Are you about to buy a heat sink?

Are you worried that the house you’re about to buy will be a heat sink? How can you make sure your flat isn’t a heat sink?

Here are a few simple checks you can carry out yourself.

Look at the year of construction

Some houses are more prone to insulation problems than others. Before embarking on a detailed diagnosis of your home, take a look at the year it was built:

– Before 1948: Buildings at this time were constructed using materials that did not provide much insulation, although thick stones were always better than bad concrete;

– Between 1948 and 1975: these materials were abandoned and replaced by rapid construction solutions with very poor performance;

– After 1975: following the first oil crisis and the introduction of the first thermal regulations in 1974, homes are gradually becoming better insulated.

In fact, Engie ¹ states that “in a house built before 1974, at least 25% of heat loss is due to poor roof insulation, 10% through windows, 20% through walls and 10% through the floor”.

Track down draughts in your home

First of all, it’s important to be aware of your home’s weak points. In other words, the holes that make your house a thermal strainer. Insulation problems can occur where walls meet windows, the roof, the floor or the balcony. These are known as thermal bridges.

💡 Here’s a pro tip: light a candle and move it slowly close to your walls. If the flame flickers, it’s a sign of air infiltration.

Keep an eye on your heating bill

Heat loss, which is both a symptom and a cause of poor insulation, keeps your heating system running all the time. This leads to an even more acute problem with galloping inflation: high heating bills.

In addition, Anah ² offers advice on how to reduce your energy bills

Look, touch and smell

To recognise poor insulation, a few simple steps can make all the difference.

• Cold walls. Run your hand over the walls. If they’re cold, your home is probably poorly insulated.
• Traces of damp. If your home is damp, this is a symptom of poor insulation. Check the walls for mould stains. Bad smells or condensation also suggest that your home is a heat sink. There may also be a ventilation problem.
• The general condtions of the building. What condition is the roof in? And the facade? Sometimes, installing double-glazed windows won’t solve the problem if the cause is more global.

Carry out an EPD

If you want to know whether your home is an heat sink or not, only a professional can asnwer this question. You need to have an energy performance diagnosis (in French “Diagnostic de performance énergétique – DPE) carried out.

This document enables you to estimate your home’s energy consumption. It’s an essential tool for identifying the weak points in your home. It allows you to find where the issues are and how to fix them. As a reminder, a home with an F rating (330 kWh/m² per year) or above is an heat sink.

Choosing the best company for energy renovation work.

If all the indicators are in the red, you have no choice. To insulate your home properly, live comfortably and avoid paying exorbitant bills, you need to carry out work.

And that goes for landlords too. As part of the Climate and Resilience Act, “From 2025, it will be forbidden to rent the worst insulated thermal flats (rated G), and from 2028 for the rest of the flats (rated F). And from 2034, it will be homes classified as E (an addition voted for by MEPs) that will be banned from being rented out.