How is External Wall Insulation Installed?

Can you install it yourself? The answer to this is no. Even if you are competent in completing jobs around your house, the installation of external wall insulation is a specialised skill in both the insulation and rendering elements of the job. The installers who carry out the work have all been trained specifically in its application and it is not worth the risk given the cost in you trying it for yourself.

External Wall Insulation (EWI) – What is it?

Before we can look at how EWI is installed, we should first look at what the product is. EWI is a retrofit insulation product which is applied to the outside of houses to create a warm blanket around its perimeter.

It has a number of benefits to the house. The first of which is the prevention of water penetration into the house as it is made up of layers of insulation, and several rendering layers which most typically use a silicone render to repel water

Secondly, the insulation prevents heat from escaping the external walls of your home, which leaves your home warmer and reduces your heating bills during the winter months. It also has the added benefit of keeping your home cool in the summer months

The third benefit in this busy time we live in, is the noise reduction from outside like passing traffic.

So how much will it cost me?

External wall insulation is not a cheap solution to your home. The country has seen huge retrofit insulation programs to millions of houses for cavity wall and loft insulation but there has been no such programs for the 8 million of so hard to treat properties which cannot have cavity wall insulation so it is left to the homeowner to pay for the works.

Having reviewed the market, the estimated installation costs are:

Type of Property Estimated Cost to install EWI
Mid Terraced £6,000 to £8,000
Semi Detached or End Terraced £8,000 to £12,000
Detached £12,000 to £20,000

So how do I install it?

As we have touched on, External Wall Insulation is a specialised product and therefore you need to seek quotes from specialised companies. They will be able to provide a quote and discuss your needs and explain how the project will unfold. The first step of the system is to ‘enable’ the property which includes removing any fixture and fittings which are attached to the wall.

An insulation layer which is bolted to the outside of the wall, which sits on an aluminium starter track. It is then rendered with two layers of a render basecoat with a fibreglass mesh sandwiched between with a final ‘finish’ basecoat over the top which could be a silicone enhanced render or a spar dash finish. Once the rendering is finished, new window sills are installed and the fixtures and fittings like down pipes and washing line cleats are re-installed to ‘reinstate’ the property.

Next steps…

We have covered here that external wall insulation is a fantastic product. Whether you are a home owner, Landlord, private tenant or even a student tenant you can benefit if the homeowner gives authorisation. So to take advantage of a warmer house and reduced heating bills, it’s time to contact a specialist!