What are SIPs?
Structurally Insulated Panels (SIPs) are made from two outer layers of oriented strand board (OSB) bonded around a high-performance expanded polystyrene (EPS) core. This creates a panel that’s lightweight, incredibly strong — up to seven times stronger than a timber frame — and exceptionally well-insulated.
Why Build with SIPs?
SIPs deliver outstanding thermal performance and airtightness, meaning less energy is needed to heat the building and better indoor air quality for occupants. You can explore the full range of eco-benefits and project advantages they offer.
A Proven Building Method
SIPs have been widely used in the USA, Canada, Japan and across Europe since the 1950s. In the UK, their popularity is growing fast thanks to increasing sustainability awareness, rising energy costs, and a push for local, low-impact construction solutions.
Fast, Efficient & Reliable
Used for walls, roofs and floors, SIPs create a solid, well-insulated building envelope. Panels are joined with timber, insulated I-beams, or SIP splines and fixed in place using a timber sole plate and ring beam. The result is a fast, precise build with no risk of compression shrinkage or cold bridging — common issues in traditional masonary and timber frame struction
Benefits
The SIPs construction method offers many project benefits for architects, planners, developers and self-builders. Below are just some of the key advantages of using SIPs instead of more traditional building methods – we hope you’ll be amazed at the potential they offer.
OSB3 – 11mm Sterling Board
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BBA approved and conforms to Eurocodes
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Precision-engineered structural board
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Responsibly sourced and FSC® certified
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Produced with Zero added formaldehyde
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Specially treated for moisture resistance
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Natural thermal insulator
EPS – Expanded Polystyrene (min 70 grade)
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BBA approved and conforms to Eurocodes
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Precision-engineered structural insulation board
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100% recyclable, non-toxic and biologically inert
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Free from CFCs or HCFCs gases
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Contains a flame-retardant graphite additive
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High strength-to-weight ratio
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Very low thermal conductivity
C24 Grade – Structural Timber
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BBA approved and conforms to Eurocodes
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Responsibly sourced and FSC® certified
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100% recyclable, non-toxic and biologically inert
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Specially treated for moisture resistance
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Natural thermal insulator, low thermal conductivity
Glulam – Structural Timber Beams
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BBA approved and conforms to Eurocodes
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Responsibly sourced and FSC® certified
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Incredibly strong over long spans
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Reduced carbon footprint Vs using steel beams
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100% recyclable, non-toxic and biologically inert
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Natural thermal insulator, low thermal conductivity
Panel Options
Panel Options | Garden Office (-30m²) | Garden Annex (+30m²) | House or Apartment |
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Walls SIP panel thickness | 96mm | 172mm | 172mm/222mm |
Walls EPS insulation thickness | 74mm | 150mm | 150mm/200mm |
Walls U-Value (thermal resistance) | 0.38 | 0.18 *with membranes | 0.18/0.14*with membranes |
Wall Panel Weight (2.4m) | 46.1kg | 49.1kg | 49.1kg |
Wall Panel Weight (3m) | N/A | 58.5kg | 58.5kg |
Roof SIP panel thickness | 120mm | 222mm | 222mm |
Roof EPS insulation thickness | 98mm | 200mm | 200mm |
Roof U-Value (thermal resistance) | 0.29 | 0.11 *with membranes | 0.11/0.14 *with membranes |
Roof Panel Weight (2.4m) | 47kg | 51.2kg | 51.2kg |
Roof Panel Weight (3m) | N/A | 61.2kg | 61.2kg |
Floor SIP panel thickness | 96mm | 222mm | N/A |
Floors EPS insulation thickness | 74mm | 150mm | N/A |
Floors U-Value (thermal resistance) | 0.38 | 0.19 | N/A |
OSB skins thickness | 11mm | 11mm | 11mm |
Max panel length | 2.4m or 3m | 2.4m or 3m | 2.4m or 3m |
Max panel width | 1.2m | 1.2m | 1.2m |
How are Ecologic SIPs made?
Precision-Made SIPs, Built In-House
All our SIPs are manufactured at our 240sqm New Forest workshop, ensuring complete control over quality, safety, and precision. We bond OSB3 skins to EPS foam using a high-strength polyurethane adhesive, then cure the panels under pressure in our custom press.
Polyurethane creates an exceptionally strong bond — once cured, the laminated SIP panel can handle incredible structural stresses.
Tested & Proven Performance
Want to see the strength for yourself? Download our results and certification from a UKAS-accredited testing lab, which assessed the compressive and tensile resistance of our SIPs. The findings are also backed by a third-party Chartered Structural Engineer's report.
Learn more about how we build our panels on our manufacturing page.
Why use SIPs Vs Bricks?
Hear from a local builder who has been using traditional methods (bricks and blocks) for over a decade, and has now decided to switch to SIPs. Here is an honest account of the major benefits of the system, both for the planet and your project.