Vapour-open. Retrofit-safe. Architect-trusted.

Sisalwool is the natural fibre insulation designed for a buildings fabric, not just building regs. Breathable, sustainable, and designed for longevity, it’s trusted by conservation architects, retrofit specialists, and low-energy designers alike.

Why Sisalwool?

Vapour-open + moisture safe

Sisalwool works with the building, not against it. It’s breathable, moisture diffusing and safe for solid wall retrofits, listed buildings, and low-intervention conservation projects.

Designed with design in mind

From barn conversions to winter gardens, Sisalwool fits the brief where exposed materials, low-embodied carbon, and natural finishes are required. It friction-fits easily, performs quietly, and looks rustically beautiful when left visible.

Truly sustainable specification

A blend of sheep’s wool and sisal fibres, Sisalwool is non-toxic, 100% recycled and end-of-life recyclable. We use up-cycled clothing off cuts, such as Harris Tweed and partner with circular supply chains across the UK.

Trusted by technical teams

Backed by moisture modelling guides, compatibility testing, and robust in-situ performance. When breathability, thermal performance, and natural material integrity matter, Sisalwool delivers.

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