When people think about electrifying their homes, they often imagine solar panels, heat pumps, electric vehicles or smart technologies. Yet before investing in any of these solutions, there is one question worth asking: how much of the energy you already use is simply escaping through the walls, roof, windows and floors?
In this episode, Adrian explores one of the most important – and often least glamorous – aspects of home electrification: insulation.
The case for insulation
The logic is simple. Every unit of energy that remains inside the home is energy that does not need to be produced, purchased or stored. A well-insulated home requires less heating in winter, less cooling in summer and allows technologies such as heat pumps to operate much more efficiently.
There is no single way to insulate a home. Heat can escape through multiple parts of a building, meaning homeowners have several options available depending on the age, design and condition of their property.
Walls are often one of the biggest sources of heat loss. In older homes, particularly those built before modern energy efficiency standards, external walls may have little or no insulation. Adding insulation to these walls can dramatically improve comfort and reduce heating demand. However, it is also one of the cheaper renovation measures. If a wall has no windows or doors and can be insulated relatively easily, costs reach around €300 per square metre to achieve a good standard of insulation.
The price of insulation materials is also influenced by global events. Many insulation products are derived from petrochemicals or require significant amounts of energy to manufacture. As a result, fluctuations in fossil fuel prices or geopolitical tensions affecting energy markets can directly impact renovation costs. In a globalised economy, events taking place thousands of kilometres away can end up affecting the cost of improving a home in Brussels.
Not every insulation measure requires a major construction project, however.
What’s worth it and what’s not?
One of the most cost-effective interventions Adrian takes you through in this episode is insulating the ceiling of the basement. Because the basement ceiling is effectively the floor of the living space above, adding insulation here immediately reduces heat loss through the floor. Unlike wall renovations, this measure often requires no plastering, painting or major finishing work. It can be installed relatively quickly, causes limited disruption and delivers immediate comfort improvements by making floors noticeably warmer during winter.
Windows are another critical area. Even in homes with decent wall insulation, poorly performing windows can allow significant heat losses and create uncomfortable drafts. Replacing old windows with modern double or triple glazing can substantially improve energy performance, although this can be a significant investment.
Interestingly, Adrian also learns that not all solutions are expensive. Sometimes relatively small interventions can make a noticeable difference. Simple measures such as improving seals around windows, reducing air leakage or installing a small insulating strip beneath a window frame can improve comfort and reduce drafts at a very modest cost. While these measures may not dramatically change an EPC score, they often provide an attractive return on investment.
The roof is another area that deserves special attention. Because warm air naturally rises, poorly insulated roofs can become one of the largest sources of heat loss in a building. In many older houses, roof insulation is either insufficient or completely absent. As a result, roof renovation often becomes a priority for homeowners seeking to improve their EPC rating and reduce their heating bills.
For Adrian’s home, which started with an EPC rating of F, insulation represents one of the most effective ways to improve energy performance. While technologies such as heat pumps are central to electrification, their benefits are maximised when installed in a building that retains heat effectively. A heat pump operating in a poorly insulated house must work harder and consume more electricity to achieve the same level of comfort.
This highlights an important lesson for anyone considering electrification: the cheapest energy is often the energy you never need to consume in the first place.
As Adrian continues his renovation journey, he is beginning to understand that successful electrification is not only about replacing fossil fuel technologies with electric alternatives. It is also about reducing energy demand, improving building performance and ensuring that every euro invested delivers the greatest possible benefit.
Have a question? Drop it in the comments on LinkedIn or YouTube, or get in touch with the Electrification Alliance directly. As Adrian puts it: we’ve got you covered.