Thermal insulation is essentially the reduction of heat transfer between objects, or the transfer of thermal energy from one place to another.
With recent rises in energy prices in the UK, preventing heat loss from your home is more important than ever. As prices go up, we are naturally looking for ways to reduce the need to rely on gas and electricity to heat our homes.
If a large amount of heat is lost from your home quickly, likely due to poor insulation, your home will be colder, and you’ll need to spend more and more money just to simply heat up your rooms.
Heat can be lost from your home via various avenues, such as the walls, roofs, floors, and windows. It can be a big problem in the winter which causes the inside of the home to be too cold, but it’s also an issue in the summer too, as too much heat makes its way into the property as well.
The point of thermal insulation is to prevent too much heat from leaving the home AND too much heat from entering the home, dependent on the weather and time of year.
There are many different areas of the home that can be insulated, including the floors, cavity walls, external walls, and lofts.
Thermal floor insulation
Around 15% of the heat in your home can be lost through the floor, so installing the right floor insulation is crucial. It can be placed underneath the floorboards in any room of your home, regardless of whether it’s on the ground floor or the first floor.
Installing floor insulation has a number of great benefits, including preventing unwanted heat loss and offering soundproof acoustic protection too, which stops noise from travelling between floors, something that’s particularly important for the first floor or higher.
Thermal loft insulation
Even more heat leaves the home via the roof, closer to 25%. It’s no secret that heat rises, so looking to insulate your loft and roof area is extremely important whether you’ve moved into a new home or are making improvements to your current property.
Loft insulation is often made from glass wool or mineral wool and can be installed yourself with relative ease, or you can call in a professional to help. Once installed, loft insulation can help prevent heat from rising through your loft or roof and leaving the building.
Thermal cavity wall insulation
Most homes that were built after 1920 have walls that are made of two layers with a gap or cavity between them. Cavity wall insulation is thus installed to fill in the gap and to help retain heat and save energy.
It’s estimated that around 33% of heat loss in the home is through the walls, so it’s vitally important to insulate them properly. This can be done using insulation board, rolls or foam.


Thermal external wall insulation
If your home has solid external walls, then insulation board can be used to efficiently insulate the home and reduce the percentage of heat that is lost through the walls.
Solid external wall insulation is advised for a number of reasons, including reducing draughts, saving space, increasing the expected lifespan of the wall and does not disrupt the home during its installation.
What influences thermal insulation performance?
- Thermal conductivity
- Surface emissivity
- Thickness of insulation
- Density of insulation
- Specific heat capacity
- Thermal bridging
You can also follow some of our other guides such as how to inspect the existing insulation in your home, as well as how to save energy with insulation.