Heat loss in your home: 7 solutions to limit your losses

Summary, by the radiator

Heat loss creeps in everywhere, through the roof, walls, windows, floor, and ventilation, and your boiler works overtime to maintain a semblance of warmth (you can also feel the breeze greeting your toes).
Diagnostics, from the candle test to thermal imaging, shed light on actual drafts, and unsurprisingly, it's better to play detective before redoing everything.
Insulation is the great adventure of a cozy home, but beware of false leads, shoddy materials, and professionals who must be chosen carefully, otherwise the heat will escape.

Imagine this strange scene: the heating is working hard, yet the room remains lukewarm, as if the walls are struggling to keep out the winter chill. You feel a draft creeping insidiously under the door, and the pale light fails to warm your numb hands. This is when a thermal curtain becomes essential!

Do you sometimes wonder whether making a home comfortable really depends on technology or pretty cushion colors? No, often not. The cold doesn't chase away dreams, but it gradually erodes your habits, until the moment when you realize that diagnosis shines a light on the real problem. Ready to choose the best thermal curtain to keep out the cold?

The phenomenon of heat loss in the home

Whether your home is insulated or not, its flaws will become apparent. Heat loss manifests itself as a persistent draft, warm air escapes as soon as there is a thermal bridge, and your bills inevitably rise. You may think you are keeping energy inside your walls, but physics always takes the easy route. Heat flows where it encounters the least resistance, and the slightest flaw can ruin your indoor comfort. There's nothing less satisfying than investing in a sophisticated heat pump if your walls let everything escape to the outside.

The definition of heat loss and its implications

You can feel the heat escaping, can't you? But there remains the nagging question of where the loss begins and how extensive it is. The 2026 thermal regulations now address the management of each flow, without tolerating any approximation. Thus, simply installing a thermal curtain is never enough; it acts as a band-aid but does not close the structural wound.

The main causes of heat loss in homes

You identify the causes, then they repeat themselves. A porous wall, an old window, or a frosty floor in January—yes, every flaw accentuates the indoor greenhouse effect, and the boiler fights relentlessly against multiple fronts. The cold seeps in, you hear it at night, and you begin to suspect the complexity of the problem, far from a simple temporary weakness.

The role of different areas of the house in heat loss

Take a break, visualize the entire building, and think about molecular diagnostics. Available calories escape through the roof, your walls compete with the competition, and then the ventilation and glazing, though discreet, compromise your comfort. If you want to see the figures, I've included them below. They're surprising and real.

House area	Loss percentage (%)
The roof	25 to 30
The walls	20 to 25
Ventilation and air leaks	20 to 25
The windows	10 to 15
The ground	7 to 10

You read that right, each area adds to the overall loss. Diagnose where it seems insignificant to you, surprises always occur where you let your guard down.

Diagnosing heat loss in your home

Every home hides its signals. You notice that radiator blazing away, yet the wall remains ice cold. Condensation dares to form on the windows, the bill climbs, and your hands desperately search for the source of the problem. Sometimes you try the old-fashioned method, your hand pressed against the door, a candle to sharpen your instincts. The result? No, you're not dreaming, there is an imbalance.

Tools for measuring heat loss, from handheld to thermal imaging cameras

You try out several approaches, driven by curiosity. Your hand guides you to the cold spot, a sometimes frustrating game. The thermal camera finally gives you the technical image you need, with the weak spot highlighted in bright orange, almost dramatically. Even a comprehensive, costly energy performance diagnosis is a necessary step to get a clear picture and apply for any subsidies that may be available. The effectiveness of your future work starts here.

Type of diagnosis	Accuracy	Indicative cost	Benefits
Simple test (hand, candle)	Low	Free	Quick and easy
Amateur thermal camera	Average	$50-$300	Precise location of thermal bridges
Professional energy performance certificate	High	$150-$350	Required for assistance, comprehensive assessment

You always prioritize a diagnosis before breaking anything.

Seven solutions for reducing heat loss in a home

Your roof is sometimes the silent culprit. Install effective glass wool insulation and the interior will take on a whole new thermal dimension. The investment may seem substantial, but the return on investment will be obvious from your next energy bills. There is rarely a simple solution that does not involve this strategic area.

Improving wall and floor insulation

You tackle the walls, those giants that we neglect. External insulation is winning over many experts. The floor also disrupts the descriptive balance. A simple insulator, in roll or technical panel form made from wood, transforms your winter mornings. Your home takes on a new thermal dimension. The nature of the coverings weighs heavily in the equation.

Window replacement and glazing management

You then turn your attention to the glazing. Single glazing will ruin your efforts, whereas double or triple glazing, installed correctly, will block out that creeping cold. You caulk, you test, you even add a discreet silicone seal, and the draft disappears. Replacing a window is never just about aesthetics. It's about long-lasting performance.

Other complementary actions to limit waste

You fine-tune the ventilation settings, check every seal, and hunt down the slightest flaw. Dual-flow ventilation now plays an active role in thermal stabilization, a silent revolution. The heating system must be optimized in conjunction with the rest, otherwise the overall result will be disappointing. You will see the difference in your bill the very next month.

Criteria for selecting and evaluating the effectiveness of solutions

Before selecting a solution, you always consider the cost-benefit ratio. External insulation costs around €150/m², while the price of high-performance windows varies considerably. Subsidies in 2026, which are more accessible than in the past, contribute to the overall effort. You may sometimes be eligible for a subsidy known as MaPrimeRénov’ or an adapted Energy Efficiency Certificate (CEE), which can significantly alter the profitability calculation.

Mistakes to avoid when renovating for energy efficiency

Sometimes you doubt yourself, underestimating the complexity of a thermal renovation. You insulate partially, the thermal bridge reappears further on, moisture sets in, disappointment ensues. So you check your surfaces, your choice of materials, the consistency of your project, and each point then becomes obvious. The initial diagnosis remains your first weapon.

Choosing qualified professionals for the work

You look for a tradesperson with the RGE label, you read reviews, you ask specific questions. You compare guarantees and demand certification. In 2026, the quality of workmanship will determine your access to financial assistance and the end result. Choosing the right professional will save you a lot of trouble.

A quiet and efficient home with Nokomis

You rub your hands together in the evening, and the cold no longer disturbs your peace of mind. The house vibrates differently, silence settles in, and the performance produces no unsightly noise. Dominated by the regularity of the temperature, your daily life is transformed. You then feel this mixture of warmth and serenity, the indoor environment is balanced, and you wonder if this well-deserved comfort hides a subtle form of modern luxury.

Learn more about heat loss

How can you tell if you have heat loss?

Last winter, while doing some DIY around the house, I was surprised to feel a draft near the windows. Infrared thermography is a bit like a magnifying glass for the avid gardener, but for the home. With a thermal camera in hand, clever thermal bridges are revealed, creating a detective-like atmosphere with thick socks, a real heat recovery mission, and a real Sunday morning DIY hack.

Which part of the house loses the most heat?

Frankly, the roof is like grated cheese on a Sunday quiche—it lets nearly 30% of the heat escape from the house. When I go up to the attic in winter, it's like sticking my nose outside without a hat—it stings. House, garden, it's all about insulation, DIY, and tricks, even if it's just an extra blanket.

What is the percentage of heat loss in a house?

So, between the roof, the walls, and the air that leaks in, an old house can sometimes be a real festival of heat loss. The figures? Between 25 and 30% through the roof, 20 to 25% through the walls or air, like a vegetable garden dripping in the summer rain.

Calculate the heat loss of a house?

It feels a bit like doing math on a Saturday morning in your pajamas, sitting at the living room table with a mug in your hand. For 100 m² of wall, U coefficient 0.3, temperature difference of 20, the calculation gives 0.3 x 100 x 20, or 600 watts. Home improvement, DIY, a real tip that's been tried and tested, like the carrot cake recipe that you adapt to the season.