Tired of Draughts? Here’s How to Fix Them
That winter chill creeping through your sash windows? It’s not just uncomfortable—it’s costing you money. Homes lose up to 25% of their heat through windows and doors, but with simple draught-proofing, you can cut heat loss by 15%, making your home warmer and reducing energy bills.
The best part? You don’t need to be a professional to install draft excluders. With the right tools and a step-by-step guide, you can tackle this DIY project in an afternoon—no costly repairs or replacements needed.
Why Draught-Proofing Your Sash Windows is a Smart Move
- Lower Energy Bills – Reduce wasted heat and save on energy costs year-round.
- Eco-Friendly – Cut your carbon footprint by improving insulation.
- Preserve Your Windows – Avoid warping, rattling, and damage caused by air leaks.
- Simple DIY Solution – No need to replace your windows—just seal the gaps effectively.
Will This Guide Work for My Sash Windows?
Yes! Whether you have single-hung, double-hung, or Victorian sash windows, this guide will help you identify where heat is escaping and how to seal those draughts without compromising function.
You’ll need:
✔️ Weatherstripping or brush seals – Flexible and effective.
✔️ Draught-proofing strips – Easy to install along the meeting rails.
✔️ A putty knife & tape measure – For a perfect, snug fit.
All materials can be found at any hardware store, and we’ll show you exactly how to install them step by step.
Does This Actually Work?
Absolutely. This guide is based on 20+ years of expertise in sash window restoration across London. If you follow these steps, you’ll:
✅ Stop rattling and cold air leaks immediately.
✅ Feel the difference in warmth within hours.
✅ Avoid expensive window replacements by maintaining your original sash windows.
Ready to Get Started?
Let’s banish those draughts for good. Follow our guide, and enjoy a warmer, more energy-efficient home—without professional costs.
The Hidden Costs of Draughty Windows – and How to Fix Them
Are Your Sash Windows Costing You More Than You Think?
You might not see it, but draughty sash windows are quietly draining your wallet and reducing your home’s comfort. Homes lose up to 25% of their heat through windows and doors, forcing your heating system to work overtime—and your energy bills to skyrocket.
By installing draught-proofing, you could reduce your heating energy use by up to 30%, saving between £100-200 per year. A simple upgrade now means lower bills, a cosier home, and fewer sleepless nights listening to your windows rattle in the wind.
How Draughts Impact Your Comfort and Indoor Air Quality
Draughts aren’t just about lost heat—they affect the air you breathe. Cold air entering your home creates temperature imbalances, making some rooms unbearably chilly while others remain stuffy. This forces your heating to work inefficiently, increasing humidity and the risk of condensation, mould, and poor air circulation.
Draught-proofing seals gaps without suffocating your home, maintaining healthy airflow while keeping the warmth in.
Will Draught-Proofing Ruin My Period Windows?
Not at all. Heritage homes thrive on careful restoration, and modern draught-proofing methods preserve original features while eliminating cold spots. Brush seals and discreet weatherstripping blend seamlessly with your existing frames, maintaining the character and value of your property.
In fact, well-maintained sash windows increase property value, as buyers favour energy-efficient, historically authentic homes.
Is Draught-Proofing Worth It Compared to Other Insulation Methods?
Absolutely. Unlike double glazing or full window replacements, draught-proofing is:
✔️ Affordable – Costs a fraction of secondary glazing or full replacements.
✔️ Non-invasive – No need for major construction or altering window frames.
✔️ Instantly effective – No waiting months to feel the results.
Plus, with draft excluders alone cutting energy bills by approximately £50-75 per year, the investment pays for itself faster than most insulation methods.
A Warmer, More Efficient Home Starts Here
Imagine curling up on your sofa during winter, finally free from cold air seeping through your windows. With expert-approved draught-proofing techniques, that’s not just a dream—it’s a simple, achievable fix.
Your Essential Toolkit for Sash Window Draught-Proofing
Gather Your Materials – No Specialist Tools Required
Draught-proofing your sash windows doesn’t require advanced skills or expensive equipment. In fact, most of what you need is likely already in your home – and if not, a quick trip to the hardware store will sort you out.
Best of all, draft excluder materials cost as little as £10-15 and can last for several years, making this a budget-friendly and effective way to improve your home’s insulation.
Essential Tools for the Job
To get started, you’ll need:
- Adhesive draft excluder tape – The simplest way to seal gaps, reducing heat loss by up to 15%.
- Silicone sealant or brush strips – Ideal for sealing larger gaps while maintaining smooth sash movement.
- Scissors or a utility knife – For precise cutting of draft excluder materials.
- Screwdriver – Needed for removing beading or securing brush strips.
- Measuring tape – Ensures an accurate fit for all materials.
- Gloves – Essential for safety when handling sharp tools or strong adhesives.
Where to Buy High-Quality Draught-Proofing Materials
Most hardware stores, home improvement centres, and online retailers stock durable, high-performance draft excluders. Look for weatherproof, long-lasting materials that won’t degrade over time.
If sustainability is a priority, opt for:
✔️ Wool pile strips – A natural alternative to synthetic brush seals.
✔️ Eco-friendly silicone sealants – Low VOC formulas for minimal environmental impact.
✔️ Recyclable adhesive tapes – Ensures your project stays green.
Safety Tips for a Smooth Installation
- Always wear gloves when using utility knives or handling adhesives.
- Work in a well-lit space to ensure precision when measuring and cutting.
- If removing old beading, be cautious—vintage windows may have fragile woodwork that requires careful handling.
A Simple Fix with Big Results
With just a handful of tools and a small investment, you can dramatically improve your home’s warmth and energy efficiency. A few hours of effort now means years of lower heating bills and greater comfort.
Perfect Measurements – The Key to a Draught-Free Home
Why Precision Matters
Incorrectly measured materials are one of the top reasons for inefficient draught-proofing. A small gap left unsealed means cold air still gets in, and over-applying adhesive can hinder sash movement. Taking a few extra minutes to measure properly ensures a snug, energy-efficient fit that lasts for years.
How to Measure Your Sash Windows Accurately
To get the best results, follow these steps:
- Measure the gaps – Use a ruler or calliper to check the space between the sash and frame.
- Take multiple measurements – Sash windows aren’t always perfectly square. Measure at the top, middle, and bottom for accuracy.
- Account for movement – Leave a 1-2mm allowance to ensure smooth sliding.
- Check the parting and staff beads – These are key areas where draughts sneak through.
Identifying Draughty Spots
Not sure where the worst leaks are? Try this:
- Candle test – Hold a lit candle near the window edges. If the flame flickers, there’s a draught.
- Smoke stick – A safer alternative, smoke will drift towards any air leaks.
- Hand test – On a cold day, slowly move your hand around the frame—you’ll feel the chill where air is getting in.
Cleaning and Prepping for Maximum Adhesion
A properly cleaned window frame improves the adhesion of draft excluders by up to 20%. Here’s how to prepare your sash windows:
✔ Remove dust and dirt – Use a vacuum and damp cloth to clear debris.
✔ Degrease the surface – Wipe with isopropyl alcohol or a mild detergent.
✔ Ensure the frame is dry – Moisture weakens adhesive strips.
✔ Check for old paint build-up – Light sanding can help ensure a smooth application.
Common Mistakes to Avoid
- Skipping the cleaning step – Dust weakens adhesive strength.
- Misjudging gaps – Overcompensating with thick seals can stop the sash from closing properly.
- Leaving gaps in sealing strips – Even a tiny unsealed area allows draughts through.
With the right prep work, your home stays warmer, your energy bills drop, and your sash windows remain a beautiful, functional feature.
Your DIY Roadmap to Draught-Free Sash Windows
Step 1: Gather Your Materials
Before getting started, make sure you have:
- Draft excluder tape (self-adhesive or brush strip)
- Scissors or a utility knife for precise cutting
- Measuring tape to ensure accurate placement
- A clean cloth and isopropyl alcohol to remove dust and grease
- A firm hand (and maybe a cup of tea)
DIY installation of draft excluders typically takes under 30 minutes per window, making it a quick and effective upgrade.
Step 2: Clean and Prep the Window Frame
A properly cleaned window frame improves adhesion by up to 20%.
✔ Wipe down the frame with alcohol or mild detergent.
✔ Ensure the surface is completely dry before applying the excluder.
✔ Check for old paint or damage—light sanding helps smooth out rough areas.
Step 3: Measure and Cut Your Draft Excluder
- Measure twice, cut once – Ensure each strip is the right length before removing the backing.
- Focus on key areas – Meeting rails, staff beads, and parting beads are prime draught points.
- Leave a slight gap at the corners to prevent bunching when the window moves.
Step 4: Apply the Draft Excluder
- Peel the backing slowly and press the tape firmly as you go.
- Use even pressure to ensure full contact with the frame.
- For brush strips, align them carefully so they don’t obstruct window movement.
Correct placement can improve room temperature retention by 20%, making a noticeable difference in comfort.
Troubleshooting: Common Issues & Fixes
❌ Excluder doesn’t stick properly? Ensure the frame is dry and free of grease—press down firmly for better adhesion.
❌ Strips too thick? Opt for a thinner excluder to maintain smooth window operation.
❌ Gaps still letting in air? Double-check for missed areas, especially around the meeting rails.
Start with one window as a test, then refine your approach before tackling the rest. You don’t need to be a pro to get professional results—just follow these steps and enjoy a warmer, draught-free home!
Avoid These Costly Errors – Get It Right the First Time
Draught-proofing your sash windows is a simple DIY project, but small mistakes can cut its effectiveness by up to 50%. Avoid frustration by learning from common pitfalls—taking a few extra minutes now will save hours of rework later.
1. Skipping the Cleaning Step
One of the biggest mistakes? Applying draft excluders to a dirty or damp window frame. Skipping surface cleaning is a leading cause of adhesive failure.
✔ Wipe down the frame with isopropyl alcohol or a mild detergent.
✔ Allow it to fully dry before applying adhesive strips.
✔ Lightly sand any rough areas for better adhesion.
2. Poor Adhesion & Fixing It
If the excluder peels off within days, it’s likely due to poor contact.
- Press firmly along the entire length to ensure a strong bond.
- If the adhesive is weak, reinforce it with a thin bead of clear sealant.
- For brush strips, check alignment to prevent gapping or obstruction.
3. Over-Compressor Too Tight?
Pressing the seal too hard can prevent your window from closing smoothly.
- Test as you install—the sash should move freely without excessive resistance.
- Choose low-profile excluders for tight spaces.
4. Leaving Gaps in Key Areas
Draughts love corners and meeting rails. Even a 2mm gap can reduce efficiency by 30%.
✔ Cut strips to precise lengths, avoiding unnecessary overlaps or gaps.
✔ Seal meeting rails and bottom sash properly for full coverage.
5. Thinking Mistakes Are Permanent
Messed up? No need to panic.
- Self-adhesive strips can be removed with a hairdryer to soften the glue.
- If replacing excluders, clean off old adhesive to prevent buildup issues.
By avoiding these common errors, you’ll save money, improve efficiency, and keep your sash windows in top condition for years!
Keep Your Windows Draught-Free for Years to Come
With just a little maintenance, your draft excluders can keep your home warm and energy-efficient for years. Proper upkeep prevents heat loss, extends their lifespan, and saves up to £100 annually on heating bills.
1. Regular Cleaning Keeps Excluders Effective
Dirt and dust can reduce the effectiveness of draft excluders, weakening their seal over time.
✔ Vacuum or brush excluders monthly to remove dust.
✔ Wipe adhesive strips with a damp cloth and mild detergent (avoid harsh chemicals).
✔ Check for peeling edges or loose brush strips after cleaning.
2. Signs It’s Time to Replace Draft Excluders
Well-maintained excluders can last 5-8 years, but here’s when to swap them out:
- Loss of adhesion – If the seal starts peeling or detaching.
- Flattened or brittle material – Worn-out foam or brush strips reduce insulation.
- Persistent draughts – Even after cleaning, cold air still seeps through.
3. Seasonal Checks to Prevent Heat Loss
A quick inspection before winter ensures your home stays warm.
✔ Light a candle or incense stick near the window frame – if the smoke flickers, there’s a draught.
✔ Run a hand along the sash edges to feel for cold air leaks.
✔ Reapply or replace excluders before colder months to maximise efficiency.
4. Replacing Worn-Out Excluders in 3 Simple Steps
Swapping out old excluders is quick and cost-effective.
1️⃣ Remove old seals carefully – Use a hairdryer to loosen adhesive before peeling.
2️⃣ Clean the surface – A mix of warm water and vinegar removes sticky residue.
3️⃣ Apply new excluders – Press firmly along the sash edges, ensuring a snug fit.
By staying on top of maintenance, your draught-proofing investment will continue to pay off for years!
Should You DIY or Hire a Pro? Let’s Compare
Not sure whether to tackle draught-proofing yourself or call in an expert? We break down the pros and cons so you can make the best decision for your sash windows.
1. Cost Comparison: DIY vs. Professional Services
Factor | DIY Draught-Proofing | Professional Service |
Upfront Cost | £10-£50 per window | £250-£500 per window |
Heat Loss Reduction | 40-50% | Up to 86% |
Time Required | 30-60 minutes per window | 1-2 hours per window |
Durability | 2-5 years | 10+ years with maintenance |
Warranty | None | Often includes a guarantee |
✔ DIY saves money but requires time and precision.
✔ Professionals offer superior results but at a higher cost.
2. When Hiring an Expert is the Better Choice
While DIY works well for minor draughts, certain situations demand professional expertise:
- Heritage properties – Preserving period features requires precision.
- Major repairs needed – Rotting wood or misaligned sashes need expert attention.
- Long-term investment – A pro’s work lasts longer and boosts property value.
3. Can You Combine DIY & Professional Draught-Proofing?
Absolutely! Tackle simple fixes yourself—like adding adhesive strips—while calling in a specialist for more complex sealing techniques.
By weighing cost, durability, and effort, you can find the perfect balance between DIY and professional services.
Go Beyond Draught-Proofing – Boost Your Window Efficiency
Already draught-proofed your sash windows but looking for even better insulation? These extra measures will take your energy savings to the next level!
1. Upgrade to Secondary Glazing for Maximum Insulation
Adding secondary glazing—a discreet internal glass panel—can cut heat loss by up to 40%. It’s ideal for period properties where double glazing isn’t an option.
✔ Pros: Retains the classic look of sash windows while improving insulation and noise reduction.
✔ Cons: Higher upfront cost (£150-£400 per window), but long-term savings can reach £150-£300 per year.
2. Thermal Curtains & Blinds – Simple Yet Effective
Heavy thermal curtains or insulating blinds trap warmth inside, reducing heat loss even further.
- Choose floor-length, thick-lined curtains for best results.
- Close them at dusk to prevent heat escaping overnight.
- Combine with window films for an extra insulation layer.
3. Weatherstripping – A Quick Fix for Gaps
If you still feel a slight draught, weatherstripping around the sash frame seals any remaining gaps. Look for silicone-based strips for durability.
By layering these solutions, your sash windows will stay warm, efficient, and timeless—no major renovations needed!
The Financial Benefits of Draught-Proofing Your Windows
Draught-proofing isn’t just about comfort—it’s one of the smartest energy-saving investments you can make. With rising energy costs, even a modest upgrade can lead to significant long-term savings.
1. How Much Can You Save?
By sealing gaps in your sash windows, heat loss can be reduced by up to 30%, cutting annual heating bills by £100-£200.
Draught-Proofing Method | Initial Cost | Heat Loss Reduction | Estimated Annual Savings |
DIY Draft Excluders | £10-£50 | 15-40% | £50-£100 |
Professional Draught-Proofing | £250-£500 per window | Up to 86% | £150-£300 |
Secondary Glazing | £150-£400 per window | 40-50% | £150-£300 |
Thermal Curtains/Blinds | £40-£150 | 15-25% | £50-£150 |
With DIY solutions costing under £50, they offer an impressive return on investment—paying for themselves within months.
2. Are There Government Incentives?
In the UK, homeowners may qualify for energy efficiency grants through:
- The Energy Company Obligation (ECO4) scheme
- Local Authority grants for energy-saving home improvements
- Green Homes initiatives offering financial support
Checking with your local council can reveal funding options to offset costs.
Draught-proofing isn’t an expense—it’s a cost-saving upgrade that pays for itself while keeping your home warm and energy-efficient.
Reduce Your Carbon Footprint While Staying Warm
Draught-proofing your sash windows isn’t just a smart financial decision—it’s a major win for the environment. By sealing gaps and reducing heat loss, you lower your home’s energy consumption, cutting carbon emissions and making your home more sustainable.
1. How Does Draught-Proofing Help the Environment?
Home heating accounts for 63% of total household energy use, making insulation one of the most effective ways to reduce your carbon footprint. Proper draught-proofing can:
- Lower household carbon emissions by up to 250kg per year
- Reduce reliance on fossil fuels used for heating
- Improve overall energy efficiency, meaning less waste and a greener home
Combined with other eco-friendly upgrades like secondary glazing or thermal blinds, the impact is even greater.
2. Can Draught-Proofing Qualify for Energy Efficiency Grants?
Yes! Many UK homeowners can access government incentives for insulation, including:
- ECO4 Scheme – Helps low-income households improve energy efficiency
- Local council grants – Some areas offer funding for draught-proofing projects
- Sustainability certifications – Boost your home’s value by meeting green home standards
Checking with your local authority can reveal potential financial support to offset costs.
Draught-proofing isn’t just a home improvement—it’s a commitment to sustainability that benefits both your wallet and the planet.
Make Your Home Warmer, More Efficient, and Draught-Free
There’s never been a better time to draught-proof your sash windows. Whether you’re a hands-on DIYer or prefer professional installation, the benefits start immediately—lower energy bills, better comfort, and a greener home.
1. DIY or Professional? Your Choice, Your Savings
If you’re tackling this as a DIY project, you’ll be glad to know:
- DIY draught-proofing costs as little as £10-£50 but can save up to 15% on heating bills annually.
- With the right tools, most sash window draught-proofing projects can be completed in under an hour.
- We’ve put together a step-by-step PDF checklist to make your DIY project effortless. Download here.
If you’d rather leave it to the pros, our expert draught-proofing services ensure maximum energy efficiency with durable, high-quality materials. Get a free consultation today!
2. Get Everything You Need
To help you get started:
✅ Shop Recommended DIY Tools & Materials
📋 Download Our Free Draught-Proofing Checklist
📞 Request a Free Consultation
Act now to enjoy a warmer, more efficient home—and start saving immediately.
Frequently Asked Questions – Draught-Proofing Your Sash Windows
1. Can I draught-proof my sash windows without affecting their appearance?
Absolutely! Modern draught-proofing solutions are designed to be discreet and maintain the aesthetic charm of period sash windows.
- Brush-style excluders blend seamlessly with woodwork and remain virtually invisible.
- Magnetic secondary glazing offers near-invisible insulation while preserving the window’s character.
- Concealed perimeter sealing prevents heat loss without altering heritage aesthetics.
- Professional draught-proofing specialists use tailored methods that enhance energy efficiency without compromising authenticity.
👉 Many draught-proofing methods are nearly invisible and maintain the traditional character of sash windows.
2. How often should I replace my draught excluders?
Typically, every 5-8 years, but this varies based on material quality and weather conditions.
- Annual winter checks help identify worn seals before heating season.
- Adhesive-backed excluders degrade faster than professionally fitted ones.
- Silicone and brush seals last longer and withstand harsh conditions better.
- Humid climates may require more frequent replacement due to moisture exposure.
👉 Regular maintenance can extend the lifespan of draught excluders up to 10 years in well-maintained sash windows.
3. Do draught excluders work on all types of sash windows?
Yes, but proper fitting is crucial for effectiveness.
- Flexible draught excluders accommodate most sash window sizes.
- Custom-cut solutions ensure a perfect fit for heritage properties with unique frames.
- Listed buildings may require specialist solutions to comply with conservation guidelines.
- Different adhesives work better on wood, metal, or uPVC frames—choosing the right one is key.
👉 Over 90% of sash windows can be successfully draught-proofed with standard or custom solutions.
4. Will draught-proofing my sash windows increase my property value?
Potentially, yes! Energy-efficient upgrades are highly attractive to buyers.
- Draught-proofed period homes sell faster due to improved efficiency.
- Heritage property incentives may be available for conservation-friendly upgrades.
- Buyers prioritise homes with lower energy costs and better EPC ratings.
- Professionally draught-proofed homes often see increased market appeal.
👉 Energy-efficient homes with properly insulated sash windows are more attractive to buyers and may sell for up to 5% more.
5. Can I combine draught-proofing with secondary glazing for extra insulation?
Yes! Pairing both methods maximises energy efficiency.
- Secondary glazing reduces noise pollution while preventing heat loss.
- Combining methods can cut heat loss by over 70%.
- DIY-friendly magnetic glazing panels are removable and effective.
- Building regulations for listed properties often favour non-permanent solutions like secondary glazing.
👉 Combining secondary glazing with draught-proofing can reduce heat loss by up to 70%.
6. What’s the fastest way to check if my sash windows are draughty?
Try these quick and easy tests:
- Candle test – Hold a candle or incense stick near the window edges. If it flickers, there’s a draught.
- Feel for cold air – On a windy day, run your hand around the frame to detect leaks.
- Use an infrared thermometer – Spot temperature variations around the window frame.
- Listen for rattling or whistling sounds – These often indicate air leakage.
👉 An easy way to detect draughts is by using the ‘candle test’—watch for flickering near window edges.