Warmshell External Insulation

Warmshell external insulation is a highly effective EWI (External Wall Insulation) system that is fitted to the outside of your property – making it significantly warmer and more comfortable to live in.


The system comprises of three main components:

  1. Natural wood fibre insulation boards – in a choice of thicknesses
  2. Specialist fixings – to suit the specifics of your building
  3. Traditional lime render – in a range of colours and textures


Your internal floor area stays exactly the same, with no disruptive works inside, or redecoration needed afterwards.

And, by choosing the right thickness of wood fibre insulation you achieve the highest standards of thermal efficiency in a way that suits your home and your budget.

Warmshell external insulation enhances the appearance of your home. You can choose the look and colour you want. And, because our renders are so good at resisting stains and the build-up of mould, your property can will look great for decades to come.


Ideal for many different types of property

You can use Wamshell external insulation for almost any type of property:

  • Brick, masonry, solid wood or timber frame buildings
  • Contemporary or traditional designs
  • New build or retro-fitted installations
  • Domestic or commercial premises
  • Hyper-insulated eco-homes or historic landmarks

To benefit, you just need to be able to get access to the exterior of the entire property and abide by any applicable planning restrictions.

But, of course, if you have a terraced or semi-detached property, live in a conservation area, or simply want to retain the existing look of your house, you can still benefit from our interior internal installation systems.

Warmshell for new timber frame buildings

Unlike standard methods of timber frame insulation (where the insulation in-fills just between timbers), Warmshell external insulation completely encases the property.

This offers a number of significant advantages.

You can expect a Warmshell wall to be warmer, more airtight, and have better acoustics than a standard timber frame design. In practice this means that a wall as thin as 260mm will meet Building Regulations standards (0.18 U Value) without the need for additional waste water heat recovery systems or triple glazing.

Warmshell for historic timber frame buildings

Warmshell is an ideal way to upgrade the thermal performance of existing timber frame buildings.

Also, breathability is vitally important in historic buildings, as are hydroscopic materials that buffer moisture, protecting delicate structures from decay. So, Warmshell creates a breathable yet airtight envelope around the building – virtually eliminating thermal bridging and drafts, which can seriously compromise energy efficiency.

Warmshell for brick or masonry buildings

Warmshell exterior external insulation is a fantastic way to make brick or masonry buildings significantly warmer and more comfortable to live in. 

By their very nature, these buildings tend to be less thermally efficient. So, by creating a Warmshell envelope around them, you benefits from gain significant benefits. Yet,With the breathability of wood fibre and hydraulic lime mortars, the structure of the building is protected from the build-up of condensation or damp.  

Warmshell for solid wood buildings

Warmshell is an ideal way in which to insulate and add weather protection to buildings constructed from solid wood or cross-laminated timber (CLT).

These CLT structures are made up of large load-bearing engineered timber panels that are light, stable and very strong. A quick method of construction constructing CLT is used to build entire structures. Openings, such as doors and windows, are incorporated within the panels – and Warmshell is then used to encase the whole structure making it warm and dry, and minimising the type of thermal bridging that can be a problem with some CLT structures.

Achieve the look you want

With the Warmshell external insulation system, you can enhance the appearance of your home – irrespective of whether the look you want is contemporary, rustic or traditional.

One of the benefits of Warmshell is that you can mix-and-match from the range of Lime Green lime renders. You can select from several different textures and many different colours.

And, to help you make your choice, we can always provide sample bags to help decide on the texture, colour and style of lime render finish you want.

Benefit from our installation expertise

Installing our Warmshell exterior external installation system is a straightforward process, but we would urge you to take full advantage of our training and support – or to call on the wide network of system-trained installers.

For builders and plasterers who are interested in learning more about installing Warmshell, we offer regular training days at various locations so you can become a certified installer.

Training covers important topics, such as:

  • How to make watertight junctions at eaves and window reveals
  • How to fit it around window sills
  • How to choose the right types of fixings beads and trims

Also, there are some significant differences in approach depending on the type of property.

Warmshell Exterior Documents

We are here to support you throughout the installation process. Download our installation guide. And, if you ever want more advice and guidance, give us a call.

We are here to support you throughout the installation process.

See all our guides

Become a Warmshell partner

With Warmshell, installation is straightforward.

But, to help you on your way, we also offer training, and can put you in touch with a wide network of system-trained installers.

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