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Window draught excluders explained

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Draught excluders for windows play a crucial role in blocking unwanted cold air and enhancing your home’s thermal efficiency. These simple, cost-effective devices ensure that windows do not become sources of energy loss, keeping interiors warm and comfortable.

What is a window draught excluder?

A window draught excluder is designed to prevent cold air from entering a room through gaps in or around windows. This preventative measure is key to enhancing energy efficiency, maintaining warmth and reducing heating costs.

Draught excluders come in various forms, including self-adhesive rubber seals, foam strips and brush-based solutions. They are made from materials designed to seal off air leaks effectively. These materials are chosen for their durability, flexibility and ability to withstand temperature changes and humidity, ensuring a long-lasting seal.

One popular type is self-adhesive draught excluder tape, which is easy to apply along the window frame. It’s made from foam or rubber and quickly and effectively seals gaps and stops draughts. Its ease of installation and versatility make it the preferred choice for many homeowners looking to improve their home’s thermal efficiency.

What are the benefits of window draught excluders?

Draught excluders prevent unwanted airflow through window gaps, contributing to a more sustainable household and offering financial benefits – the Energy Saving Trust suggests annual savings of around £45 (£50 in NI) are possible. 

Here are the key advantages of installing window draught excluders:

  • Increased energy efficiency: by sealing gaps around windows, draught excluders minimise heat loss, reducing the amount of energy required to maintain comfortable indoor temperatures
  • Reduced carbon footprint: improved energy efficiency reduces energy consumption, lowering the carbon emissions associated with heating your home
  • Decreased energy bills: the reduction in heat loss decreases heating costs, as your heating system does not have to work as hard to keep your home warm
  • Enhanced comfort: draught excluders help maintain a consistent indoor temperature by eliminating cold draughts, making your living space more comfortable
  • Reduced noise pollution: by sealing gaps around windows, draught excluders can block out external noise, contributing to a more peaceful home environment
  • Improved indoor air quality: while draught excluders prevent unwanted cold air from entering, they can also be part of a controlled ventilation system that allows for air exchange when necessary. They help manage moisture levels and reduce the risk of condensation and dampness, which can lead to mould growth. However, it’s vital to ensure adequate ventilation is maintained to avoid indoor air quality issues

How do I fit a draught excluder for windows?

Fitting a draught excluder is a straightforward DIY task that can significantly reduce draughts, improve comfort and lower heating costs.

Materials and tools needed

  • Draught excluder strip 
  • Measuring tape
  • Scissors or utility knife
  • Cleaning supplies (cloth and mild detergent)
  • Drill and screws, if necessary

Step 1: Choose the right draught excluder

  • Types: select a suitable excluder for your window type and material. Common options include self-adhesive foam strips, metal or plastic strips with brushes or wipers and silicone sealants. Foam strips do not work well for sliding sash windows; brush strips are a better option. A silicone sealant suits non-opening windows best
  • Size: measure the gaps to ensure you have enough material. The excluder should be slightly larger than the gap to ensure a tight fit

Step 2: Prepare the window

  • Clean: to ensure the adhesive sticks well, clean the frame thoroughly where the draught excluder will be applied. Use a damp cloth and mild detergent to remove dirt, grease or moisture. Allow it to dry completely

Step 3: Measure and cut

  • Measure: use a tape measure to determine the length of the excluder you need. Measure the width and height of the window frame and, for accuracy, measure the top, bottom and each side of the window frame, as there may be slight variations
  • Cut: using scissors or a sharp knife, cut the draught excluder to the required lengths. It’s better to cut lengths that are a little long rather than too short; you can always trim the excess later
  • Dry fit: Before removing any backing, position the draught excluder against the window frame to check the fit and length
Here, self-adhesive tape is being applied carefully to clean and dry windows. (Adobe)

Step 4: Apply the draught excluder

  • Peel and stick (for self-adhesive types): carefully peel back the protective strip to reveal the adhesive and press the draught excluder firmly into place along the window frame
  • Start at one corner of the window frame: press the strip firmly in place, peeling off the backing off as you go. For corners, either cut the strip to fit or fold it to ensure complete coverage without bunching up. Continue until all sides of the window frame are covered. Make sure the ends meet snugly to avoid gaps
  • Fix with screws (for non-adhesive types): if your draught excluder needs to be screwed in place, mark the screw holes, drill pilot holes if necessary and screw the excluder securely onto the window frame

Step 5: Test and adjust

  • Check: close the window to test the seal. You should not be able to feel a draught coming through
  • Adjust: if you find gaps or the window is difficult to close, adjust the strips as needed. You may need to reposition them or add additional layers in places where the gap is larger

Tips for success

  • For windows that open, apply the draught excluder onto the outside of the window frame, where the opening casement window will press against it when it’s closed, thereby ensuring a tight seal 
  • Warm the adhesive strip with a hair dryer before application in cold weather. This can help it stick
  • Regularly check draught excluders for wear and tear, replacing them as necessary to maintain their effectiveness

Can I install a window draught excluder myself?

Installing a draught excluder requires basic DIY skills. The process involves measuring the gaps, cutting the draught excluder strip to size and attaching it to the window frame, as detailed in the guide above. It’s an affordable and straightforward way to improve your home’s energy efficiency.

However, if you’re uncomfortable undertaking this task or have windows that are large, difficult to access or require more than just draught-proofing – such as repair or replacement – you may consider hiring a professional. Many double-glazing companies offer draught-proofing services in their repair and installation packages. These companies have the expertise to identify obvious draughts and less apparent heat loss areas, ensuring a thorough solution. Moreover, they can deal with complications that may arise during installation, such as windows that don’t open or close correctly after the excluder is applied.

When choosing a professional service, get multiple quotes to compare prices and services offered. You should also consider asking for recommendations from friends or family members who have had similar work done. Ensure that the company you choose is insured and offers a warranty on their work, providing added peace of mind and protection for your investment. 

Whether you do it yourself or hire a professional, addressing window draughts is a step towards a more comfortable, energy-efficient home.

Katharine Allison

Energy Saving Writer

As Independent Advisor’s energy saving expert, Katharine, a keen advocate for sustainability, is an authority on solar panels, double glazing, and cutting-edge renewable energy technologies. Her dedication merges with a commitment to enlighten and steer readers toward embracing eco-friendly solutions and the latest trends in sustainability.

With over 10 years of experience, she has worked with some of the UK’s leading companies and publications, including the Federation of Master Builders, Architectural Digest, and Denon Construction. 

Katharine is particularly passionate about consumer causes and animal welfare and has art, philosophy, and psychology degrees. She lives with her sled dogs in East Sussex.