

Don't Forget Your Doors

Apply the same principles to your doors. Check door seals, draught excluders, and letter box brushes. Even small gaps under doors can let significant amounts of cold air in.

How To Get Started

The best approach is to work systematically through your home:

1. Inspect all windows - Note which ones have issues with seals, handles, or ventilation
2. Order samples - Get seal samples to test before ordering full rolls
3. Prioritize repairs - Start with the rooms you use most or where draughts are most noticeable
4. Set aside a weekend - Most homes can have all windows serviced in a single weekend

Work with GB DIY Today

With all that said, we’re here to help you insulate your windows this winter. These simple, affordable DIY fixes can transform your home's comfort and efficiency, with most repairs requiring only basic tools and a few hours of your time.

At GB DIY Store, we stock everything you need for winter window maintenance:

• Bubble gasket and wedge gasket seals in various sizes
• Sample packs to help you choose the right fit
• Through-frame trickle vents in multiple colours and sizes
• uPVC window handles and accessories
• TCT drill bits for steel-reinforced frames

All our products come with clear guidance, and our team is always happy to help if you have questions.

By taking action now, you'll enjoy a warmer home, lower energy bills, and the satisfaction of knowing you've made your home more sustainable for years to come.

Have questions about your window maintenance? Contact our team at GB DIY, we're here to help you keep the warmth in this winter. For more information, visit our Seal Centre resource and find everything you need to know to keep your home warm with GB DIY.