Draught proofing: Let’s start from the beginning

Draught proofing is one of the most simple, effective and affordable ways to start upgrading your home for comfort, energy efficiency and lower fuel bills.

For many of us living in older or less energy-efficient properties, plugging unwanted gaps can dramatically reduce cold draughts, making your home feel noticeably cosier and helping your heating system by reducing unnecessary load. It’s a straightforward first step that can deliver immediate comfort benefits, a cut in heat loss, and provides a logical starting point to preparing your home for deeper retrofit improvements down the line.

In our homes, we like to be able to control our ventilation; we open windows when it becomes too hot, and close them when it’s cooler - this is ‘intended’ ventilation.

Draughts, however, are caused by unwanted cold air sneaking into your home through small gaps around windows, doors, floorboards, and even through keyholes and letterboxes - this is ‘unintended’ ventilation. These draughts make your home feel chilly, especially in winter, and might be responsible for around 15% of heat loss in a typical home.

That lost heat also loses money out of your pocket - the Energy Saving Trust claims up to £65 per year - and releases extra carbon into the atmosphere. To make matters worse, draughts can compound the feeling of coldness and discomfort in your home. Even if your thermostat reads a comfortable temperature, the sudden influx of cold air, or parts of the room that are particularly susceptible to draughts, will make you feel much colder than you actually are. You’re likely to keep cranking up the thermostat to compensate, or begin to dread spending time in certain parts of your home.

But draughts don’t just make you colder, they can also increase the risk of damp and mould - particularly if your property already struggles with ventilation. A draughty, damp and mouldy home can have significant impacts on your health in the long term.

We speak to lots of clients every day about their feelings towards their homes and hear first hand how draughts impact their comfort at home. 80-90% of our clients report issues with draughts in their homes, which just goes to show how common and widespread the issue is.

Draught proofing starts with spotting the problem. You’re looking for gaps in your home’s ‘thermal envelope’ — the barrier between your warm living spaces and the cold areas - outside or unheated spaces within the property.

Here’s how to find them:

• Look for visible gaps where light or outside air might get in, paying attention to gaps around doors, windows, or loft hatches.

• Feel with your hand or cheek for cool air movement, especially on a windy day.

• Listen for whistling or rustling noises, which is a sign that air is getting in where it shouldn’t.

For a more in-depth investigation, consider borrowing a heat camera from a local environmental group or council to help you spot hard-to-locate gaps. Our sister cooperative - Carbon Coop - offer heat cameras for their members alongside peer advice in their forums.

You could also try to procure a ‘smoke pencil’, which provides a simple visual guide to where unwanted air movement is occurring. You might even want to arrange an air pressure test (or blower door test) for a much more accurate evaluation of air leakage in your home - particularly if you think you’ve already covered the basics.

Once you’ve found the gaps, the next step is sealing them. From foam strips to door brushes and chimney balloons, there are lots of DIY-friendly and cost-effective solutions to plug the gaps.

These options allow homeowners with DIY skills to make little changes quickly, however, it’s important to note that they all require close attention to detail, thoroughness and persistence to get it right! You need to seal gaps effectively, and it might take a few attempts to achieve the right standard. Remember that while some people love fiddling about, you might not have the time, energy or ability to do so - hiring a local handyman to help is a perfectly acceptable option!

Consider developing a checklist to help you plan your investigations and to keep track of your findings. Areas we would typically recommend starting with might include:

If you use gas fires or wood burners, it’s crucial not to draught proof those rooms unless you're sure there’s still enough ventilation. Blocking airflow here can cause dangerous fumes to build up. You can still block chimneys when fires aren’t in use, just be extremely careful communicating with other members of the household about what you are doing and when to remove the block!

Sealing up draughts doesn’t mean sealing up your home entirely - this is the difference between ‘unintended’ and ‘intended’ ventilation. It’s important to keep fresh air coming in to reduce moisture and keep your indoor air healthy. This ventilation is essential for avoiding issues like damp and mould.

Ventilate your home by:

• Opening windows (even a crack makes a difference)

• Using trickle vents on windows or air bricks in walls to introduce fresh air into your home and extractor fans in kitchens and bathrooms to remove stale, moist air. Make sure you leave the extractor fan on for up to 20 minutes after you shower or bathe to keep the room ventilated.

• Considering more advanced systems such as dMEV (decentralised Mechanical Extract Ventilation), cMEV (centralised Mechanical Extract Ventilation) or MVHR (Mechanical Ventilation with Heat Recovery). These systems provide a continuous airflow through your home.

  • dMEV is a close relative of the ‘standard’ single-room extractor fan and works by running constantly and automatically ramping up when humidity is detected, rapidly extracting stale and moist air from your home and ensuring good air quality.

  • cMEV works on the same principle as above, but has one larger central fan that is connected to the wet rooms by a system of ducts.

  • MVHR goes one step further and draws in air from outside while recovering heat from the outgoing air to help with energy efficiency.

Particularly for more advanced approaches to ventilation such as cMEV or MVHR, we would recommend talking to us about a home retrofit plan survey, where we may be able to assess your suitability for these systems. Some earlier repair and maintenance work might be important to complete before progressing.

Moisture builds up in homes all the time — from cooking, showering, even breathing. If that moist air can’t escape, it condenses on cold surfaces, leading to mould and damp.

You can keep an eye on moisture levels using a budget hygrometer, which measures Relative Humidity (RH). Try to keep RH between 40–60% for a healthy home.

• Small patches of mould near the shower or sink? Clean them away.

• Spread-out patches on walls or ceilings? This may be condensation damp , so you’ll need to ventilate these rooms frequently..

• Large, dark, and wet areas? These could be signs of leaks or structural issues. Get them checked by a specialist quickly to determine next steps.

Though moisture and damp can be remedied by simple ventilation, it’s crucial to bring in a professional to identify whether there are additional contributing factors - you don’t want to make things worse! If you feel your mould and damp goes beyond small patches, we’d recommend speaking to a damp specialist.

Draught proofing is a simple but powerful way to start retrofitting your home. It's low-cost, easy to DIY, and can bring instant benefits to your comfort, your wallet, and your health. Once your home is better sealed, you can look ahead to bigger steps like insulation, heating upgrades, or renewable energy systems - but it all begins here.

For next steps in your journey, or if you want to know how to make your home warmer and healthier, why not start with a home retrofit survey? Our home retrofit planner survey can help assess your home and our skilled professional surveyors will be able to advise you on what’s possible to achieve from your home.

We support homeowners interested in improving their home energy efficiency in Greater Manchester and beyond.