Insulation plays a vital role in reducing energy usage, but the materials we choose also have long-term environmental consequences. This guide breaks down the sustainability profiles of popular insulation materials, highlights more eco-friendly alternatives, and outlines how the industry is evolving towards greener solutions.
Types of Materials Making a Positive Impact
Some insulation materials are now being recognised for their lower environmental footprint and renewable properties. These include:
- Hemp insulation – fast-growing, carbon-sequestering, and compostable.
- Cellulose – made from recycled paper, low embodied energy, and great for retrofits.
- Wood fibre boards – renewable, breathable, and recyclable.
- Sheep’s wool – natural, biodegradable, and great for moisture regulation.
These materials help reduce a building’s lifetime emissions, especially in low-energy, Passivhaus, or eco-renovation projects.
Is plastic-based Insulation a concern?
Despite environmental concerns, plastic-derived insulation like PIR, phenolic foam, and polystyrene (EPS/XPS) remain widely used for the following reasons:
Why People Still Use Plastic-Based Insulation:
- Low cost per m²
- Exceptional thermal performance (especially where space is tight)
- Lightweight and easy to install
- Long lifespan (30+ years)
What are the Long-Term Impacts?
- High embodied carbon
- Made from petrochemicals
- Difficult to recycle
- Can contribute to microplastic pollution over time
The future outlook for plastic
Regulations are likely to tighten around embodied carbon limits, and manufacturers are developing low-emission versions or hybrid systems to bridge the gap between performance and sustainability.
Fiberglass & Stone Wool: Where They Stand
Fiberglass and stone wool materials are non-combustible, long-lasting, and semi-sustainable, making them a middle-ground option between plastic foams and natural alternatives.
Environmental Ranking of Insulation Materials
The table below ranks from the highest to lowest environmental impact
| Material | Environmental Impact | Key Concerns |
|---|---|---|
| Expanded Polystyrene (EPS) | ❌ High | Petrochemical base, non-biodegradable, difficult to recycle |
| Extruded Polystyrene (XPS) | ❌ High | High embodied carbon, uses harmful blowing agents |
| Polyurethane (PUR) / PIR | ⚠️ Moderate to High | Not recyclable, toxic emissions during production and disposal |
| Fiberglass | ⚠️ Moderate | Energy-intensive to produce, skin/respiratory irritation during installation |
| Stone Wool (Rockwool) | ⚠️ Moderate | High manufacturing temperatures, not biodegradable |
| Cellulose (Recycled Paper) | ✅ Low | May settle over time, requires treatment to resist mould/fire |
| Sheep’s Wool | ✅ Low | Can attract pests if untreated, often more expensive |
| Hemp Insulation | ✅ Low | Limited manufacturing infrastructure, typically higher cost |
| Wood Fibre Boards | ✅ Low | Renewable, breathable, often carbon-neutral |
Why is Natural Insulation is gaining popularity?
Natural insulations such as hemp, sheep’s wool, and cellulose are popular because they have a lower carbon impact and better indoor air quality, and are currently being used in:
- Heritage homes (where breathability is key)
- Timber frame buildings
- Low-carbon new builds (e.g., Passivhaus, eco-homes)
- Renovation projects seeking healthy, non-toxic interiors
Cost Considerations:
- Usually 20–40% more expensive than conventional options
- Labour may cost more if specialist installation is required
- BUT: Lower carbon impact and better indoor air quality
Useful tips when installing Natural Fibre:
- Moisture sensitivity if not paired with proper vapour barriers
- Rodent/pest risks without adequate treatment
- Can require fire-retardant additives
- The thickness often needed is greater than synthetic alternatives
What’s Popular Right Now?
Mineral wool (stone wool and fiberglass) remains the most widely used due to:
- Strong fire and acoustic performance
- Moderate price
- Availability at scale
- B2B acceptance across commercial builds
PIR and EPS are still leading in space-constrained areas (e.g., flat roofs, floors), despite their environmental cost.
Sustainability & Innovation is the Future of Insulation
The insulation market is steadily moving toward circularity, low-carbon manufacturing, and bio-based materials.
Trends to watch include:
Carbon-neutral insulation made from agricultural waste. Hybrid systems combining performance + sustainability. Recyclable foams with lower embodied carbon. Increased regulation around embodied energy and VOC emissions.
As demand grows for healthier, greener homes and buildings, natural and recycled insulation will likely dominate future specs, particularly in residential and eco-conscious B2B projects.