Identifying Hidden Contributors to Heat Loss in Your Home

Keeping your home warm during the colder months can be a challenge, especially when heat sneaks out through hidden cracks, gaps, and poorly insulated areas. This not only leads to higher heating bills, but also uncomfortable drafts and cold spots. The good news is that many of these problematic areas can be identified and addressed with some diligent investigation and air sealing. 

Whether you’re aiming to improve your property’s EPC for rental reasons, or you simply want to reduce your heating bills to balance some of the autumn and winter demands, these tips will be worth your time and money to help you stay on top of home energy cost areas.

Adjoining Buildings and Garages

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Structures neighbouring the home, such as attached garages or sheds, can enable heat loss if they’re not properly insulated and sealed. Warm air can escape from the living spaces of the home into these unheated adjoining areas, so it’s worth checking that these parts of the home are also adequately insulated. 

For shared garage walls and ceilings below unheated lofts, consider adding garage door insulation like fibreglass batting or rigid foam boards, and caulk the edges to contain the heat. You can also seal any gaps in the floor between the garage or shed and the subfloor of the home using caulk or foam. This prevents heat moving through the concrete floors. Make sure that your garage door is well insulated to retain heat, which also makes the interior of your garage more comfortable if you like to use this area for projects or for work. Properly insulating shared surfaces and sealing gaps creates a thermal barrier between the home’s living space and any adjoining unheated structures. This effectively contains heated air in the home and reduces energy waste.


Lofts are one of the most problematic areas when it comes to heat loss in UK homes. Heat rises to the top of the house and can easily escape through gaps in the loft insulation or uninsulated loft hatches. So, to keep the heat in, ensure your insulation meets current building standards by checking its depth and topping up low areas or spots where insulation has shifted. Aim for an even depth of 270mm across the entire loft floor and use insulation supports to hold it in place. Installing a loft hatch insulation kit or weatherstripping around the edges of the hatch and thoroughly insulating the back will prevent draughts from below entering the loft space. Sealing any gaps will also help to stop heat escaping through the loft.

Look for gaps around pipes, wiring, chimneys and other protrusions through the insulation, which can be filled using expanding foam or draught sealing tape, to plug the gaps through which heat can escape. If you live in a semi-detached home, consider insulating the adjoining walls in the loft space to prevent heat loss into your neighbour’s loft. With proper loft insulation, air sealing and closing gaps, you can greatly reduce heat loss through your main roof or conservatory roof and stop wasting money heating your home. 


Credit: Deposit Photos

Particularly in older homes without proper insulation, heat loss through walls can be significant as draughts seep through small cracks and openings. Sealing these gaps and adding insulation where needed improves comfort and efficiency, improving the warmth of your home so you’re less reliant on your central heating. For homes with solid walls, installing internal or external wall insulation is the best way to reduce heat loss and stop draughts. If the home has uninsulated wall cavities, cavity wall insulation can also help contain heat.

Check behind electrical socket covers and light switch plates and install foam pads to seal airflow from these areas if they’re open. You can also use acrylic caulk or expanding foam to seal around plumbing, heating, gas pipes and other pipework where it exits walls, which prevents heat escaping through gaps and keeps the home air-tight. 

Chimney breasts are another common source of draughts in UK homes, but unused flues can be filled with chimney balloons or insulation to stop airflow and keep the room warm in the winter. To block draughts from gaps in the flooring, apply acrylic sealant between floors and skirting boards, or fill gaps with rubber insulation strips that can be fitted into the gaps to block air.

Doors and Windows

Doors and windows commonly experience air leaks, resulting in significant heat loss during winter. Proper weatherisation, sealing and insulation improves their efficiency, so replace any damaged or worn weatherstripping around exterior doors to create a tight seal against draughts. It’s also worth checking the threshold seal underneath doors as well. For glass doors, apply new weatherstripping or replace old door sweeps at the bottom to block the air and the cold.

It’s just as important to inspect window frames for gaps and fill these with caulk or weatherstripping to reduce airflow. Cracked glazing sealant around glass panes is a common problem in older homes, so check these and replace if necessary. If you don’t have double glazing in your property, and the budget doesn’t allow for it to be installed, you can add secondary glazing panels to add warmth, for a budget-friendly and renter-friendly solution. 

Sealing gaps around doors and windows and adding secondary glazing, insulation film or new window units greatly reduces costly air leaks and helps to better insulate and protect a home from the elements. While replacing old single-glazed windows may be a costly endeavour initially, it will save you money in the long-run and add value to the home. 

Preventing heat loss through hidden gaps, cracks and uninsulated areas should be a priority for any homeowner wanting to reduce energy waste. A room-by-room approach allows you to detect specific areas where efficiency upgrades are needed most, improving the energy efficiency of your home and reducing utility bills. 

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