Sustainable insulation · UK installer
Sustainable insulation that's carbon-negative — and outperforms foam.
Most insulation is petrochemical foam. Ours is sprayed cork — a genuinely carbon-negative natural material that insulates, weatherproofs and refinishes your walls in one pass. Breathable, fire-rated, and built to last 40+ years.
Why sustainable insulation matters
Insulating a building shouldn't wreck the planet.
Roughly half the embodied carbon in a typical UK retrofit comes from the insulation itself. PIR boards, EPS foam, polyurethane sprays — all are oil-derived, energy-intensive to manufacture, non-recyclable, and release toxic compounds in a fire. Choosing sustainable insulation cuts the lifetime carbon of the upgrade by 60–90%.
Sprayed cork is harvested by hand from the bark of cork oaks — without felling the tree. The bark regrows in 9 years. A harvested oak then stores up to 5× more CO₂ than an unharvested one. Cork oak forests across Portugal and Spain absorb an estimated 10 million tonnes of CO₂ every year. That's the supply chain behind every wall we coat.
Sustainability credentials
Carbon-negative, breathable, recyclable.
Carbon-negative
More CO₂ sequestered in growing the cork than emitted in manufacture and transport.
No tree felled
Bark is hand-stripped; trees regrow it every 9 years across a 200-year life.
Recyclable & biodegradable
End-of-life cork can be reground or returned to soil — no landfill.
Vapour-permeable Class 1
Breathable system. Prevents the interstitial condensation that ruins foam-insulated walls.
Fire-rated B-s1, d0
Tested to EN 13501. Suitable for residential, commercial and over-11m where compliant.
25-year warranty
Manufacturer-backed. Engineered for a 40+ year service life with no repainting.
Sustainable insulation FAQs
Common questions, honestly answered.
- What is sustainable insulation?
- Sustainable insulation is insulation made from renewable, low-embodied-carbon materials — typically natural fibres (sheep's wool, hemp, wood fibre, cork) rather than petrochemical foams (PIR, EPS, polyurethane). The best sustainable insulation is also recyclable or biodegradable at end of life and breathable in service, so it doesn't trap moisture inside building fabric.
- Which is the most sustainable insulation material?
- Cork is one of the most genuinely sustainable insulation materials available. The bark is hand-stripped from cork oaks without felling the tree, regrows naturally every 9 years, and a harvested oak stores up to 5× more CO₂ than an unharvested one. Cork oak forests collectively absorb around 10 million tonnes of CO₂ each year. Cork is also recyclable, biodegradable, and Class 1 vapour-permeable.
- Is sustainable insulation more expensive than standard insulation?
- Sometimes yes, sometimes no. Sheep's wool batts cost more per m² than mineral wool. Sprayed cork wall insulation costs more per m² than basic render — but roughly a third of the cost of EWI for the same thermal performance, with a 40+ year service life that wipes out the repaint cycle. Total cost of ownership over 25 years is usually lower than the cheapest petrochemical alternative.
- Does sustainable insulation perform as well as foam insulation?
- For wall insulation, yes. Sprayed cork has a thermal conductivity of around 0.065 W/mK and delivers up to 30% improvement in wall U-value on solid walls. It also outperforms most foam systems on moisture management because it stays breathable — so it actively prevents the interstitial condensation that often degrades foam-insulated solid walls within 10–15 years.
- Is sustainable insulation fire-safe?
- Quality sustainable insulation is. Our sprayed cork system is rated B-s1, d0 to EN 13501, which makes it suitable for residential, commercial, and industrial use including buildings over 11 m where compliant. That's a stricter fire rating than many cheaper foam systems.
- Can sustainable insulation be used on listed buildings?
- Yes — and it's often the only option. Listed and pre-1920s solid-wall buildings need breathable wall insulation to avoid trapping moisture in old brickwork. Sprayed cork is widely specified for these projects because it's vapour-permeable, sympathetic to original architectural detail (only 3–6 mm thick), and reversible compared to EWI.