External Wall Insulation

What is External Wall Insulation?

External Wall Insulation is a form of cladding that is fixed to the exterior of buildings to improve the energy efficiency and appearance of your home.  Although 'cladding' carries negative connotations recently from the press, it is important to note this type is not the same as the cladding used in tower blocks such as the Grenfell tragedy. All of the the insulation methods we use from our suppliers are BBA approved and deemed safe and suitable for installation for UK properties. 

External wall insulation used to be most suited to those with solid wall houses, but with the general consensus of improving our energy ratings, there has been an increase in property owners installing EWI alongside their existing cavity wall insulation. 

Advantages of External Wall Insulation

  • Aesthetically pleasing after decorative top coat

  • Can cut costs of energy bills and improve EPC Rating 

  • Non disruptive as all works are carried out outside the home

  • Breathable and damp resistant

  • Low maintenance and compatible with practically any property 

  • Unlike cavity wall insulation, external wall insulation requires no internal space

  • If using mineral insulation, can benefit from soundproofing qualities

  • Can increase the value of your property in energy efficiency and appearance

  • No restrictions on thickness of insulation (unlike cavity wall insulation) can be installed up to 200mm

Screen Shot 2020-02-25 at 14.34.56.png


Expanded Polystyrene Sheets

Expanded polystyrene: 

This is the most common material used for external wall insulation as it is very cost-effective, easy to install and has excellent thermal efficiency.


£2.50 per m2

Screen Shot 2020-02-25 at 14.38.04.png


Rockwool Insulation

Mineral Insulation is completely breathable (when used in conjunction with a silicone or mineral render system) Non combustable. 


£11 per m2

Screen Shot 2020-02-25 at 14.39.46.png


Kingspan K5

Premium insulation board, ideal where space is limited - compressive strength and so acts better where there is a risk of mechanical impact such as close to public footpaths or roads. Ideal for new builds and refurbishments


£9.50 per m2

What are R Values and U Values!?

You may have heard phrases such as 'Improve your U Rating' but what does all of this actually mean? Aside from building standards and regulations where such values need to be compliant, these values essentially reflect how well insulated the building elements of your property are. 


Thermal insulation is measured by its ability to restrict heat transfer through thermal conductivity and thermal resistance. 


The K Value (or otherwise known as Lamda value) which is measured in watts, shows how long a material can conduct heat. The lower the K Value, the lower the heat loss. 


The R Value, measures how well a material resists heat transfer and at a specific thickness.  A good insulation will have a higher R value, indicating it is better at reducing heat loss. 


Lastly the U Value is the sum of the thermal resistencies of all of the layers that make up building elements. The U Value shows the ability to transmit heat from a warm space to a cold space and vice versa. The lower the U Value, the better insulated the building element.

What is an EPC Rating?

An EPC rating is a review of a property’s energy efficiency. They’re mostly used by potential buyers or renters to see how much their energy bills would cost in the new property. Every house needs to have a valid EPC before it can be sold, once you have made home improvements you should have a new survey carried out to reflect your new score. The higher the score, the better the rating. Your EPC Certificate can be found here