Lime Green turns 21

External Wall Insulation

Warmshell’s external wall insulation system wraps around the exterior walls of masonry or timber frame buildings – making them energy efficient, comfortable and healthy to live in.

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Internal Wall Insulation

Warmshell’s internal wall insulation system is easily fixed to walls and ceilings from the inside. So, if it isn’t possible to fit insulation to the outside of a property, this is the easy, energy efficient alternative.


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Warmshell is the natural, affordable, highly effective wall insulation system.

The perfect complement for the Lime Green range of mortars, plasters and renders, Warmshell uses wood fibre insulation panels, that have exceptional insulating qualities and are also safe, breathable and sustainable. For special situations we have a range of alternative insulations as well.

The ideal wood fibre insulation system for almost any situation

One of the real beauties of Warmshell’s insulation system is its versatility.

Warmshell is used on some of Britain's best-known historic buildings and ecological developments, as well as smaller projects and individual self-builds. It brings benefits to almost any type of building project, including:

  • Interior Internal or exterior external wall insulation
  • Brick, masonry or timber frame buildings
  • Terraced or detached properties
  • Contemporary or traditional designs
  • New build or retro-fitted installations
  • Domestic or commercial premises
  • Hyper-insulated eco-homes or historic landmarks

In any situation, the eco-friendly Warmshell wood fibre insulation systems offer you exceptional levels of insulation, comfort, safety and sustainability – yet surprisingly affordable.

Ask us why Warmshell is right for your project

A Complete Insulation System

Warmshell is more than just a kit. Our Warmshell Warranty means you can be sure our natural, sustainable materials are also the sensible choice.

Lime Green offer a full range of components, and are here to support you every step of the way – from guidance on the initial design and specification, right through to recommendation of suitable installers in your area.

Our team of specialists is only a phone call away, plus we offer useful installation guides and ‘how to’ videos.

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No other type of insulation system brings quite so many benefits

One of the most compelling things about Warmshell is its combination of benefits.

The natural, healthy solution

Warmshell is the natural solution. It uses natural components – primarily wood fibre and lime mortars – with no harmful chemicals or adhesives.

Snug and warm in the winter

The combination of natural wood fibre and hydraulic lime render embedded with recycled glass beads brings outstanding insulating properties – keeping you warm and saving on heating bills.

Comfortable and cool in the summer

As well as locking heat in during the winter, Warmshell also keeps it out during the summer – so your property remains cool and comfortable.

Warmshell Woodifbre has remarkable phase-shift properties, exploiting the natural ability of wood to store heat, which means unlike synthetic insulations it protects you from summer overheating. 

Passivhaus principles

Warmshell lives up to the Passivhaus design principles – reducing the need for space heating and cooling, and bringing excellent indoor air quality and comfort levels.

Superior acoustic insulation

Warmshell Woodfibre offers outstanding sound absorption properties – providing superior protection from both airborne and impact noise.

The benefits of breathability

With Warmshell, your walls can still ‘breathe’, allowing trapped moisture to escape. This prevents condensation, avoids damp, and makes your insulation even more effective.

Sustainably sourced, and environmentally sound

Lime Green's natural lime mortars are manufactured right here in the UK, and their wood fibre insulation panels are sourced from sustainable European forests certified to FSC (Forest Stewardship Council) standards.

Tried, tested and fully accredited

Warmshell is tested under ETAG 004 (European Technical Agreement Guidelines), and has been independently monitored by (SPAB), the Society for the Protection of Ancient Buildings.

Reassuring standards of fire protection

Compared to petrochemical-based systems, Warmshell’s carbonisation properties limit the speed at which fire can spread – and its fire protection qualities have been classified by a UKAS approved fire testing lab.

Surprisingly affordable

As well as being highly-effective, Warmshell is also very affordable – we’d urge you to compare our prices with those of any petrochemical-based alternatives.

Speak to an expert

In business since 2002, Lime Green is the UK's foremost manufacturer of hydraulic lime mortars, plasters, renders and insulation.

"We invest heavily in research and development across key areas like product chemistry, environmental assessment and historic building maintenance."

As a family-owned business, we aim to give you the very best possible service. We provide a wide range of installation guides and ‘how to’ videos. Our experts are on hand to provide advice and guidance.

Contact us to talk through your project.

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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