This website uses cookies to ensure you get the best experience on our website. Find out more.

Wall Insulation

Wall Insulation

Around 30% of heat loss in an uninsulated home can occur through the walls [1]. This has a big impact on energy usage. Insulating your walls could help you save hundreds of pounds on your annual energy bill [1].

Insulating your home helps you maintain ideal room temperatures. This means you won't need the heating on as long.

What is wall insulation?

Wall insulation involves adding insulating materials to your home's walls. This prevents heat loss and heat retention in your home.

Identifying your property’s wall type

Before upgrading insulation, you will need to find out what type of walls that your property is built with. In the UK, there are two main types of walls:

Cavity Walls

Homes built after the 1920s are likely to have cavity walls. These are constructed with two separate walls that have an internal cavity space between them. The outer section or “leaf” is made up of brick. The inner layer is a concrete block or brick. These walls are also known as “hollow walls.”

You can identify what type of walls your home was built with by looking at the outside brickwork patterns. An even pattern laid lengthways with a width over 260mm is likely to have cavity walls.

Solid Walls

If your home was built before the 1920s, it is likely to have solid walls. These types of walls consist of a single wall, usually made of brick or stone, and have no cavity. They are least likely to be insulated. This can cause a significant amount of heat loss.

Solid walls can be identified by their alternating pattern and mixture of short and long bricks. A wall with a width of less than 260 mm and bricks positioned across the wall means it is likely to be a solid wall.

What are the Different Types of Wall Insulation?

Once you know what walls your home was built with, you will be able to select your insulation.

Here are the different kinds of wall insulation available:

Cavity Wall Insulation

Cavity wall insulation involves injecting material into the wall. This could be mineral wool, polystyrene beads or polyurethane foam. Holes are drilled into the wall from the outside to inject the insulation.

The work must be completed by a professional installer. The job takes around 2 hours to complete. You won't see any significant changes to the aesthetics of your property from the drilling.

The cost of cavity wall insulation will depend on the size of your home. It costs between £345-£610 on average [1]. The Energy Saving Trust estimates that installation savings will outweigh the costs within the first five years [1].

Homes built in the last 20 years will have already gone through the process. You can find out if this work has been done previously by getting in touch with your local authority. You can also get a borescope inspection from a registered professional.

Solid Wall Insulation – Internal and External

As solid walls are built with no cavity, there is nowhere to inject insulating material. This means properties with solid walls can only be insulated externally or internally.

Internal wall insulation involves installing rigid boards or stud walls to the inside walls of your home. This tends to be the cheaper option with costs averaging at £7,400 depending on the scale of the job [2]. This will reduce your floor space and the process can be quite disruptive. Professional consultation should advise whether this is the best option for you.

External wall insulation involves fitting of  material onto your outside walls. You would then need to cover it with plasterwork or cladding. This can renew the appearance of your property. It has varied finishes including smooth, tiled, brick-slips and textured.

External insulation will not impact your inside floor space, or cause disruption to your household. It can also improve your homes weather and sound resistance. This may be a good option for a home looking to increase its durability. It adds a layer of protection to the brickwork.

External wall insulation can be expensive. The prices add up to around £13,000 in total [2]. You may be able to lower these costs by completing the work alongside other home improvements. You should check with your local council before getting the work done. Planning permission may be required.

How do I find a wall insulation installer? 

You can find a professional installer by visiting the National Insulation Association (NIA). 

To maximise home insulation saving, it is a good idea to switch energy suppliers. You can get a free comparison today to find out which energy supplier can provide you with the best deal. Visit our energy guides for more information on energy saving.

[1] https://energysavingtrust.org.uk/home-insulation/cavity-wall

[2] https://energysavingtrust.org.uk/home-insulation/solid-wall

Facebook Twitter LinkedIn Pinterest