22nd Nov 2022 -

External wall insulation is ideal for reducing the problems caused by wind and low temperatures, especially in buildings with multiple occupants and those in urban areas. There are many advantages to insulating an external wall. Solid brick walls are sturdy, but do not hold warmth - so insulation is a good solution. Insulation for external walls can be placed within the cavity of the wall, but properties built prior to the 1930s don’t have cavities, so the insulation would need to be fixed to the outside of the building, and this is known as external wall insulation.

What is External Wall Insulation?

External wall insulation is an insulation system that fits the outside of a building, unlike the insulation you might see on internal walls. Wall insulation on exterior walls is suitable for the following settings:

  • Flats and apartment buildings: Shared accommodations such as flats are often smaller and less energy-efficient than houses, so using external wall insulation is easier and less disruptive than installing it internally.
  • Outbuildings and sheds: Whether you have a barn conversion, yoga studio, home office or another outbuilding, your structure will be much more habitable with external wall insulation, without affecting the appearance of the inside.
  • Farm buildings: Agricultural and farm buildings can greatly benefit from insulated external walls. Livestock, machinery and supplies are much better protected from the elements with external insulation.

There are several advantages and drawbacks to external wall insulation. As suppliers of a wide range of building materials, including many types of insulation, we understand the nuances of external wall insulation and other materials. 

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What Are The Benefits of External Wall Insulation?

If you are creating external wall insulation systems you will get a lot of advantages beyond greater comfort and habitability. There are many more amazing benefits to external wall insulation including the following:

  • Lower fuel bills: External wall insulation has many of the same benefits as internal wall insulation, the main benefit of which being less energy consumption - so you can lower your fuel bills.
  • Aesthetics: You can easily improve the appearance of a building with external wall insulation. Appearances can increase house prices in the UK, so it is well worth investing in a building's aesthetics. 
  • Less damp: Damp problems can affect any building, but insulation can help. A thick layer of insulation serves not only as a thermal warmer but also as a moisture barrier, which is great for mitigating the problems that can result from dampness.
  • Environmentally friendly: Insulation materials will make a building more energy-efficient, which is good for the environment. You get cooler summers and warmer winters from external wall insulation, so it is good for all seasons. 
  • Floor space: The thickness of wall insulation can influence floor space, which is annoying for apartment buildings that are much smaller than a typical house. 
  • Increase building lifespan: You can prolong the life of a building with external wall insulation. Insulation can easily be replaced and repaired, which means that the external walls are protected at all times.
  • Increase house prices: Insulation products are not purely functional, they are also an investment. Well-insulated properties command higher prices, so you will get a good return on your spending when it comes time to sell.
  • Low disruption installations: For large buildings in particular internal wall insulation projects present a problem in terms of disruption. External wall insulation avoids this issue and is less annoying for residents.
  • Acoustic insulation: The noise from a large urban area, such as from passing cars and public transport is a nuisance for many people. External wall insulation limits the effects of external noise. 

You can see there is more to be gained from insulating external walls than you might expect. The scale of the project can make it challenging to complete, but the benefits of external wall insulation usually outweigh the drawbacks.

insulation boards

Disadvantages, Costs and Government Grants

The costs of the project will depend on how much insulation you are using. Large projects can become particularly cumbersome financially. There are a few drawbacks to external wall insulation, which many people neglect to consider. 

  • Covering building features: You might find external wall insulation affects the character of a building. You would ruin the look of an old cottage with external wall insulation, so it may not be a wise choice.
  • Cracking: With full exposure to the element, pieces of insulation can crack and might require maintenance down the line. Internal wall insulation does not have this problem.
  • Installation time: While the installation is non-disruptive to the inside of the building, it can take a long time to complete external wall insulation projects - this means having scaffolding up for longer.

Government grants for enhancing existing buildings are available, you can apply for the Green Homes Grant, providing you pass the governments eligibility criteria, and get up to £5,000 towards your project. Wall insulation grants can be difficult to get and will not normally cover the costs of an entire project.

Types of External Wall Insulation Systems

There are layers of insulation fixings, primer and adhesives - but the types of systems for external walls essentially rely on the insulation material itself and a covering render. We offer many types of external wall insulation that are suitable for a wide variety of projects. 

There are a lot of types of external insulation and render and that will provide the benefits described above to a building. Good options include the following:

  • Expanded polystyrene (ESP): By packing together polystyrene tightly into boards, you get a very lightweight and highly effective form of insulation that can be clad onto the outside of a building very quickly and easily.
  • Acrylic render: An acrylic render is a cost-effective way to finish any type of external wall insulation. Using an acrylic render will provide flexible colour options too, which is important to maintain the design style of a building.
  • Wood fibre: Wood fibre insulation is a sustainable form of external wall insulation, so a good choice when you are looking to boost your green credentials. One drawback is that wood fibre can be very heavy to install. 

External wall insulation is more like cladding, so systems that use foam insulation, such as those normally used for a filled cavity wall, are unsuitable. Solid wall insulation is the type of insulation system to use to external walls, with rendering adding a final finishing touch. 

Aside from the appropriate type of insulation, you will also need fixings, screws and other accessories to fix the insulations boards in place. Getting shoddy materials reduces the effectiveness of insulation, so you need to find a reliable supplier.

External Wall Insulation Explained

External wall insulation is not the best option for every project, but certain types of buildings such as flats can benefit greatly. With varying thicknesses, the insulation may stick out on buildings such as terraced houses so it may not be the best option in such cases.

We supply a range of building materials including external wall insulation and can help if you have problems with unreliable, uncommunicative suppliers. For professionals, we'll get you everything you need through our dedicated trade accounts.

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