GuideSIP PanelsUK Construction

The Complete Guide to SIP Panels UK 2025: Everything You Need to Know

18 November 2025Benjamin Alder-Howe2 min read

SIP panels are transforming UK construction. This comprehensive guide covers everything you need to know about Structural Insulated Panels—from technical specifications to real-world applications.

What Are SIP Panels?

Structural Insulated Panels (SIPs) are high-performance building panels used in walls, roofs, and floors. They consist of a foam core (typically PIR - polyisocyanurate) sandwiched between two OSB (oriented strand board) facings.

How SIP Panels Work

SIP panels achieve superior performance through three mechanisms:

  • Conductive Resistance: The foam core resists heat flow
  • Convective Barriers: The sealed structure prevents air movement
  • Airtightness: Properly installed panels create an airtight envelope

Types of SIP Panels Available

ThicknessU-ValueBest For
72mm0.396 W/m²KStorage, non-heated spaces
97mm0.264 W/m²KOccasional-use buildings
122mm0.209 W/m²KGarden rooms, offices (most popular)
142mm0.179 W/m²KExtensions, new builds
172mm0.144 W/m²KPremium efficiency projects

10 Key Benefits of SIP Panels

  1. Superior thermal performance
  2. Faster build times (up to 50% quicker)
  3. Excellent airtightness
  4. Cost-effective over building lifetime
  5. Versatile applications
  6. Reduced labour requirements
  7. Consistent quality (factory manufactured)
  8. Lower heating costs
  9. Environmentally friendly
  10. Long lifespan (60+ years)

Applications

  • Garden rooms and offices
  • Home extensions
  • New builds and self-builds
  • Roof insulation and replacement
  • Commercial buildings
  • Retrofit projects

Building Regulations

UK Building Regulations Part L require walls to achieve U-values of ≤0.18 W/m²K. Our 142mm and 172mm panels meet or exceed these requirements.

Installation Process

  1. Prepare level foundation
  2. Install base plate
  3. Erect wall panels
  4. Connect panels with PIR splines
  5. Install roof panels
  6. Seal all joints
  7. Apply finishing materials

Cost Analysis

Material costs range from £88.90-£133.40/m² depending on thickness. Complete project costs including installation typically range from £1,000-1,800/m².

Choosing the Right Panel

Consider your building type, heating requirements, and budget. For most garden rooms and home offices, the 122mm panel offers the best balance of performance and cost.

Ready to Start Your Project?

Whether you're building a garden room, extension, or full home, our SIP panels provide superior insulation and fast construction.