Properly insulating your home helps to keep you warm and comfortable, while also reducing your energy bills and preventing damage that can be caused by cold weather, damp and moisture. While many homes have some form of roof insulation, not enough have adequate wall insulation.

However, if you have been shopping around for wall insulation, you may have found there are quite a few options available to you. Here, we will be taking a look at the best type of insulation for the walls in your home.

Cavity wall insulation

If you have cavity walls, the first thing you need to do is find out whether you have any existing insulation. Cavity walls in new build properties are often built with a layer of insulation board inside the cavity against the inner leaf of the wall. 

Even if there is existing cavity wall insulation, there may be a gap that has been left to prevent moisture transfer. In this case, or with walls that have no insulation in the cavity, the gap can be filled with blown-in insulation.

Blown-in cavity wall insulation is a budget-friendly option that usually uses either loose fill cellulose or fibreglass and can reduce the amount of heat that is lost through the walls and can reduce draughts. 

However, this type of wall insulation does come with disadvantages, such as eliminating the gap that was intended to prevent moisture transfer, and some types of cavity wall insulation can sag over time. So, it’s best to have your walls inspected by an expert first if you decide to proceed with this option.

Internal wall insulation 

If you want to insulate the individual rooms of your home, rather than the outer walls of your home, then you may have looked at internal wall insulation. The most common way to install IWI is by building a new stud wall and then adding insulation made from rigid boards or mineral wool into the cavity between the new and existing walls. This results in better soundproofing between rooms, as well as better heat retention inside them.

The main disadvantage with this option is that your rooms become smaller to accommodate the new structure. Plus, if you choose a wall with fixings or electrical fittings, these will need to be removed and rewired through the new wall. It can also be a very disruptive process, taking the rooms out of commission while the work is being completed.

External wall insulation

By far, the best type of insulation for walls is external wall insulation or EWI. This method uses a layered system of thick insulation board, glass fibre mesh and render to apply insulation to the exterior walls of the property which is then covered with a decorative finish.

External wall insulation is one of the best methods to improve your home’s thermal efficiency, meaning that your rooms will better retain heat in the winter and even stay cooler in the summer. EWI can reduce your annual heating bills by up to 50% while also preventing damp and condensation.

Compared to internal wall insulation, the installation of EWI is much less disruptive as all the work is carried out externally and the finished product doesn’t result in reduced interior space. EWI also reduces noise pollution and allows you to redecorate your home’s exterior as part of the process.


When it comes to the best type of insulation for walls, you don’t need to look further than external wall insulation. It is the best option for external walls and, if you have EWI in place, you shouldn’t need to worry about insulating internal walls, because the heat inside your home will be so well-maintained. 

EWI can also be used in conjunction with cavity walls, so even if you have cavity wall insulation, you can further bolster your home’s thermal efficiency by adding EWI!

If you think external wall insulation would be a good fit for your home, please get in touch, and see how we can help.