What is the Thinnest External Type of Wall Insulation? 

Many homeowners want to enhance their property’s energy efficiency, particularly during colder months. They seek solutions like external wall insulation to achieve this goal. However,  finding the thinnest external wall insulation can be a challenge. 

Let’s discuss the thinnest external wall insulation options available. Read on to learn more about these innovative solutions and how they can benefit your home.

Understanding External Style of Wall Insulation Thickness

External wall insulation thickness is about how wide the insulation is across the wall. This measurement shows how well the insulation can stop heat from escaping.

Several things affect how thick the insulation needs to be. These include how well the material can stop heat, the weather, and how much energy you want to save. Common insulation materials like mineral wool or stiff foam are usually between 50 to 150 millimetres thick.

In places where there’s not much space, thin insulation is handy. These thin options let you fit them in tight spaces or keep the outside of the wall looking nice. Finding the right balance between thickness, how well it works, and any limits you have is vital for saving energy.

The Benefits of Thin External Insulation

While standard external wall insulation materials offer excellent thermal performance, ultra-thin insulation solutions provide additional benefits:

  1. Thin insulation solutions are ideal for tight spaces or heritage buildings where minimising the impact on interior living space is crucial.
  1. Thin insulation minimises the protrusion from the existing wall by requiring less material which preserves the aesthetic appeal of the building.
  1. Ultra-thin insulation can be more cost-effective than traditional options, especially for smaller projects with less material required.

Types of Ultra-Thin External Insulation Materials

Several innovative materials have emerged as ultra-thin external wall insulation options, each with its unique properties and applications. Here’s a side-by-side comparison of the thermal performance, thickness, and other relevant factors for the ultra-thin insulation materials discussed:

Insulation MaterialThermal Conductivity (W/m·K)Typical Thickness RangeCostAdvantagesDisadvantages
Aerogel insulation~0.01510 – 20 mmHighExcellent thermal performance, ultra-thinHigher cost, fragile, potential moisture issues
Vacuum insulated panels (VIPs)~0.00410 – 20 mmHighExceptional thermal performance, ultra-thinHigher cost, potential air leakage risks, limited availability
Thin mineral wool boards~0.03525 – 50 mmModerateGood thermal performance, more affordableThicker than aerogel or VIPs
Thin rigid foam boards~0.025 – 0.03525 – 50 mmModerateGood thermal performance, more affordableThicker than aerogel or VIPs

Aerogel insulation is often used in combination with other insulation materials or as part of a composite system while vacuum insulated panels (VIPs) VIPs are commonly used in retrofit projects, new construction, and applications where space is limited. 

Proper handling and installation techniques are essential to maintain the vacuum seal and insulation performance.


If you are looking for the thinnest insulation for your outside walls, Aerogel insulation and vacuum insulated panels (VIPs) stand out as your perfect choice. 

These cutting-edge insulation materials may cost more upfront but their ability to save valuable living space and maintain the look of your property can make them a worthwhile long-term investment. 

Let us know if you need help with this type of project. We can help you start your journey towards a more energy-efficient and comfortable living space while respecting the unique constraints and characteristics of your property.

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